Post by: Donster on December 14, 2018, 03:15:35 pm
Thnx,
\D
Post by: GTRS Fiero on December 14, 2018, 05:53:49 pm
So, the idle hasn't been good, as long as you've had the car? You need to check the readings for the CTS & IAC.
Post by: GTRS Fiero on December 14, 2018, 10:57:58 pm
Post by: Donster on December 15, 2018, 04:25:06 am
Post by: GTRS Fiero on December 15, 2018, 08:03:08 am
Post by: TopNotch on December 15, 2018, 08:53:41 am
Post by: Fierofool on December 15, 2018, 09:08:24 am
Post by: Donster on December 20, 2018, 06:37:12 am
I have already replaced the MAP sensor, but it seems I replaced a good one with a good one. I also have a spare TPS, but wanted to ask first.
So, does it sound like it is the EGR valve? Should I just make a cover/gasket for it and block it? Have heard other success stories of blocked EGRs on Dukes.
Also a question: I noticed that the nipple for the vacuum line on the top of the EGR valve rotates/spins freely. Is that how it should be?
Thanks,
\D
Post by: Fierofool on December 20, 2018, 03:12:09 pm
It sounds like you have a universal EGR valve. I've often wondered how a vacuum can be applied to the diaphragm if the vacuum chamber cover can rotate. If it can rotate, seems to me that there's not a seal between it and the body of the valve, so there's no seal of the vacuum chamber. But I'm no engineer.
Post by: GTRS Fiero on December 20, 2018, 06:30:37 pm
Post by: TopNotch on December 20, 2018, 09:32:48 pm
Post by: GTRS Fiero on December 20, 2018, 09:34:48 pm
Post by: TopNotch on December 20, 2018, 09:39:40 pm
Post by: GTRS Fiero on December 20, 2018, 09:43:21 pm
Post by: Donster on December 21, 2018, 05:56:37 am
Did you plug the vacuum line for the EGR, when you unplugged the line from the EGR?
Plugged both directions, no change.
Turns out EGR valves are rather difficult to find new here in Germany.
Again, does anyone have experience with blocking out the EGR on an 88 L4? I can have a cover-plate and gasket made within minutes and permanently plug the hoses.
Thanks
\D
Post by: GTRS Fiero on December 21, 2018, 07:05:48 am
Was there vacuum on the EGR vacuum line? It would seem that, when you unplugged it, there should have been a change, unless the line has a leak somewhere.
Post by: TopNotch on December 21, 2018, 07:49:09 am
I'm feeling dense, tonight. Does the back pressure make the EGR open or close?
Open. You don't want the EGR open at either wide-open-throttle or idle. At idle, there is a lot of vacuum, but no back pressure. At wide-open-throttle, there is plenty of back pressure, but very low vacuum. At cruising speed, you get both, and the EGR opens. It's a very simple system on the duke, with no electronics or solenoid involved.
Post by: GTRS Fiero on December 21, 2018, 07:56:54 am
Post by: Fierofool on December 21, 2018, 08:28:11 am
Post by: TopNotch on December 21, 2018, 11:08:49 am
You can test the EGR valve by placing your fingers underneath and feeling the diaphragm. Push up on it and cap the nipple with a finger. If the diaphragm moves down, the valve is bad.
Unfortunately, this test does not work on a duke EGR. About the only test you can do is push up the diaphragm while the engine is idling. If there is no change, you know the EGR is leaking or stuck open.
Post by: Donster on December 21, 2018, 11:18:42 am
Again, does anyone have experience with blocking out the EGR on an 88 L4? I can have a cover-plate and gasket made within minutes and permanently plug the hoses.
Thanks
\D
Anyone?
Post by: TopNotch on December 21, 2018, 01:06:04 pm
Post by: Donster on December 22, 2018, 08:16:40 am
Will replace plugs next.
\D
Post by: GTRS Fiero on December 22, 2018, 08:20:04 am
Post by: Donster on December 22, 2018, 10:51:10 am
I'm no expert on the Duke, but I suspect a sensor issue. The IAC or CTS, maybe.
They would both throw an error code.
\D
Post by: GTRS Fiero on December 22, 2018, 11:20:12 am
Post by: Fierofool on December 22, 2018, 06:34:27 pm
Post by: GTRS Fiero on December 22, 2018, 08:23:47 pm
For the CTS, there are only certain conditions under which it will set a code. Neither of them are because the sensor is bad.
It may or may not matter, but these were all V6 applications.
Post by: GTRS Fiero on December 22, 2018, 08:32:02 pm
http://www.fiero.nl/forum/Forum2/HTML/142073.html
Post by: Donster on December 28, 2018, 08:39:55 am
Does run a bit better but idle issue persists.
Also adjusted the TV cable, so it shifts much better now also.
Tomorrow I'll replace the IAC and report back.
\D
Post by: GTRS Fiero on December 28, 2018, 09:08:56 am
I used to have a Firehawk that I bought used at 109K miles. The car ran very well, but while things were apart in front (routine used car maintenance), I decided to change the plugs. Anyone who has done this will know that you have to either drop the engine or remove a fender to access some plugs. Anyway, I found that it still had the factory plugs, which still looked good. Since I had them out, I replaced them, unfortunately with platinum plugs.
I'm not sure that age is a problem for the plugs. I am curious how your plugs looked, when you pulled them.
Post by: Raydar on December 28, 2018, 09:57:11 am
...
Again, does anyone have experience with blocking out the EGR on an 88 L4? I can have a cover-plate and gasket made within minutes and permanently plug the hoses.
Thanks
\D
I was thinking about deleting mine but, like the V6, there are some timing (and I thing fueling) parameters that are changed to account for the EGR. (I have the software, and found those changes.) Deleting the EGR without a reprogram would likely make it ping, at best.
I didn't bother with mine. Didn't seem worth the trouble.
Post by: Donster on December 28, 2018, 01:22:16 pm
...
Again, does anyone have experience with blocking out the EGR on an 88 L4? I can have a cover-plate and gasket made within minutes and permanently plug the hoses.
Thanks
\D
I was thinking about deleting mine but, like the V6, there are some timing (and I thing fueling) parameters that are changed to account for the EGR. (I have the software, and found those changes.) Deleting the EGR without a reprogram would likely make it ping, at best.
I didn't bother with mine. Didn't seem worth the trouble.
I thought on the 88 Duke, the EGR doesn't run over the ECM, hence no software changes needed? Some on PFF said the older Dukes started knocking, but the majority reported no negative behavior. Mine isn't knocking, but I will replace it with new EGR anyways.
\D
Post by: GTRS Fiero on December 28, 2018, 07:28:11 pm
Post by: Fierofool on December 28, 2018, 07:38:44 pm
Post by: GTRS Fiero on December 28, 2018, 07:40:25 pm
Post by: TopNotch on December 28, 2018, 09:25:43 pm
Post by: Donster on December 29, 2018, 08:01:39 am
Vacuum lines are all good.......but wait........sprayed starter fluid around the throttle body, and low and behold, the up & down idle went away! Turns out the gasket for the throttle body is leaking/sucking air!
Problem is, I can't find this gasket anywhere. Has anybody had to replace this in the past? Can't ID it in the P22 either. :-(
\D
Post by: GTRS Fiero on December 29, 2018, 11:24:07 am
Felpro 60764 Throttle Body Gasket - Direct Fit, Sold Individually
Part Number: 60764
Post by: Fierofool on December 29, 2018, 05:19:14 pm
Post by: Raydar on December 29, 2018, 10:57:13 pm
...
I thought on the 88 Duke, the EGR doesn't run over the ECM, hence no software changes needed? Some on PFF said the older Dukes started knocking, but the majority reported no negative behavior. Mine isn't knocking, but I will replace it with new EGR anyways.
\D
The ECM doesn't control or monitor the EGR, as the V6 does, but it does assume it's there, and operational.
My first 88 Duke failed emissions for high NOx. I replaced the EGR valve, and it passed. I also noticed that its slight tendency to ping went away, afterwards.
The only time the EGR really does anything is at a steady-state cruise. Moderate RPM (2-3K?) and moderate steady throttle.
The ECM has a bump in the ignition timing table that coincides with that set of conditions. I have to believe that's to accommodate the EGR.
My tuning software is on a different computer, or I'd post the graph. It's easier to see than it is to describe.
Post by: Donster on January 08, 2019, 02:02:10 am
Turns out, RockAuto.com ships to Germany at reasonable prices for low cost items. (Gasket = $2,49 + $9,50 express shipping). Expected to arrive within 4-6 business days. We shall see.
I think I will plan a trip to the US, make a list of all the small hard to get parts, take an extra suitcase and combine it with a well deserved vacation. Heaven knows I don't get enough vacation working in Germany! :-)
\D
Post by: GTRS Fiero on January 08, 2019, 05:05:02 am
Post by: TopNotch on January 09, 2019, 10:20:01 am
Post by: GTRS Fiero on January 11, 2019, 10:32:31 pm
Turns out, RockAuto.com ships to Germany at reasonable prices for low cost items. (Gasket = $2,49 + $9,50 express shipping). Expected to arrive within 4-6 business days. We shall see.
Gasket for $2.49 is good. It's about $5, here.
Post by: Donster on January 12, 2019, 09:59:58 am
So here is what has been done:
All vacuum lines checked
New plugs
AGR valve blocked
New MAP sensor
New IAC valve
New TPS
New Throttle Body Housing gasket (today)
New TB injector (today, identical)
..........now I'll replace the ignition cables (Monday)....then I have checked or replaced just about everything I can think of.
Post by: GTRS Fiero on January 12, 2019, 10:32:14 am
I don't know about the TB injector.
Have you replaced the CTS or MAT sensors? If it runs OK when cold, but has issues when warm, that means that the preset values are fine, but the problem is sensor input. The master sensor is the CTS sensor. The CTS and MAT sensors work as a pair. I don't know if you could test the CTS by unplugging it or shorting it. Basically, make the ECU think that the engine is cold.
The ignition cables should not be the issue, because they do not go bad when the engine gets warm.
Post by: Donster on January 12, 2019, 12:51:20 pm
Post by: GTRS Fiero on January 12, 2019, 01:36:08 pm
Also called IAT = Intake Air Temperature
If this fixes the problem, I'd like a pic of the sensor installed.
The MAP = Manifold Air Pressure sensor probably isn't the problem, although it is a possibility.
I did an article on sensors and locations for the V6, since that is what I have, but maybe should do one for the L4. Much more difficult, though.
Post by: Donster on January 12, 2019, 03:28:33 pm
"AGR valve"?
Got German and English mixed up there. ARG = Abgas-Rücklauf-Ventil, in English that would be Exhaust Gas Recirculation Valve, so AGR=EGR :-)
\D
Post by: Raydar on January 12, 2019, 10:58:00 pm
I don't know if you could test the CTS by unplugging it or shorting it. Basically, make the ECU think that the engine is cold.
...
Unplugging a sensor will (of course) set the code for that particular sensor.
If I understand correctly, it will also cause a pre-programmed "nominal" value to be plugged in to the operating program. Something that may not be optimal, but will allow the engine to at least run safely, and not damage itself. It will also make a "best guess" as to what it should be doing, based upon input from the other sensors.
Post by: GTRS Fiero on January 12, 2019, 11:17:54 pm
You can also test with a multimeter, with key on after the engine is hot.
Post by: Donster on January 19, 2019, 07:10:53 am
Question: Could an incorrectly wired Oil Pressure Sensor have an influence on the idle?
Thnx.
\D
Post by: Donster on January 19, 2019, 07:13:35 am
I did an article on sensors and locations for the V6, since that is what I have, but maybe should do one for the L4. Much more difficult, though.
It would certainly help those unfortunate L4 owners. ;D
\D
Post by: Donster on January 19, 2019, 07:17:47 am
Unplugging a sensor will (of course) set the code for that particular sensor.BTW: I unplugged the CTS while the engine was running, but it did not throw a code. Should I unplug it when the engine is still off and then run the motor for a while?
\D
Post by: Fierofool on January 19, 2019, 08:45:14 am
I got to a shop here in town and a scan showed the CTS was reading 28*f and there had been no trouble code set. I unplugged it and drove down to the parts store and got a new CTS. Only during the drive did the light come on and set a code.
Post by: GTRS Fiero on January 19, 2019, 09:37:17 am
I did an article on sensors and locations for the V6, since that is what I have, but maybe should do one for the L4. Much more difficult, though.
It would certainly help those unfortunate L4 owners. ;D
\D
Well, I need pictures.
Post by: GTRS Fiero on January 19, 2019, 09:38:22 am
Unplugging a sensor will (of course) set the code for that particular sensor.BTW: I unplugged the CTS while the engine was running, but it did not throw a code. Should I unplug it when the engine is still off and then run the motor for a while?
\D
Did unplugging the CTS make any difference in the idle?
Post by: Donster on January 19, 2019, 09:57:16 am
Did unplugging the CTS make any difference in the idle?
None.
Post by: GTRS Fiero on January 19, 2019, 10:02:18 am
Post by: Donster on January 19, 2019, 01:11:31 pm
Unplugging the MAT sensor also did no good?
Also no change.
Post by: GTRS Fiero on January 19, 2019, 01:14:24 pm
Hmmm. What happens if you remove the thermostat?
Post by: GTRS Fiero on January 20, 2019, 08:11:44 am
Post by: GTRS Fiero on January 20, 2019, 08:38:33 am
Post by: Donster on January 20, 2019, 01:27:46 pm
Question: Could an incorrectly wired Oil Pressure Sensor have an influence on the idle?
Anybody?
After thinking about this, have you run WinALDL on this? I don't know if it works on the '88 Duke or not, but you need to know what values the ECU is reading.
Can't do WinALDL on an 87 or 88 Duke, software is not compatible.
I think I figured it out. It's voltage to the ECU. Either a bad power, or a bad ground.Can you elaborate?
Thnx,
\D
Post by: GTRS Fiero on January 20, 2019, 01:37:23 pm
Have you ever checked their ECM supply voltage to see if it is changing? Some people have reported that adding ground wires have help their idle.
In the ECM prom there is actually a section that controls idle speed depending on battery supply voltage.
If the voltage dropps to 8 volts, the idle speed would be adjusted to 1200 rpm. At 14.4v it drops back to 900 rpm.
Here is a table:
Volts Idle
8.0 1000
9.6 1000
11.2 900
12.8 900
14.4 900
If the power to the ECM changes you could get into an loop where voltage drops, idle is increased, voltage comes up, idle is decreased. Sound familiar?
Try a battery charger to see what happens. Maybe have the voltage regulator in the alternator tested.
Maybe feed a stable 12V to the ECM.
Put a Volt meter on the power to the ECM.
Post by: GTRS Fiero on January 20, 2019, 04:38:16 pm
Post by: Donster on January 22, 2019, 11:24:03 am
\D
Post by: Donster on January 22, 2019, 11:27:57 am
I think I figured it out. It's voltage to the ECU. Either a bad power, or a bad ground.
I don't think this would be temperature dependent. True?
\D
Post by: Donster on January 22, 2019, 02:29:13 pm
I did an article on sensors and locations for the V6, since that is what I have, but maybe should do one for the L4. Much more difficult, though.
It would certainly help those unfortunate L4 owners. ;D
\D
Well, I need pictures.
Let me know what to take pictures of, and I can provide.
\D
Post by: GTRS Fiero on January 22, 2019, 06:34:15 pm
I think I figured it out. It's voltage to the ECU. Either a bad power, or a bad ground.
I don't think this would be temperature dependent. True?
\D
Well, everything runs OK on pre-set values. The issue obviously occurs after the ECU starts running things off of the sensors. Since the sensors aren't the issue, the issue is somewhere with the ECU itself. Unless the ECU is bad, the issue is voltage. The ECU does not start running off the sensors until the engine has warmed up, so yes, something with the engine being warm.
Since voltage has a dramatic effect on the ECU, that is a highly likely source of the issue.
In theory, when you unplugged the CTS, resistance should have gone to infinite, as in cold. Unless there is a short somewhere.
Keep in mind that the L4 is foreign to me.
Post by: GTRS Fiero on January 22, 2019, 06:52:02 pm
Let me know what to take pictures of, and I can provide.
\D
I sent you an email. I can't do more than start on this, for now. I have some content, but the L4 is much more difficult than the V6, because there are 3 different versions of the L4: 84, 85-86, and 87-88. I am not enough of an expert to know all the differences. Basically, I don't know what I don't know.
If you can help with this, that would be great. I'm trying to show how things should be, so only stock, where possible. I'm afraid that probably 90% of the pictures in the newsletters are my Fiero, or parts at the house. Since my Fiero is no longer stock, getting pictures is difficult.
Post by: Donster on January 23, 2019, 10:36:59 am
\D
Post by: GTRS Fiero on January 23, 2019, 05:45:59 pm
Post by: Fierofool on January 25, 2019, 07:00:31 pm
Post by: Donster on January 26, 2019, 09:10:34 am
I sent David Brill an email earlier in the week asking what happened to The Phoenix and Purple Haze and haven't gotten a response, yet.
Much obliged Charlie. LMK if you hear something.
BTW: Replaced MAT today, no change. :-(
Reset IAC (Used Ogre's procedure for Idle Stop.....ECM A&B shorted with ignition on, heard the IAC clicking, disconnected IAC, took jumper off A&B and turned ignition off, plugged IAC back up, disconnected and reconnected battery, drove 35 mph for 30 miles).........no change.
So now I am at a loss, might get a new EGR and take the block-off plate back out and still waiting on new spark plug cables (although there are some people here that doubt they could be the issue) :-)
Or, perhaps we can try this: Which one of you Duke Experts (Pat, Steve, Charlie?) wants to come over to Germany and help me figure this out?? LOL
Greetings from good cold ol' Germany,
\D
Post by: Fierofool on January 26, 2019, 12:42:33 pm
Or, perhaps we can try this: Which one of you Duke Experts (Pat, Steve, Charlie?) wants to come over to Germany and help me figure this out?? LOL
\D
Two things eliminate me. Cold weather and I know very very little about the Duke. Having made that know, I will offer this. The high idle may be caused by a vacuum leak somewhere. I have used a small handheld propane torch to find vacuum leaks.
The air mixer shield on the end of the torch will unscrew, leaving just the gas jet orifice on the end of the tube. I've taken a properly sized rubber hose about a foot in length and slid it over the end, lightly turned on the valve and with the engine running, passed the end of the tube over vacuum lines and connections and around mating surfaces. When you find the source of the leak, the engine rpm will increase. There's no likelihood of an explosion. The only thing that might happen is that should you get around a leaky spark plug wire, it might briefly ignite the end of the hose, but because you don't have the air mixer there, it won't stay lighted.
Just got a text from David and he said he still has the cars and would like to find them a new home. I asked for a series of pics and info on each and I'll put them in The Market Place for him.
Post by: Donster on January 31, 2019, 06:47:37 am
Installed it, while my hands were about to freeze off........no change, idle still hunting, but in general, the engine runs better.
Spark plug cables should arrive tomorrow morning. After they are in and it still has idle issues, I'm going to tear out all vacuum lines and replace them.
Just to recap -- 88 Duke, all original. Engine runs great, idles good when cold. As soon as it warms up, the idle starts hunting.
So here is what has been done:
All vacuum lines checked
New spark plugs
EGR valve blocked
New MAP sensor
New IAC valve
New TPS
New Throttle Body Housing gasket
New TB injector
New MAT sensor
New EGR valve
Question: Could the ignition coils also be the problem?
\D
Post by: GTRS Fiero on January 31, 2019, 08:10:31 am
New IAC does not equal good IAC.
Post by: TopNotch on January 31, 2019, 09:57:52 am
Post by: Donster on January 31, 2019, 11:19:56 am
Post by: Donster on February 01, 2019, 11:00:52 am
Tomorrow I'll be at my friend's shop, will check vacuum lines AGAIN.
Post by: Raydar on February 01, 2019, 11:07:10 am
Then again, if you have already replaced the entire throttle body, it should be preset.
How does the car run, out on the open road? Good acceleration with no stumbles?
Post by: Donster on February 01, 2019, 11:13:50 am
How does the car run, out on the open road? Good acceleration with no stumbles?
Runs like a charm, even good gas mileage, no stumbles. Only thing I still need to replace is the exhaust, as it rattles when in "P" or "N".
Other than that and some electrical gremlins in the dash, it's a great little L4
\D
Post by: Raydar on February 01, 2019, 12:24:35 pm
How does the car run, out on the open road? Good acceleration with no stumbles?
Runs like a charm, even good gas mileage, no stumbles. Only thing I still need to replace is the exhaust, as it rattles when in "P" or "N".
Other than that and some electrical gremlins in the dash, it's a great little L4
\D
Okay. That would seem to eliminate a bad fuel pump or clogged filter. (Higher demand for fuel would seem to make either of those issues much more pronounced.)
#headscratch
Post by: Fierofool on February 01, 2019, 12:34:49 pm
I did have a problem with high idle, and was never able to overcome it. I don't remember, but does the 88 have an Intake Air Temperature sensor or Thermac sensor in it's intake system? Hunting idle is usually the result of the ECM trying to correct for information sent by one of it's sensors. An air leak will result in a lean burn. The ECM dumps fuel and it becomes a rich burn, so it cuts back fuel. The o/2 sensor detects a lean condition, and you get the same cycle. All temperature sensors can be tested for accuracy, including new ones, by using a multimeter and the information in this chart:
http://www.gafiero.org/bbs/index.php?topic=641.msg4644#msg4644
Post by: Raydar on February 01, 2019, 04:32:01 pm
Just be watchful of that 4500 rpm redline. I found it was very easy to overdo it in First and Second in my 88 Lil Duke Coupe.
I did have a problem with high idle, and was never able to overcome it. I don't remember, but does the 88 have an Intake Air Temperature sensor or Thermac sensor in it's intake system?
...
It's in the intake manifold.
From Ogre's cave...
MAT sensor. 87+ 4 cylinders gain an additional sensor. The MAT (Manifold Air Temperature) sensor is located in the intake manifold to the right of the TBI unit. DO NOT over tighten the MAT sensor or you may split the intake manifold.
Ogre has probably researched the Duke as much as anybody.
http://fierocave.shorturl.com/
Post by: Donster on February 01, 2019, 05:26:40 pm
Like I said, will tear out ALL vacuum lines tomorrow, except for brake booster, and go from there.
The engine has really gotten better, but occasionally, the idle hunts when temp is up, which baffles me.
Still thinking about replacing coils???
Couldn't believe the improvement of radio reception, after replacing ground connections and spark plug cables. LOL!!!
\D
Post by: Raydar on February 01, 2019, 05:37:37 pm
If nothing else, I'll warm it up, and start unplugging stuff, and measuring sensor resistance. :D
(I'm certainly not an expert on this engine. Charlie and Pat have messed with them a lot more than I have.)
Edit - I'll be really surprised if it's related to the coils. I'd be more inclined to think it's related to the DC voltage available to the ECM.
(I went back and reread the entire thread, this morning. The ECM posts were... intriguing.)
2nd edit. The "idle speed vs ECM volts can be reprogrammed", if I remember correctly. I might have to have a look.
Or it might be "injector pulse width vs volts".
Post by: Donster on February 02, 2019, 08:28:47 am
Intake manifold and TB housing are all sealed. Spent 2 hours doing nothing but hunting down possible vacuum leaks.
Question: Could it be the injector? While I'm asking, does anyone, or maybe the club, have a spare 88 L4 TB injector they could sell and ship me?
BTW: ECM has good stable power and ground.
Thanks.
\D
Post by: GTRS Fiero on February 03, 2019, 09:03:01 am
Post by: Donster on February 03, 2019, 11:08:17 am
Post by: GTRS Fiero on February 03, 2019, 01:40:01 pm
Post by: Raydar on February 03, 2019, 08:08:58 pm
Post by: GTRS Fiero on February 03, 2019, 08:38:24 pm
Post by: Donster on February 03, 2019, 09:45:13 pm
\D
Post by: GTRS Fiero on February 03, 2019, 09:48:35 pm
Could the O2 sensor be the culprit? Haven't checked it yet. How do you best test it?
\D
I think the MAP and O2 sensors could also be suspects.
Sure could.
Post by: GTRS Fiero on February 03, 2019, 09:49:05 pm
I'm doubting the ignition coils, and you replaced the intake gasket. O2 sensor?
New IAC does not equal good IAC.
It's been suggested once or twice.
Usually, a bad O2 results in smelly exhaust.
Post by: Donster on February 05, 2019, 06:50:51 am
\D
Post by: Fierofool on February 05, 2019, 08:53:41 am
Post by: Raydar on February 05, 2019, 10:08:27 pm
So how does one test O2 sensor?
\D
Once the engine is warmed up, unplug it. It will set the O2 sensor code (pretty much guaranteed) and should turn on the CEL light.
But if the idle settles down, the ECM would seem to be fighting with what the O2 sensor is feeding it.
If that's the case, I would be inclined to replace it. No guarantees, but what else ya' gonna do?
I don't think it's the coils or associated pieces.
Edit - If you've got a scan tool, it should show ~.445 volts (DC) when the O2 is cold. (That value is "plugged in" to the PCM, and is used as a default, until the O2 warms up and starts responding to actual exhaust readings.)
Once it warms up, it should bounce back and forth between .1 and .8 volts (or thereabouts.) It should spend about half the time on either side of .445 volts.
If it parks on one side or the other, it thinks it's seeing a continuous lean or rich condition. Towards .8 is rich. Towards .1 is lean. If you are accelerating or decelerating, a temporarily full rich or full lean condition is normal.
The O2 CAN lie. At one point, the one on my 4.9 indicated full lean (very low voltage.) The PCM compensated by dumping in as much fuel as it could. Failed a smog test horribly. Also killed my catalyst. My gas mileage was also crap.
Post by: Fierofool on February 06, 2019, 11:04:14 pm
Post by: Donster on February 07, 2019, 08:56:42 am
BTW: Installed new O2 sensor today, ran the car hot, no change, idle still hunting. :(
\D
Post by: Raydar on February 07, 2019, 05:18:52 pm
Thanks Charlie.........good reading.
BTW: Installed new O2 sensor today, ran the car hot, no change, idle still hunting. :(
\D
GAAAAHHHH!!
Post by: GTRS Fiero on February 07, 2019, 06:02:12 pm
Post by: Donster on February 11, 2019, 03:43:40 am
Should be here next Monday.
If I still can't get rid of the issue, I'm willing to replace the ECM (minus the PROM of course).
So, just in case, does anyone have a spare 88 Auto-Duke ECM?
\D
Post by: Donster on February 15, 2019, 12:24:30 pm
New IAC - RUNS STEADY! ;D ;D ;D
Must have had a bad IAC out of the box. :(
Thanks all!
\D
Post by: Raydar on February 15, 2019, 02:27:40 pm
Ready for this?
New IAC - RUNS STEADY! ;D ;D ;D
....
I'm happy to hear it! This was turning into a real head-scratcher.
Post by: Donster on February 15, 2019, 02:39:59 pm
Post by: GTRS Fiero on February 15, 2019, 03:46:17 pm
Post by: Donster on February 25, 2019, 11:32:14 am
We ran her real hot yesterday and the symptoms returned..up and down idle, to the point where the engine stalls when in R or D.
So, after reading the newest club news letter, I figured I have a few MAP sensors, so I tried them ALL out. They are all 1 BAR GM MAP sensors, one of them supposedly new. Same issue with all of them. But here is the peculiar thing........when I disconnect the MAP (although I get a CES light), the engine runs great at about 1K RPMs. I put it in gear (D or R) and it drops to around 900 RPMs, but stable.
What the hell, over??
Any ideas?
\D
Post by: Fierofool on February 25, 2019, 05:45:28 pm
Post by: GTRS Fiero on February 25, 2019, 06:00:30 pm
The DIS ECU seems to handle a lack of MAP sensor input differently. The MAP sensor is for fueling, which means you have a fueling issue. Did you check for vacuum on the MAP sensor vacuum line?
Did you run the voltage tests in the newsletter? Since it is the same MAP sensor, the voltage tests should be the same.
The TPS, O2, and MAP sensors work together to help the ECU control fueling.
Oh. You'll probably need a scan tool to reset the code on your ECU.
Post by: Donster on February 26, 2019, 07:53:29 am
Vacuum checks out also.
Can't scan the 87-88 L4.
Have a new (refurbished) ECM on the way.
But I also read in Ogre's cave, that the fuel vapor canister can cause problems, so I'll be inspecting it tonight for cracks or other irregularities.
\D
Post by: GTRS Fiero on February 26, 2019, 08:02:19 am
Post by: Fierofool on February 26, 2019, 08:47:51 am
Post by: TopNotch on February 26, 2019, 11:14:53 am
Can't you insert a jumper in the A & B terminals of the ALDL and read the codes? To clear the codes, disconnect the ECM power supply at the battery, just like you would on a V6.Jumpering A-B does work on an 88 duke. Been there, done that.
Post by: Donster on February 26, 2019, 12:19:56 pm
Can't scan the 87-88 L4.
Post by: Donster on February 26, 2019, 12:21:37 pm
Now I really am hoping that it is the ECM.
Post by: GTRS Fiero on February 26, 2019, 06:15:34 pm
Can't you insert a jumper in the A & B terminals of the ALDL and read the codes? To clear the codes, disconnect the ECM power supply at the battery, just like you would on a V6.Jumpering A-B does work on an 88 duke. Been there, done that.
Were you able to scan your ECU? I know scanners exist. I think my brother has one.
Post by: Donster on February 27, 2019, 01:08:17 am
For the mean time a paper clip (I actuall have the Code Reader key from the NIFE Club) will just have to do.
Post by: GTRS Fiero on February 27, 2019, 08:00:44 am
Post by: Donster on February 27, 2019, 08:06:13 am
The reader will not reset the code.
I know. To do that, I always disconnect the battery.
\D
Post by: GTRS Fiero on February 27, 2019, 08:09:59 am
Post by: Donster on February 27, 2019, 08:15:56 am
I haven't found it yet, but supposedly, there is even a connector to disconnect only the ECM from power, eliminating the need to reprogramm all your radio stations. ;D
Post by: Fierofool on February 27, 2019, 12:21:27 pm
Post by: GTRS Fiero on February 27, 2019, 05:54:47 pm
Post by: Donster on March 02, 2019, 08:32:17 am
Still hunting idle when warm.
According to tracking no. the refurbished ECM is between the US and Germany now, so it shouldn't be long.
If that doesn't fix it, I'm getting rid of the Fiero and getting an old VW Carman Ghia. ;D
Post by: GTRS Fiero on March 02, 2019, 08:36:10 am
Post by: GTRS Fiero on March 08, 2019, 07:57:36 am
Post by: Donster on March 08, 2019, 11:50:05 am
Post by: GTRS Fiero on March 08, 2019, 05:41:30 pm
Post by: Donster on March 08, 2019, 11:46:57 pm
Post by: GTRS Fiero on March 09, 2019, 02:48:43 am
Post by: Donster on March 09, 2019, 09:30:34 am
Installed new (refurbished) ECM, new MAP.............. still hunting idle!!! >:( :-[
Here my question; can a faulty oil pressure switch cause idle problems? I know the fuel pump relies on information from the OPS.....and I also know that I accidentally shorted the OPS a while back, trying to connect it correctly again (Raydar told me I probably blew the fuel pump fuse, which was dead-on!), because the PO hacked around on the cables (only 1 cable connected to the OPS). I'm suspecting that something has been wrong with the OPS from the beginning. The PO also installed an 87 OPS instead of an 88 OPS, which I have, plus the 88 connector.
So while watching my instruments, I notice the fuel pressure takes a dip, then right after that, my idle takes a dip. It almost sounds like not enough fuel when the idle dips.
Does what I am explaining here make sense? Could it be related? If the moon is in the seventh house and the wind is blowing just right?
Frustrated in Germany and still old and grey...........Don
Post by: Fierofool on March 09, 2019, 09:55:39 am
Look on the side just below the fuel pressure regulator and just to the left side of the IAC to see if the cap for the idle stop screw has been removed. It may be that it's been tampered with since you're finding so many other things the OP 'tweaked'.
Post by: Donster on March 09, 2019, 10:11:01 am
I've read about the idle stop screw, but I doubt that messing with it could cause my problems just like messing with it could also not eliminate my problems. I have read that screwing around with that screw can actually make things worse, hence the factory seal to prevent knuckle-heads like me from messing with it. ;D
I just have a hunch that there has probably always been an issue with the OPS and the PO couldn't figure it out so he, as you put it, "tweaked" the wiring and thereby messed things up even more. And why put in an 87 OPS, if you have an 88 OPS lying around?? Just a guess, but I'm starting to get desperate now.
\D
Post by: Fierofool on March 09, 2019, 10:23:17 am
Post by: GTRS Fiero on March 09, 2019, 04:13:34 pm
Post by: TopNotch on March 09, 2019, 05:26:24 pm
Post by: Fierofool on March 09, 2019, 05:51:42 pm
Somehow, I thought this was an L4. Excuse my ignorance, but does the L4 have an idle adjustment screw?
They do. It's used to set the opening of the throttle body butterfly valve on both L4 and V6. A wire-type feeler gauge is inserted into the space between the lip of the butterfly valve and the side of the throttle body to set clearance.
The adjustment screw isn't a metering needle, but a detent against the butterfly. Like the old throttle set screws on carbureted engines.
Post by: GTRS Fiero on March 10, 2019, 12:24:16 am
I also know that voltage can affect idle. I have not gotten far in my research.
Here is a thought: the 2nd IAC seemed to fix things, for a bit. Is it possible that the problem is the IAC, but something happens to the IAC, and then the symptoms return? That would indicate either a wiring issue, or a lot of buildup causing the IAC not to function. Not knowing the plumbing, I don't know how that would play out. It would be easy to pull the IAC to check. Probably the passages should be cleaned, if they have not been.
Post by: Donster on March 11, 2019, 02:32:56 am
For the first time I got a 34 (MAP sensor) on 2 MAP sensors, plus the injector I just got is leaking.
Took a MAP off of an Opel, code went away.
Just an FYI: Pulling the battery DOES clear the codes on an 88 L4 ECM.
I did however notice that the PO didn't have a gasket (in addition to the O-ring) on the IAC valve. I found this out by looking at the pictures in the manual for the 87-88 700 TB.
I'll be putting one on today, as that actuall would make sense that it is sucking air around the IAC and causing idle issues when warm, as the IAC doesn't kick in until the engine is warm and comes out of closed loop.
The new IAC only came with an O-ring and I never thought of checking if any other gasket is needed.........so shame on me!
I'll update.
\D
Post by: Raydar on March 11, 2019, 05:10:51 pm
OK, turns out that now with the new ECM I'm getting error codes.
For the first time I got a 34 (MAP sensor) on 2 MAP sensors, plus the injector I just got is leaking.
Did you retain your same PROM? If not, what is the broadcast code on the chip in the new ECM?
Post by: Donster on March 12, 2019, 02:10:18 am
OK, turns out that now with the new ECM I'm getting error codes.
For the first time I got a 34 (MAP sensor) on 2 MAP sensors, plus the injector I just got is leaking.
Did you retain your same PROM? If not, what is the broadcast code on the chip in the new ECM?
Don't know the numbers on the PROM or ECM by heart, as I'm at work at the moment, but I know it was from an 88 Duke automatic with A/C without cruise, so it is the correct one for the car, don't know if the other one was correct though.
\D
Post by: Raydar on March 12, 2019, 11:50:29 am
I'll mention that one of the guys on the FB group has an Indy that (apparently) had a hunting idle. He mentioned, in passing, that the installation of the exhaust system from his 85 GT seemed to have fixed the hunting. Said it sounded better, too.
Post by: GTRS Fiero on March 12, 2019, 05:45:38 pm
Post by: Raydar on March 12, 2019, 08:51:27 pm
Was the exhaust clogged, or something?
Seems like it, but I'm not sure.
This was a car that he wants to leave stock/original, so I can't see him changing out something, just to be changing it.
Post by: Donster on March 14, 2019, 11:50:35 am
Look on the side just below the fuel pressure regulator and just to the left side of the IAC to see if the cap for the idle stop screw has been removed. It may be that it's been tampered with since you're finding so many other things the OP 'tweaked'.Cap had been removed, so I figured, how much more damage can I do if I screw with the screw? LOL
I tried resetting the IAC valve using the procedures I found on PFF and in the manual.
But after taking it out of diagnostic mode with the IAC unplugged, the engine will not start, so I cannot adjust the idle air screw. Is this an indication of a bad IAC?
If I plug the IAC back in, engine starts, but of course with the symptoms again once it runs warm.
And yes, I disconnected the battery, reconnected it, drove for about 60 KM at 35 mph and more, with stop & go and full stops with engine off in between.
That Karmann Ghia is looking better and better! ;D
Post by: GTRS Fiero on March 14, 2019, 06:34:24 pm
Post by: Donster on March 16, 2019, 07:33:57 am
But after taking it out of diagnostic mode with the IAC unplugged, the engine will not start, so I cannot adjust the idle air screw. Is this an indication of a bad IAC?
\D
Post by: GTRS Fiero on March 16, 2019, 08:55:11 am
Sorry, my IAC article is not ready, yet. I only have a few notes, and the article is at least 2 months out.
Get me a picture of that idle screw, please.
Post by: Donster on March 22, 2019, 12:38:55 pm
Still waiting on my new IAC so I can install and try to adjust the idle air control screw.
The German Karmann Ghia Convertible Club would love to have me as a new member! ;D
Post by: TopNotch on March 22, 2019, 01:13:26 pm
Post by: Donster on March 30, 2019, 10:08:58 am
Have you considered a throttle body rebuild? Replace all gaskets, O-rings, and anything not metal in the throttle body. You can get rebuild kits at auto parts stores over on this side of the pond.
$38.00 with express shipping.
OK, TBI rebuilt, new IAC (I think it is now the 3rd).
I have gone through all my cables, looking for a bad ground, and have replaced about everything that can be replaced..........see here:
EGR
MAP
MAT
O2 sensor
IAC
TPS
CTS
PCV
Injector
ALL TB gaskets & O-rings (cleaned entire TB housing)
Fuel pressure regulator
ECM
Ground cables
Still hunting when warm/hot. Sometimes also stalls.
What I have not yet replaced are the 2 ignition coils...........could they be at fault?
Right now I'm at a point where I am willing to replace just about anything, as I am getting a bit POed, to say the least.
Post by: Fierofool on March 30, 2019, 10:20:24 am
Post by: TopNotch on March 30, 2019, 11:53:35 am
Post by: Donster on March 30, 2019, 01:35:43 pm
If it's any consolation, I had the periodic problem with the 88 Duke Coupe. Sometimes it would idle without wavering, though at about 1500, and other times it would be up and down with a periodic stall. If my memory is working, I seem to remember that Pat's 88 has a very high idle, too.
And, did you get it fixed?
Post by: Donster on March 30, 2019, 01:37:07 pm
What I have not yet replaced are the 2 ignition coils...........could they be at fault?
Post by: Fierofool on March 30, 2019, 02:05:23 pm
Post by: TopNotch on March 30, 2019, 03:25:42 pm
What I have not yet replaced are the 2 ignition coils...........could they be at fault?Usually if a coil is bad, the engine will miss or die at the most inappropriate time. It will be worse when accelerating. Been there, done that.
Post by: GTRS Fiero on March 30, 2019, 09:07:50 pm
What happens if you unplug the IAC, and operate the throttle manually to keep the engine tunning? You should be able to do so, and keep a fairly steady RPM. Or, try to keep a steady RPM with your foot.
Post by: Donster on April 02, 2019, 04:27:22 am
What happens if you unplug the IAC, and operate the throttle manually to keep the engine tunning? You should be able to do so, and keep a fairly steady RPM. Or, try to keep a steady RPM with your foot.
If I disconnect the IAC, it stalls most of the time. When it doesn't stall, the idle still hunts.
Post by: Donster on April 02, 2019, 04:33:34 am
I've taken apart the C500 next to the battery and redone all of the wires.
Perhaps someone here can point me in the direction of possible bad wires/ground? Or are there too many?
Wich are the ground wires that could have such an effect on the idle?
I ordered a scan and diagnostic kit for the 87-88 Duke yesterday, what exactly, when I scan, should I look for?
\D
Post by: GTRS Fiero on April 02, 2019, 08:04:12 am
Separately, you could use a meter to check the resistance from the negative battery terminal to the engine block, to the transmission, to the O2 sensor, etc. Also, check the ground to the ECU.
Post by: Raydar on April 02, 2019, 09:22:40 am
I believe the Ogre even mentioned the upgrades on his page. I wouldn't be surprised if the hunting idle was one of those issues.
With that said, I don't know how one would go about researching TSBs for those upgrades, but I would suspect they're out there.
Post by: Donster on April 02, 2019, 01:02:14 pm
Post by: TopNotch on April 02, 2019, 02:14:34 pm
Post by: Donster on April 02, 2019, 03:31:53 pm
If I could find a blank, and one of those obsolete programmers that we used to use at work, I could copy my PROM. My duke idles perfectly. But I don't remember if your car is automatic or stick.Automatic
Post by: Raydar on April 02, 2019, 04:20:56 pm
If I could find a blank, and one of those obsolete programmers that we used to use at work, I could copy my PROM. My duke idles perfectly. But I don't remember if your car is automatic or stick.
I have both a blank PROM and a programmer. And my car also idles perfectly. But mine is also a manual. Anybody have a line on the "newest" automatic 87-88 Duke BIN file?
Post by: Fierofool on April 02, 2019, 05:45:19 pm
Post by: Raydar on April 02, 2019, 08:47:26 pm
You'll need to remove the two screws from the cover, and read the code from the label on the chip. (It may be different from the label on the outside of the ECM, if stuff has been swapped around.)
FWIW, the one that I have is "ACMH" (for a manual trans).
I think there is a table of Fiero broadcast codes, here, on the forum.
Edit - Here it is. http://gafiero.org/ECMgood/fieroprom.html
Holy schnickies! There are 8 different revisions of just the 87-88 automatic Duke PROM.
Post by: Donster on April 03, 2019, 12:56:28 am
I checked the Ogre's cave and compared it a few weeks ago, and I think this is the new/updated PROM I would need, if that helps:
Mine:
PROM ID: ALWN 6770
ECM: 1227748
Needed:
16143459
PROM ID:ATCA 3571
(as of 8/11) http://gafiero.org/ogre/promtsb.htm (http://gafiero.org/ogre/promtsb.htm)
This PROM was specifically for the "intermittent high idle" problem.
But I'll check to make sure.
Thanks.
Post by: Fierofool on April 03, 2019, 09:22:22 am
Post by: GTRS Fiero on April 03, 2019, 06:04:38 pm
Post by: Donster on April 04, 2019, 12:33:48 am
Do I read that chart correctly that it requires a new chip, a specific fuel sending unit, a specific fuel pump with a specific rubber bumper on the bottom of the pump and a specific pulsator on the fuel pump in order to overcome the issue?
That is only if you need to repair Hard Hot Engine Restart, for the idle issue, it is only the PROM.
Post by: Donster on April 05, 2019, 08:42:00 am
PROM: Delco ALWM 6770
ECM: 01227748 (Refurbished)
Post by: Donster on April 05, 2019, 04:19:01 pm
Could this be my issue??
Post by: GTRS Fiero on April 05, 2019, 04:48:06 pm
Post by: Donster on April 07, 2019, 08:37:00 am
Went at the C500 connector again, replaced positive cable from battery to underneath C500 block, replaced negative cable to engine, replaced ground cable from engine to chassis, sanded all surfaces.
No change, idle still hunting. Scanner / diagnostic kit won't arrive until sometime next week. Had fun troubleshooting in the beginning, sort of a challenge.
Now frustration is setting in. >:(
\D
Post by: GTRS Fiero on April 07, 2019, 12:16:29 pm
Post by: Donster on April 07, 2019, 03:00:18 pm
Did you replace the screw to the TBI?The only way to do that would be to take out the entire TBI, put it on a bench and drill out the torn off screw, then cut new threads.
Instead, I got another angle-iron and fastened it to a hole with threads in the TBI right next to the torn off screw and to the alternator.
Unfortunately, it didn't seem to be the cause of my idle issue. :(
Post by: Donster on April 08, 2019, 05:17:39 am
I have a heavy gauge wire that goes from the (-) battery to the engine block (good shape).
Then I have one that goes from the engine to the decklid frame (good shape).
But shouldn't there also be one directly from the (-) battery to the body/frame??
I don't have that. Where would/should it be connected to the frame?
Post by: Fierofool on April 08, 2019, 08:14:53 am
Post by: TopNotch on April 08, 2019, 10:27:36 am
But shouldn't there also be one directly from the (-) battery to the body/frame??You should definitely run a ground from the battery negative to the body. Who knows, it might even fix your idle problem.
I don't have that. Where would/should it be connected to the frame?
Post by: Donster on April 09, 2019, 08:31:34 am
The V6 Negative cable has a secondary ground wire that attaches to the battery tray, down toward the shock tower. Maybe the L4 has the same setup. I have a new ground cable that I think is for the Duke, and it has the same ground wire as a V6 cable.Replied on PFF........thnx
Post by: GTRS Fiero on April 11, 2019, 08:58:29 pm
Post by: Donster on April 12, 2019, 12:29:41 am
Post by: Donster on April 14, 2019, 08:17:13 am
Seems almost perfect now, except for a slight stutter/drop in the idle every now and then.
I'm still waiting on the scanner, but I am obviously on the right track here.
As usual, I will update here every time I do something.
\D
Post by: GTRS Fiero on April 15, 2019, 10:23:14 pm
I did an article on sensors and locations for the V6, since that is what I have, but maybe should do one for the L4. Much more difficult, though.
It would certainly help those unfortunate L4 owners. ;D
\D
I have to rely on people with an L4 to provide pictures/info.
Post by: GTRS Fiero on April 15, 2019, 10:25:28 pm
I think I figured it out. It's voltage to the ECU. Either a bad power, or a bad ground.
Interesting how that worked out.
Post by: GTRS Fiero on April 15, 2019, 10:26:46 pm
This is for the V6, but should be similar.
Have you ever checked their ECM supply voltage to see if it is changing? Some people have reported that adding ground wires have help their idle.
In the ECM prom there is actually a section that controls idle speed depending on battery supply voltage.
If the voltage dropps to 8 volts, the idle speed would be adjusted to 1200 rpm. At 14.4v it drops back to 900 rpm.
Here is a table:
Volts Idle
8.0 1000
9.6 1000
11.2 900
12.8 900
14.4 900
If the power to the ECM changes you could get into an loop where voltage drops, idle is increased, voltage comes up, idle is decreased. Sound familiar?
Try a battery charger to see what happens. Maybe have the voltage regulator in the alternator tested.
Maybe feed a stable 12V to the ECM.
Put a Volt meter on the power to the ECM.
The question was sortof answered.
Post by: Raydar on April 15, 2019, 10:38:18 pm
OK, the more ground / earth connections I replace or clean up (stainless steel bolts & nuts, grind to bare metal, new weaved copper or stainless steel ground cables), the better the car runs. ;D
Seems almost perfect now, except for a slight stutter/drop in the idle every now and then.
I'm still waiting on the scanner, but I am obviously on the right track here.
As usual, I will update here every time I do something.
\D
Interesting...
Now that you mention this, I seem to remember the "hunting idle" issue associated with using the disk-type injectors with the V6 Fiero ECM (3.4 swaps being the major culprit), being blamed on voltage fluctuations.
You might be on to something.
BTW... In every Fiero I've ever seen, there was a lighter weight pigtail coming off of the negative battery terminal, that is screwed into the frame, near the passenger side shock tower.
Since you have a large ground going from the battery to the block, and a strap going from the block to the hinge box on the frame, I wouldn't have thought this would be an issue, but stranger things have happened.
Edit - 87s and 88s have a built in stutter to the idle. Almost sounds like a random skip, several times a minute. It's quite normal (and has been commented on, before, elsewhere.)
Post by: Fierofool on April 15, 2019, 11:09:08 pm
Edit - 87s and 88s have a built in stutter to the idle. Almost sounds like a random skip, several times a minute. It's quite normal (and has been commented on, before, elsewhere.)
That's interesting. My 87 does it. I don't recall noticing it until the 3.4 swap. I always assumed it was one of the injectors causing what sounds like a slight miss at idle. Of course, that wouldn't be the case in the Duke, having just 1 injector.
That pigtail ground is also very close to the ground that's on the outside of the frame rail. It can be found by removing the right rear fenderwell liner. It has been thought to be a major problem when the ground is poor. It's a black insulated wire so it probably comes out of a harness, unlike the braided grounds.
Post by: Donster on April 16, 2019, 12:32:14 am
That pigtail ground is also very close to the ground that's on the outside of the frame rail. It can be found by removing the right rear fenderwell liner. It has been thought to be a major problem when the ground is poor. It's a black insulated wire so it probably comes out of a harness, unlike the braided grounds.That will be the next thing I check. Might as well, as I have done just about and replaced everything else. ;D
I'll update any changes, improvements.
\D
Post by: Donster on April 16, 2019, 12:40:53 am
I think I figured it out. It's voltage to the ECU. Either a bad power, or a bad ground.
Interesting how that worked out.
True statement Mike.
But after so many recommendations, I had to proceed systematically, especially not having a scanner.
Checking all the grounds would have been cheaper and faster, but in the beginning, the majority of recommendations suggested one of the sensors, so that is where I started my hunt.
Thnx!
\D
Post by: GTRS Fiero on April 16, 2019, 07:24:37 pm
Post by: Donster on April 17, 2019, 04:43:30 am
That pigtail ground is also very close to the ground that's on the outside of the frame rail. It can be found by removing the right rear fenderwell liner. It has been thought to be a major problem when the ground is poor. It's a black insulated wire so it probably comes out of a harness, unlike the braided grounds.
Could somebody please check the SM and let me know, exactly where this ground connection is?
Thanks.
\D
Post by: Fierofool on April 17, 2019, 07:58:58 am
I've done a search and have found pictures of rusted 87 and 88 frame rails but didn't see the ground wire. I know I've seen pictures of the wire bolted to the upper frame rail. I know you're getting some ground information from The Ogre. Maybe he has a picture. Or try Patrick. He seems to have a good library.
Post by: Donster on April 19, 2019, 04:42:04 am
Anyone know where it was supposed to come from? I'm assuming from the C500, inside the harness going to the passenger side rear lights?
\D
Post by: Fierofool on April 19, 2019, 08:29:59 am
Just a suggestion for a solution. While you have the fenderwell liner out, maybe install one there. If they're available in Germany, secure one of those long post battery terminals, of the type that can be used to connect 2 batteries together. Make your own heavy ground strap or purchase a good one and mount it to the frame rail. The only unknown is from where the factory ground emanates. What does it tie to the frame rail?
Post by: Donster on April 19, 2019, 05:28:20 pm
Post by: Fierofool on April 19, 2019, 06:03:52 pm
Post by: TopNotch on April 19, 2019, 08:17:18 pm
Post by: GTRS Fiero on April 19, 2019, 09:40:21 pm
Post by: TopNotch on April 20, 2019, 05:37:12 pm
Post by: GTRS Fiero on April 20, 2019, 05:42:58 pm
Post by: Donster on April 25, 2019, 11:50:07 am
Thought I had figured out TunerPro RT with the $48 definition file, but I don't trust myself and obviously, some of the readings don't make sense. I measured voltage with a DVM directly at the terminals and had 13.6 V!
Perhaps some of you can tell me what I am doing wrong.
Here is a screen-shot of the ALDL dash and the ALDL flags.
I also have the CSV file.
BTW-Idle is still hunting, matter of fact, getting worse..........thought I had it. :-[
HELP!
Post by: TopNotch on April 25, 2019, 10:11:50 pm
You'll probably need twp people to make these readings.
Post by: Donster on April 26, 2019, 02:21:33 am
Can somebody provide me with a wiring diagram, as I don't have a shop manual for the 88. :(
Thanks.
Post by: Donster on April 29, 2019, 01:21:30 am
Can somebody provide me with a wiring diagram, as I don't have a shop manual for the 88. :(
Anyone?
Or does someone have an 88 SM for sale? 87 SM here in Germany was sold before I had a chance to buy it.
On the ECM connectors I found the following:
Had a steady 12 V on W(hite)10 & 15 (battery and ECM fuse), although scan tool told me only 9.6 V???
Had a good ground on W(hite) 12 & 13 (system ground).
Had no ground on B(lack)12 (sensor ground for TPS & CTS) and on W(hite)14 (sensor ground for MAP & MAT), so I added ground by splicing in two wires to the harness and to the chassis, just for troubleshooting purposes. Peculiar though, I had ground, when measured directly at those aforementioned 4 sensors, so I assumed, I had broken wires somewhere in the harness???
Made no difference in the hunting idle, but feels like the car is running worse now.
Is ground on those two connections only provided when ECM is running (ignition "ON")?
Guess I need not mention that this is driving me insane now! :(
Thanks for ANY suggestions, especially if I did something wrong!
\D
Post by: Raydar on April 29, 2019, 05:36:44 am
On the ECM connectors I found the following:
Had a steady 12 V on W(hite)10 & 15 (battery and ECM fuse), although scan tool told me only 9.6 V???
Had a good ground on W(hite) 12 & 13 (system ground).
Had no ground on B(lack)12 (sensor ground for TPS & CTS) and on W(hite)14 (sensor ground for MAP & MAT), so I added ground by splicing in two wires to the harness and to the chassis, just for troubleshooting purposes. Peculiar though, I had ground, when measured directly at those aforementioned 4 sensors, so I assumed, I had broken wires somewhere in the harness???
Made no difference in the hunting idle, but feels like the car is running worse now.
Is ground on those two connections only provided when ECM is running (ignition "ON")?
Guess I need not mention that this is driving me insane now! :(
Thanks for ANY suggestions, especially if I did something wrong!
\D
That's quite possibly just a "logic ground" or "logic common". Not necessarily "earth ground" or "chassis ground". If it made other things worse, I would be inclined to undo it.
I've got an 88 manual. Let me see if I can get a workable copy of the diagram.
Edit - you said you had ground at the sensors, so I'm confused, now.
BTW... the pic of your ALDL data is suspect. All the temperatures seemed to be wrong, as well as the DC voltage(s). Makes me wonder if it's really configured (or written) correctly.
I still don't have my car here, or I'd record my values.
Post by: Donster on April 29, 2019, 06:30:43 am
That's quite possibly just a "logic ground" or "logic common". Not necessarily "earth ground" or "chassis ground". If it made other things worse, I would be inclined to undo it.
I've got an 88 manual. Let me see if I can get a workable copy of the diagram.
Edit - you said you had ground at the sensors, so I'm confused, now.
Yes, that confused me also, which is why I'm assuming that perhaps there is a broken wire in the harness.
Then again, I might have been measuring at the wrong pins. I'ts like Russian Roulette without the correct shop manual, having to rely on .jpg's downloaded from the web. :-\
I'll most likely remove the additional grounds I have added and start over again.
BTW: Found an 88 SM on Ebay. Problem is, I ordered it from the US, so it will take a while to get here (appr. 3 weeks!!).
In case me engine harness is totally hosed, do you have an 88 Duke harness left over from any of your engine swaps? ;D
Thnx Steve,
\D
Post by: Raydar on April 29, 2019, 08:07:25 am
My current Duke has a manual trans, so that's not going to do you much good, anyway. Sorry.
With that said, it shouldn't be too long before I have the Fiero back here, so I can make some measurements. Have to clear out a bit of garage space.
Post by: Donster on April 29, 2019, 09:48:40 am
Thnx,
\D
Post by: Raydar on April 29, 2019, 10:16:29 am
Post by: Donster on April 29, 2019, 11:08:14 am
I've got one for TunerCat. I can email it to you tonight. Don't think it will work with TunerPro, though. I might be wrong.
Is that the same program as DataCat by C.A.T.S.? I have that.
Oooops......correction............my trial version has expired
Post by: Raydar on April 29, 2019, 11:58:54 am
But yeah... pretty sure it's the same thing.
But that's a programmer. NOT a scan tool.
Post by: Donster on April 29, 2019, 12:45:39 pm
If I could find a version older than DataCat v 1.1.2.722, that might work, but no luck so far.
But if you send me the def file, I'll give it a try anyways and would appreciate it nevertheless.
Thnx for all your time and replies-
\D
Post by: Raydar on April 29, 2019, 08:53:29 pm
It's installed on another computer.
Edit - Sorry. Got sidetracked this evening. Didn't get to dig up anything that I wanted to.
Post by: Donster on April 30, 2019, 12:34:34 am
Post by: Donster on April 30, 2019, 12:37:30 am
But that's a programmer. NOT a scan tool.
But it will enable me to at least read data, no?
What do people with an 88 Duke (DIS) use to scan? Obviously, WinALDL won't work. :-\
Post by: Donster on April 30, 2019, 01:56:16 am
I've got an 88 manual. Let me see if I can get a workable copy of the diagram.
No worries Steve, got the diagram for the 88 Duke, thanks anyways.
\D
Post by: Raydar on April 30, 2019, 07:58:28 am
But that's a programmer. NOT a scan tool.
But it will enable me to at least read data, no?
What do people with an 88 Duke (DIS) use to scan? Obviously, WinALDL won't work. :-\
Nope. All it will do is decode and edit EPROMs. There is a separate program used to read and burn them, that is included in the "package".
What you need is an OBD1 scan tool. (NOT just a code reader.) They're kind of uncommon, now. But the ones that are out there are not terribly expensive.
I've got an AutoXray 6000. Does OBD1 and OBD2. Don't recall if I've ever used it to scan my Duke, but there really isn't any reason that it shouldn't. It scans everything else, and provides sensor readings and etc. (The display says that it goes up to 2005, but I've read much newer cars with no problem.)
Works like WinALDL, only it's self-contained. Has its own display. Doesn't need a laptop.
If you buy an AutoXray, be aware that they are out of business. Nobody is around to support them. You'll have to buy all your cables and stuff off of eBay, if you don't get them with whatever you buy.
Actron is another "consumer" brand of scan tool.
You might find an old GM Tech1 scan tool, but they might need a lot of expensive modules to make them work. (Not sure, on this point.)
Edit - I was poking around and saw a bluetooth device that supports OBD1 and an android phone or computer, including TunerPro. It has a selectable ALDL baud rate. 160 baud or 8192 baud.
It occured to me that you might be using a similar device. The baud rate of the 88 (and 87) Duke must be set to 8192. They're the only Fiero ECMs that use that baud rate.
If the baud rate is wrong, it could cause bizarre readings, such as what I was seeing on your "dashboard" display. ("negative" temperature readings, etc.)
Post by: Donster on April 30, 2019, 08:35:04 am
My cable actually has a selector switch for baud rates. It can do 160 AND 8192 baud.
I also have ALDL_Test, wich lets me select comm ports and baud rate. It checks out.
This is what I bought:
https://www.ebay.de/itm/Diagnose-Corvette-C4-Camaro-Firebird-VAN-FIERO-FIERO-Truck-Caprice-Transport-TPI/254207006495?hash=item3b2feb171f:g:3QIAAOSwsixcjPkl
I am just wondering if the def file for the 88 Duke is correct. A file name can be changed easily. Once I load it into TunerPro, it tells me it is for a 1991 vehicle??
I've downloaded a $48 file from the internet (source can't remeber), but funny thing is, it also tells me it is for a 1991 vehicle, with a 2.2 liter engine.
Post by: Raydar on April 30, 2019, 12:30:56 pm
$48 supports 87 - 88 Pontiac Fiero 2.5L 4 Cyl. LR8,
87 Grand Am 2.5L 4 Cyl. L68,
87 - 90 Celebrity, 6000, Cutlass, Ciera, Century 2.5L 4 Cyl. LR8.
A 2.2 is not mentioned.
$70 supports a 90 - 91 Cavalier, Sunbird LM3 2.2L
ECM is 1227748 in both cases.
What is the file extension for your $48 ? I can look around.
Thinking about it, I'm not sure my TunerCat file will work, though. Since we're doing different things.
Post by: Raydar on April 30, 2019, 12:35:25 pm
http://www.gearhead-efi.com/Fuel-Injection/showthread.php?2981-1227748-ECM-Information-48
Post by: Donster on May 03, 2019, 11:34:07 am
Post by: Raydar on May 03, 2019, 12:55:48 pm
The purple lead is the "start" wire. It will have 12 VDC on it (to pull in the starter Bendix) when you turn the key to start.
If you trace it, it should go to the P/N switch on the trans. It should continue out of the P/N switch as a yellow wire.
Some cars with trunk poppers have a goofy "interlock circuit" that finds ground through that wire, and the starter solenoid. (Strange setup.)
Is it loose? Is the terminal on the solenoid loose?
Post by: Fierofool on May 03, 2019, 01:45:25 pm
On other starters I have twisted that screw's connection off inside the solenoid when the bottom jam nut was loose.
Post by: Donster on May 03, 2019, 03:41:51 pm
Can somebody tell me what the second cable to the starter is? It is the thinner one, not the cable from theOf course I meant the POSITIVE terminal.negativepositive battery terminal.
Post by: Donster on May 03, 2019, 03:45:40 pm
Don, does that extra wire go into a factory wire sheath, or is it free-floating on it's own? Sounds like they're feeding something off it that they only want to operate while the ignition is ON.Tomorrow I'll have the car up on a lift, so I'll be able to see more. I know the cable disappears into a harness, but I can't tell if the connector or solenoid is loose.
Post by: Donster on May 04, 2019, 07:15:47 am
I also figured out that there will only be ground on BLACK12 & WHITE14 if the ECM is plugged in and gets ground on WHITE 12 & 13. (Brain Fart!)
All grounds and voltages on the ECM check out. Hence the confusion earlier; I measured ground at the sensors with the ECM plugged in, so I had ground. Disconnected the ECM and had no ground.................D'uH!
I think I've asked this before; does a bad MAP "always" throw a code?? If I disconnect the MAP cables (not the vacuum), the car idles fine and stable. Unfortunately, it lights up the Check Wallet light and sets code 33 or 34. I plug it back in, the hunting idle returns, but no codes. :o
Post by: Donster on May 04, 2019, 07:45:50 am
According to TunerCat,
$48 supports 87 - 88 Pontiac Fiero 2.5L 4 Cyl. LR8,
87 Grand Am 2.5L 4 Cyl. L68,
87 - 90 Celebrity, 6000, Cutlass, Ciera, Century 2.5L 4 Cyl. LR8.
A 2.2 is not mentioned.
$70 supports a 90 - 91 Cavalier, Sunbird LM3 2.2L
ECM is 1227748 in both cases.
What is the file extension for your $48 ? I can look around.
Thinking about it, I'm not sure my TunerCat file will work, though. Since we're doing different things.
As soon as I load the "so called" $48 file it shows up as:
Fie extension is .xdfAnd when I try to download it from the web, I get a message that my IP is outside the US and I can't continue.Can somebody get the $48 file for me? Please? Pretty Please? ;D
Post by: TopNotch on May 04, 2019, 09:44:24 am
Post by: Raydar on May 04, 2019, 10:42:06 am
As soon as I load the "so called" $48 file it shows up as:
Fie extension is .xdf And when I try to download it from the web, I get a message that my IP is outside the US and I can't continue.Can somebody get the $48 file for me? Please? Pretty Please? ;D
That is clearly the wrong file.
Looks like Pat has got you covered on the correct one. If not, I'll see what I can come up with.
I can believe that a bad map can cause issues without throwing a code. It's just a pressure transducer.
Post by: Fierofool on May 04, 2019, 12:41:01 pm
Post by: Donster on May 04, 2019, 01:30:40 pm
I uploaded the file to http://gafiero.org/files/$48.xdf (http://gafiero.org/files/$48.xdf)Awesome! Thanks Pat.
But how do I convert it to an .ads file for TunerPro?
Post by: TopNotch on May 04, 2019, 02:08:02 pm
Post by: Donster on May 04, 2019, 02:14:38 pm
Post by: Raydar on May 04, 2019, 05:39:53 pm
Doesn't the MAP sensor also control the fuel pressure regulator, or are they just both connected to the same intake vacuum port?
On a V6, they're just connected to the same vacuum source. Not even sure about the Duke.
Post by: Donster on May 05, 2019, 12:47:19 pm
I think I've asked this before; does a bad MAP "always" throw a code?? If I disconnect the MAP cables (not the vacuum), the car idles fine and stable. Unfortunately, it lights up the Check Wallet light and sets code 33 or 34. I plug it back in, the hunting idle returns, but no codes. :o
Doesn't this sound like a bad MAP sensor??
Post by: GTRS Fiero on May 05, 2019, 12:48:56 pm
Post by: Donster on May 10, 2019, 03:56:46 am
Below are the scans from the warm engine, no trouble codes, what am I missing?
Thnx!
Post by: TopNotch on May 10, 2019, 08:12:46 am
Post by: Raydar on May 10, 2019, 08:23:03 am
I don't know exactly what the reading means. Could be 34 of 34 "steps" (which would seem to indicate that something is maxed out) or 34 steps one way, and 34 steps the other way. (34 is a strange number to be a maximum. I would expect 16, or 32, or 64... something like that. Just thinking out loud.)
For what it's worth, when the engine is cold, the O2 sensor reading should read a steady ~.445 volts. It should also show "not ready", I would think.
Once the engine is warmed up, the O2 sensor should bounce around between .1 volts and .7 volts. Probably too rapidly for you to even read it.
If it's just sitting at .106, the O2 is either lying, or the engine is running very lean. I notice the "Mix / lean" reading. I would think it should be bouncing around, too. But if the O2 is sitting at .106, the "lean" flag would be expected.
(I had an O2 sensor to fail, in that manner. Was reporting "full lean". In reality the ECM was just dumping fuel in. It was running so rich that it would burn my eyes when I stood behind the car.)
I wish Ron was checking in. He could provide some valuable insight.
Post by: Donster on May 10, 2019, 09:53:16 am
Hence, IAC was at 34 steps at engine start-up and at 34 when measured.
Post by: Donster on May 10, 2019, 09:56:09 am
I'd like to know where you got the scanner.
Home made by a member of the German Fiero club.
Kewl thing is, it gets its power via ALDL port while scanning OR via USB port, but also has batteries.
Post by: TopNotch on May 10, 2019, 10:52:02 am
[Home made by a member of the German Fiero club.Oliver Scholtz?
Post by: Donster on May 10, 2019, 11:14:44 am
Oliver Scholtz?
Who else? :D
This way I could be assured that it works. And it is very professional looking!
Post by: Donster on May 10, 2019, 11:24:13 am
Post by: Raydar on May 10, 2019, 02:23:44 pm
As awesome as it may be, it is worthless to me, if it won't help me narrow down my issue!
Pay attention to what the O2 sensor is doing, as posted above. It needs to be switching back and forth.
Assuming the scanner reports readings in real time.
Post by: Donster on May 11, 2019, 12:27:23 pm
Also was told, an incorrect thermostat can possibly cause hunting idle. Weird. :o
Post by: Fierofool on May 11, 2019, 04:38:35 pm
Post by: Donster on May 13, 2019, 09:27:37 am
It has become a common practice to drill a 1/8 hole in the flange if it doesn't already have a little weep valve pin in it. I don't remember why, but I pulled both of mine and did the mod.
Can somebody post a picture, of where exactly the little hole needs to be drilled?
Post by: Fierofool on May 13, 2019, 10:27:28 am
https://www.walmart.com/ip/Stant-45819-Superstat-Thermostat/138505932?wmlspartner=wlpa&selectedSellerId=0&adid=22222222227058081778&wl0=&wl1=g&wl2=c&wl3=338615277757&wl4=aud-566049426865:pla-529923070479&wl5=9010757&wl6=&wl7=&wl8=&wl9=pla&wl10=8175035&wl11=online&wl12=138505932&wl13=&veh=sem&gclid=EAIaIQobChMInbacstqY4gIVEtbACh1hDwgNEAQYBCABEgL2j_D_BwE
Post by: Raydar on May 13, 2019, 11:32:22 am
It has become a common practice to drill a 1/8 hole in the flange if it doesn't already have a little weep valve pin in it. I don't remember why, but I pulled both of mine and did the mod.
It just stops the thermostat from trapping air bubbles, which can keep it from opening properly. It also allows just a little bit of coolant to circulate, for the same reason.
Post by: Fierofool on May 13, 2019, 02:59:32 pm
But the air bubble issue was why I had heard people were doing it. I have seen some that have a hole already in them with a little copper or brass pin in the hole. I don't remember what vehicle they were for, though. Could have been a Ford or Grand Prix.
Post by: GTRS Fiero on May 13, 2019, 07:33:14 pm
Post by: Fierofool on May 13, 2019, 09:53:17 pm
Post by: Donster on May 14, 2019, 02:35:24 am
Post by: GTRS Fiero on May 14, 2019, 08:14:16 am
I don't know. I don't think so. Neither does it on the 87 or 88 V6.
That is the return line.
Post by: Fierofool on May 14, 2019, 08:49:27 am
Post by: Donster on May 15, 2019, 12:27:21 pm
I scanned again today, paying attention to what Steve posted regarding to O2 sensor. While it does move around, I'm sure it is not in the correct range. It was one of the first things I replaced when this issue first reared it's ugly head. Just to make sure, I installed the old one again, and it had "0", ZERO readings, then the new one (which I assumed is working) would go from 0.1V to 0.9V to 1.1V to 0.4V and never zero in on a particular value. Can't be right, can it?
So I disconnected the O2 sensor, and whaddayaknow? Engine runs fine, no stumble, no hunting, no idle dropping, no stalling.
Downside is, it will occasionally throw a code 13 (O2 open) and the scanner tells me the engine is running lean. Before, with either O2 sensors installed, it would bounce between lean & rich by the second.
Can we now safely say that it is either the O2 sensor or the (one, purple) wire, going to the ECM that is causing my issue???
BTW: The new O2 sensor was a BOSCH, which you would expect NOT to be bad out of the box.
Post by: Raydar on May 15, 2019, 02:11:00 pm
If it settles on one side or the the other of .445 volts, THAT'S a problem. Once it's warmed up, it should always switch around. (The only real exceptions are accel or decel.)
I have had Bosch sensors go bad "prematurely". Can't say that I've ever had a bad one, out of the box, though.
I've had good luck with NTK O2 sensors.
Post by: Donster on May 17, 2019, 05:38:34 am
And in the last 2 days, for some reason, the ECM does not throw a code, no CES light....AND more importantly, the engine is running as it should.
I will have to wait until I get a new O2 sensor to see if things return to normal. If not I obviously have an issue with the wiring in the O2 sensor circuit. Should not be to hard to fix, as it is only one wire (purple). No ground wire, as the sensor actually self-grounds to the header. And I don't need to ask for wire diagrams anymore, as I just got this in the mail: ;D
Brand new! $50.00 with $20.00 shipping from the US! In combination with my new scanner tool I'm ready for just about any problem this Duke throws at me (I know, I've always been an optimist ;D )
BTW, the scanner tool can be ordered (works on ALL Fieros and shows values in "REAL-TIME"!) as long as you are willing to endure the delivery time.
Post by: GTRS Fiero on May 17, 2019, 06:55:59 am
The scanner doesn't reset codes, though.
Post by: Donster on May 17, 2019, 07:15:13 am
Glad you got the book.
The scanner doesn't reset codes, though.
Nope, still need to do the manual "Disconnect" with the power to ECM cable next to the C500.
Can't have everything. ;D
Post by: Donster on May 25, 2019, 07:43:23 am
Doesn't overheat, runs stable, no hunting idle, good mileage, good acceleration.
So, what bad could happen not having the O2 sensor connected?
Post by: GTRS Fiero on May 25, 2019, 08:03:42 am
Post by: Fierofool on May 25, 2019, 08:36:49 am
They say that with the o2 disconnected the ECM reverts to using the base fuel maps and might run a little richer. When the car is warmed up does the exhaust smell sting your nose or eyes?
Post by: Donster on May 25, 2019, 09:22:37 am
When the car is warmed up does the exhaust smell sting your nose or eyes?
Can't say it does. We are about to take the car on a 60 mile round trip. I'll sniff when we get back. ;D
Post by: GTRS Fiero on May 25, 2019, 06:58:18 pm
Post by: Raydar on May 25, 2019, 08:11:14 pm
As I have not received the new O2 sensor yet, we have been running the car with the sensor disconnected and I must say the engine is running great without.
Doesn't overheat, runs stable, no hunting idle, good mileage, good acceleration.
So, what bad could happen not having the O2 sensor connected?
With the sensor disconnected, the ECM will "plug in" a nominal value. My 4.9 is .445 volts, IIRC. If yours shows .42 volts, then that's what the ECM is plugging in.
Come to think of it, for a long time, "European spec" American cars operated in "open loop" - i.e. without an oxygen sensor - by design. (The ECMs were programmed to run without it.)
This had to do with the unavailability of unleaded gas. The lead would clog up the O2 sensors and the catalysts.
Heck... if it works, run with it.
Odd that it's not setting a code / turning on the light, though. That would lead me to believe there's something wonky with the wiring.
Post by: GTRS Fiero on May 25, 2019, 08:16:51 pm
Post by: Donster on May 27, 2019, 08:07:01 am
Need to get the headliner fixed, A/C, install power windows and the paint job.
If it keeps running the way it does right now, I'm not going to mess with it, albeit it does bother me, as it isn't the way it was meant to be.
Post by: Donster on May 30, 2019, 07:35:42 am
When the car is warmed up does the exhaust smell sting your nose or eyes?
Can't say it does. We are about to take the car on a 60 mile round trip. I'll sniff when we get back. ;D
No funny smells, however low oil pressure since yesterday. Can’t see how it would be related.
Post by: Fierofool on May 30, 2019, 07:44:49 am
Post by: Donster on May 31, 2019, 05:15:47 am
Darn thing is hard to get to, under the TB housing. Plus, the PO installed an 87 OPS. I have an 88 OPS, but can't figure out, how to get the 87 OPS out. Anybody know what size wrench to use on the 87. It is sort of hidden behind the plastic housing that is over the OPS.
Guess I should have removed it while the muffler was out....shame on me.
Thnx,
\D
Post by: Fierofool on May 31, 2019, 07:19:20 am
Post by: GTRS Fiero on May 31, 2019, 07:43:52 am
Post by: TopNotch on May 31, 2019, 09:57:02 am
85-87
88
Post by: Fierofool on May 31, 2019, 10:56:18 am
Post by: TopNotch on May 31, 2019, 11:29:49 am
Post by: GTRS Fiero on May 31, 2019, 05:12:44 pm
Wiring should be in the Feb2019 newsletter.
Post by: Fierofool on July 02, 2019, 07:11:07 pm
I don't know if the 88 Duke has a canister, but you might try disconnecting and plugging the two lines that go to the throttle body and intake to see if the idle calms down. Just a WAG.
Post by: TopNotch on July 02, 2019, 08:46:11 pm
Post by: Donster on July 03, 2019, 01:25:29 am
In our investigation of the Evap Canister operation, I found that both ports of the evap canister are attached to the intake and throttle body. If one of the lines between is cracked or if the canister purge valve is defective, this could result in a vacuum leak to the intake system.
I don't know if the 88 Duke has a canister, but you might try disconnecting and plugging the two lines that go to the throttle body and intake to see if the idle calms down. Just a WAG.
The vacuum lines to the canister were one of the first things I replaced. Also found out that the PO had a brainfart and swapped/reversed them. Can happen, as original lines were hard plastic and different sizes, but the ones he used were rubber/flexible and would fit on either connection. In cases like this, it is great to have an 88 Helms. ;D
Thnx!
Post by: Donster on July 08, 2019, 07:03:43 am
Post by: GTRS Fiero on July 08, 2019, 08:13:05 am
Post by: Donster on July 09, 2019, 01:00:48 am
BTW: New pod with circuit membrane arrived, all instruments working again, just need to place the fuel gauge needle again. It shows sooooo full, there should be 30 gallons of fuel in it. LOL
Post by: GTRS Fiero on July 09, 2019, 07:41:52 am
Post by: Donster on July 13, 2019, 09:50:49 am
Post by: Donster on July 14, 2019, 09:58:08 am
The ONLY part I have yet to replace is the fuel pump, although the fuel pressure seems to be OK, but at high temps, the pump may be functioning intermittently.
Very discouraged at the moment.
Post by: GTRS Fiero on July 14, 2019, 10:07:54 am
Post by: Donster on July 14, 2019, 10:19:26 am
I did notice that the heat shield was missing on the ICM when I replaced the coils. It seems to be impossible to get, so I made one myself from coke cans (made mine 3 layers).
Post by: GTRS Fiero on July 14, 2019, 10:21:09 am
Post by: TopNotch on July 14, 2019, 11:55:20 am
AC DelcoIf you're talking about the flat metal piece between the ICM and the coils, it needs to be made of steel. It is a magnetic shield. If you have hardware stores over there that sell galvanized sheet metal, get some and make your shield out of two layers of that.
I did notice that the heat shield was missing on the ICM when I replaced the coils. It seems to be impossible to get, so I made one myself from coke cans (made mine 3 layers).
Post by: Donster on July 14, 2019, 12:40:56 pm
Post by: TopNotch on July 14, 2019, 03:25:36 pm
So what negative affects could the missing shield cause? Hunting idle perhaps?According to The Ogre (http://gafiero.org/ogre/gmdis.htm), a missing shield can cause code 42. I'm not sure what else, and I don't think I'll try running mine without it.
Post by: Donster on July 15, 2019, 10:40:50 am
Post by: TopNotch on July 15, 2019, 03:23:48 pm
Post by: Donster on July 15, 2019, 03:45:32 pm
Post by: TopNotch on July 15, 2019, 04:33:51 pm
Post by: Fierofool on July 15, 2019, 04:46:15 pm
In our irrigation pumps that we installed into wet wells, the impellers were brass and the shafts and couplings coming down from the motor were all of high quality non-magnetic stainless and even after 5 or more years of being submerged, they never showed any signs of oxidation. There are different names for the types of stainless but I don't remember what they were. Seems like there were 5 or 6 different qualities.
Post by: TopNotch on July 15, 2019, 05:07:02 pm
Post by: Fierofool on July 15, 2019, 05:59:17 pm
Post by: GTRS Fiero on July 15, 2019, 07:26:41 pm
Post by: Donster on July 18, 2019, 01:25:52 am
If not, I will take my spare ICM to a metal work shop and have them make one from 1 mm galvanized steel. Might have them make a couple, depending on cost.
Post by: Donster on August 02, 2019, 08:46:26 am
Time to get rid of it. :-[
Post by: TopNotch on August 02, 2019, 10:04:54 am
OK, shield arrived yesterday, installed today, ran the car hot. Stutters at low RPMs, idle still hunts. Stalls occasionally.Or re-engine it.
Time to get rid of it. :-[
Post by: Donster on August 02, 2019, 02:21:35 pm
OK, shield arrived yesterday, installed today, ran the car hot. Stutters at low RPMs, idle still hunts. Stalls occasionally.Or re-engine it.
Time to get rid of it. :-[
Not worth the trouble. I've already invested too much time and money in it.
Post by: GTRS Fiero on August 02, 2019, 06:36:10 pm
I made a point of meeting JohnWPB, because he has persisted despite all the myriad issues with his Fiero. While he is not necessarily a role model, I do respect what he has done in this regard.
When I was just a kid, there was an old man who ran a newspaper. He printed the truth, whatever the truth was. Every so often, a certain group of people would come destroy his office. The old man rebuilt, every time. Time and again, that old man was warned by others to not print certain things, to avoid having his office destroyed. The old man refused to change, not because he was old, but because he saw dishonesty as being the easy way. He said that there is no stopping someone who is right and keeps on coming. He was told to move to another town, but refused, because he said running never fixes anything. One night, things came to a head. The old man was in his 80's, and working late. The group of people had finally decided on a permanapent fix. The office was shot to doll rags, and the old man was hurt. I helped bury those people. The old man was beside me with a shovel. I asked him why. He said it was the right thing to do. Some years ago, that old man died in his office. His final paper had an article titled, "The Truth Shall Set You Free". If I could have found his gravestone, I'd have had that put on the stone. That old man never had anything, but never compromised, and I respect him highly.
Sometimes, I think back on defining moments. There are some I wish I could change, because I don't like to think that is who I am, but they are all a part of me. I often wish I had that old man's conviction and steadfast spirit.
Post by: Donster on August 19, 2019, 04:21:04 pm
I have the ATBW.bin file for an automatic. If I email you the file, can you burn a PROM for me?If I could find a blank, and one of those obsolete programmers that we used to use at work, I could copy my PROM. My duke idles perfectly. But I don't remember if your car is automatic or stick.
I have both a blank PROM and a programmer. And my car also idles perfectly. But mine is also a manual. Anybody have a line on the "newest" automatic 87-88 Duke BIN file?
Post by: Donster on March 31, 2020, 02:37:13 am
Our hunting idle issue is gone!!
Let me write it one more time.....
OUR HUNTING IDLE ISSUE IS GONE! ;D ;D ;D
Post by: Raydar on March 31, 2020, 07:32:09 am
Post by: Fierofool on March 31, 2020, 08:18:37 am
Post by: Donster on March 31, 2020, 08:28:06 am
Wait... what? What was the fix?
There's this guy in Germany called Oliver. ;D Should have thought of him before I burdened you.
Amazing what an updated chip can do. Have no idea what was wrong with the one you sent me, just had Oliver burn a new one for me with the .bin file.
It might have been the chip itself, nobody knows.
You sold the car!?Au contraire....... Anne really loves the little Pearl now, now that it is fun to drive again. ;D
Post by: Raydar on March 31, 2020, 08:36:22 am
There's this guy in Germany called Oliver. ;D Should have thought of him before I burdened you.
Amazing what an updated chip can do. Have no idea what was wrong with the one you sent me, just had Oliver burn a new one for me with the .bin file.
It might have been the chip itself, nobody knows.
I know of Oliver. I'm happy that he was able to fix you up. If you care to, send my chip to him and let him read it. See what went wrong. (I did re-read it to make sure the program "took". It annoys me as much as it annoys you, that I sent you a bad chip.)
Glad that was the fix.
Post by: GTRS Fiero on March 31, 2020, 05:30:45 pm
Au contraire....... Anne really loves the little Pearl now, now that it is fun to drive again. ;D
Glad things are sorted. Enjoy!