Engine stalls when cold

[GTRS Fiero]

Is it possible that a cam could cause tip-in throttle issues when the engine is cold?

My Fiero runs great, once warmed up, but likes to die on tip-in when cold.  Once it's opened up, it runs great.  It's just from a stop that I notice the issue.

[GTRS Fiero]

I've been looking at symptoms for various components, but not found a match for my issue.

My plan is to unplug the ECU for a bit, then let the ECU re-learn.  My theory is that it may have learned while there was a vacuum leak at the EGR.

In any case, the RPMs do not increase when I put the transmission in drive, which seems odd.

Once the engine warms up, it runs fine, but when it's cold, it wants to die as soon as I put the teansmission in drive.  If I manually open the throttle, I can get going.

[TopNotch]

If an engine with a carburetor hesitates when you pres the throttle, it means that the acceleration pump in the carb is not squirting any extra gas to compensate for the rush of extra air coming from the open throttle.
In an injected car, the ECM must command the injectors to give that extra squirt of gas. For some reason, that may not be happening in your car.

[GTRS Fiero]

When I put the car in gear, it wants to die.  When I try to start moving, it again tries to die.

[TopNotch]

Have you checked the timing? (Even if it's DIS)

[Raydar]

...
In an injected car, the ECM must command the injectors to give that extra squirt of gas. For some reason, that may not be happening in your car.

That command would mostly be based upon what the TPS is doing. I might suggest adjusting the TPS for a slightly higher voltage. (If you manually move the TPS without opening the throttle, it will cause the engine to speed up, just by adding fuel and timing advance. Try it!)
Timing would be my second guess.

[GTRS Fiero]

Have you checked the timing? (Even if it's DIS)

Um, how do you adjust the timing on a DIS setup?

[GTRS Fiero]

That command would mostly be based upon what the TPS is doing. I might suggest adjusting the TPS for a slightly higher voltage. (If you manually move the TPS without opening the throttle, it will cause the engine to speed up, just by adding fuel and timing advance. Try it!)
Timing would be my second guess.

Manually move the TPS, as in, with my finger?  How would this not move the throttle?  Does the TPS add fuel and timing advance?

[Raydar]

The TPS "wiper" is actuated by a little lever, on the side of the TPS. The TPS can be adjusted by bending that little lever.
It's not fastened to the TPS itself, though. You can move it manually, while the throttle remains closed. (Kind of hard to describe.)
The TPS functions like an accelerator pump. Moving the throttle provides an injector "pump shot".  I think it also advances the timing just a bit.
I know that when I moved my TPS forward, leaving the throttle closed, as I described, it would speed the engine up, to a point. Nothing dramatic, but enough to notice. If I left it in one position, the engine would return to idle in a second or two.

[GTRS Fiero]

Well, I unplugged the ECU for 10 minutes, then plugged it back up and went for a 20-minute drive.  Initially, I drove on flat streets in the subdivision.  After the first few seconds, it ran fine.  Perhaps the occasional hesitation when accelerating from a stopm but OK.  Then I left the subdivision, which included going up a hill, then driving down to a stop at the other side.  After I stopped, the engine died.  I went down the highway about 2 miles, then came back, having a little fun with a Sonata on the way.  My Fiero performed admirably.  I drove through the subdivision again without issues.  I then exited, and drove down that hill.  Same result.  I returned down that hill a third time, with the same result.  I returned a fourth time, and managed to go without the enhine dying, although it certainly tried to die.

It almost seems as if my TCC is causing issues.  I just don't know why a hill would trigger such.

Certainly, after 20 minutes, everything should be warm.  I went through all the gears.

I should also mention that the temp on my gauge only gets about 1/4 of the way.  I suspect this is a gauge or sensor issue.

[GTRS Fiero]

I had unplugged the TCC, but there was no change.  Since the tank is at 1/4, I wonder if the fuel is running to the front of the tank, and the engine is dying from starvation.  Easy enough to check.

[GTRS Fiero]

That wasn't it.

[Raydar]

I had unplugged the TCC, but there was no change.  Since the tank is at 1/4, I wonder if the fuel is running to the front of the tank, and the engine is dying from starvation.  Easy enough to check.

You might be on to something. Do you trust your gauge? Most Fieros tend to suck wind at 1/4 tank indicated, unless the sender has been "looked at". It's quite possible that the fuel is running away from the pickup.

[GTRS Fiero]

Well, my sender has been replaced, along with the pump, sock, pulsator, and fuel lines/hoses.

I filled the tank, and there doesn't seem to have been a change.  My fuel gauge drops quite a bit, the first 20 miles, but the more empty it gets, the more accurate it seems to be.  I'm really only concerned with the empty side being accurate, anyway.

[TopNotch]

Um, how do you adjust the timing on a DIS setup?

You can't, but you can replace what's causing it to be off. Have you considered the crank position sensor?