Running out of fuel or air

[Wreck It Ralph]

I have one.  Not sure what year it's from.  I bought it to get the injector.  It has a bad injector in it, I think.

Does it have the round or oval top? Where the filter housing sits.

[Wreck It Ralph]

I think you can install a spacer plate and get the same effect.

As the Holley TBI? The Holley’s opening is 0.32” larger. Or from my understanding 300cfm more, I may be confused on the cfm but the opening I’m sure on.

[Fierofool]

Scott was the race car guy.  He can probably tell you what a spacer will do.

The one I have is round and has the fuel lines coming in and out on the driver's side.  It still has an injector in it.  I think it came from an 85.

[Wreck It Ralph]

Mine needs it on the passenger side.

[Fierofool]

If you want a new injector, last I looked, Rock Auto still had them.

[TopNotch]

So I’ve noticed at 4,000 RPM I’m running out of fuel or air. I’ve run plenty of cleaner through but I know I need to rebuild the tbi and change the fuel filter.

First off where is the fuel filter on the 88 2.5? I haven’t crawled underneath yet.

Second, can you get a slightly bigger injector?

Should I be looking for other problems

I know Pat said it runs out of air at 4500 but this feels too soon.

Ok, I just came across this thread, time to chime in. If you want to put an earlier (i.e. Holley) TB on your 88, you will definitely need an adapter plate and some fuel line plumbing.
But before you do that, consider rebuilding your existing TB. The fuel pressure regulator is in the TB, and that could be the cause of running out of fuel. It's not supposed to be adjustable (there's a plug over the screw), but I did adjust mine (after a complete TB rebuild) to the max pressure of the factory specified range.

[Wreck It Ralph]

I figured that was the next logical step.

Where or how did you check the fuel pressure after adjusting it?

[Wreck It Ralph]

Well I just ordered everything that goes on or in the TBI. $200 worth of parts. We will see what happens next.

[Raydar]

Wow. Spendy.
I would be inclined to check your fuel pressure. The book says 9-13 lbs for a TBI.
Per the manual, you will need to disconnect your fuel line from the TBI, and insert the gauge into the line. (However you're supposed to do THAT. I think that Pat permanently installed a "T", with a shrader valve, in his line.)

FWIW, I can spin mine to 5K with little trouble (if you can believe the tach.) I try not to do that, though.

[Wreck It Ralph]

Well I got the tool to check that 🤔

[Raydar]

I was going to suggest that your cat might be clogged, too.
To check, you can either unbolt the pipe in the "J" just before the cat (it will sound like an airplane) or temporarily unscrew and remove your O2 sensor.

[Wreck It Ralph]

I was going to suggest that your cat might be clogged, too.
To check, you can either unbolt the pipe in the "J" just before the cat (it will sound like an airplane) or temporarily unscrew and remove your O2 sensor.

What cat? 😂 it’s no longer there. 😂 but if anyone needs I have a back pressure gauge. Good for checking cats or potential collapsed muffler baffles.

Also the temperature test works great. A cat should be 75-150°F hotter on the outlet. If the inlet is hotter than the outlet then clogged cat. Easy check with laster temp gun.

[Raydar]

I was going to suggest that your cat might be clogged, too.
To check, you can either unbolt the pipe in the "J" just before the cat (it will sound like an airplane) or temporarily unscrew and remove your O2 sensor.

What cat? 😂 it’s no longer there. 😂 but if anyone needs I have a back pressure gauge. Good for checking cats or potential collapsed muffler baffles.

Also the temperature test works great. A cat should be 75-150°F hotter on the outlet. If the inlet is hotter than the outlet then clogged cat. Easy check with laster temp gun.

Well... allllrighty then! If it's no longer there, then I suppose it's likely not going to cause a problem.

Good info about the temperature test. I've got the laser thermometer, but never thought about using it to check the cat.
(I've seen a few blocked up cats, though. At night you can see all the pipes glow, up to the entrance of the cat. One person I know even boiled the clutch fluid out of the slave.
It also makes a V6 sound "wheezy". Revving it up produced... essentially nothing.)

[Wreck It Ralph]

Yeah glowing cats are cooler than leds though. 😂

[TopNotch]

I figured that was the next logical step.

Where or how did you check the fuel pressure after adjusting it?

See this thread.
BTW, the pressure regulator is clearly visible near the bottom of the picture.