1995 LT1 Trans Am Automatic. Recently replaced the opti, TPS, Inlet air temp sensor, and spark plugs. I can go outside right now and it will start right up, runs fine, but (after it warms up) it will stutter under hard acceleration (not all the time, just occasionally) and cut off at a stop light. Sometime it will start up afterwards, sometime it takes a few minutes of just letting it sit to start up, but it's usually hard to keep running after that and it's stranded me 3 times now. I get NO check engine light. I'm trying to figure a way to drive around with a fuel pressure gauge hooked up to see if I'm losing fuel pressure, but it's solid pressure at idle (about 42psi). I'm thinking IAC or ignition module, but have to way to confirm that...Can anyone offer some words of advice please????

Many thanks.

 

I have seen several things cause the dying when warm symptom. You can remove your coil and ICM and take it into AZ and test them both. Find a way to heat up the ICM before/during testing. Torch the back plate (gently) as they usually fail only after getting hot.
Another thing I have seen that might be an area of interest would be any sensors that are used in closed loop (when the car warms up) such as the o2's and the MAF. And finally, try swapping your temp sensor on the water pump. I know it sucks to diagnose something with no codes, and it sucks more to throw parts at a problem with no results. Good luck man.

 

I'm thinking possibly the MAF or o2 sensors. The MAF can cause all kinds of havoc on a computer. And one of my o2's are shot and it runs like *** and studders. They're unplugged and now the car runs great. Rich, but great. (I have new o2s and plan on doing a cam swap now)

Good luck!

 

Hey guys, thanks for the words of wisdom. Is there a way to test the MAF or O2 sensors? I'll be taking the ICM and coil to autozone tomorrow.

 

Not really. You can clean the MAF with electronic parts cleaner and see if it makes a difference. Also you can unplug both the MAF and o2's and see how the car runs after that. Doing that will force the car to run in open loop. If it runs better, either the MAF, o2's, or both could be the cause of your troubles. Post up the results of all of your tests. Don't forget to heat the ICM while testing, and test it multiple times, not just once.

 

that is what i would do.

 

Ok...I did several things at once. Removed coil and icm. Autozone tested the coil and it failed. Could not test the ICM...didn't have the right plug. Cleaned the MAF with electronic parts cleaner. Cleaned intake and MAP with carb cleaner. Reinstalled coil and icm (spaced it out away from the cylinder head this time with longer bolts and washers. Cranked up and ran fine (did that before). I let it run for about 20-30 minutes with the hood shut and no problems so far. I'm also trying to fix an oil leak at the bottom of the timing chain cover, so the RTV has to dry for 24 hours before I should drive it. I plan on driving it Sunday and I'll see how it does. I'll post my results.

 

Nice. I'll keep my fingers crossed for you.

 

Idled for 30 minutes, then drove about 15 miles, no problems yet. Temp here is only about 40 and raining, so if it's heat induced I'm not positive it's fixed yet. If it acts up anymore I'll post. Thanks guys.

 

Best of luck!

 

Ok this thing is pissing me off...I have a dd, so I'm not on this everyday, but I took it to home depot tonight (less than 3 miles away) and it did the same thing. Just cut off. It's like someone reached over and turned the ignition switch off. When it happened the first time I pulled over and put a fuel pressure test gauge on and drove again. The pressure gauge never dropped, so I'm back to thinking ignition again. I called around and found an autozone that has the right adapter to test the icm, so I'll pull it off tonight and get it tested tomorrow. I'm not convined the icm is the problem. Am I wrong?

 

Im thinkin MAF

 

I think it's either the MAF, o2's, or ICM.

 

ICM tested good at autozone. Tested 6 times. I didn't have a way to heat it before the test though...Still have no check engine light on. MAF is $175!, ICM $80, holy crap batman!

Anyone looking for a nice 95 T/A??

 

when it will not start is it turning over or is it doing nothing

 

Turning over just fine. If it cuts off I usually have to wait 10-30 seconds before I try to start it again. It will turn over immediately, just doesn't start unless I wait.

 

Did you try unhooking the MAF and o2s to see if it works? If you did I'm sorry didn't see it.

D

 

Not recently, I will try that next.

 

did you replace the wire plug thingy that plugs into the opti?ias much as i hate to resort to the old faithful and blame it on the opti...

 

Did you check all of your grounds?? Pull your pin connectors and ohm the wires to rule all of them out. Get it hot and acting up and do the same. May be a symptom of a sensor you replaced, but still causing a problem due to a wire grounding or getting hot after it has ran. Probably something deceptively simple.