Hi, I am in dire need of some help as I am baffled and lost. I have a 1987 GTA I am the original owner car has only 11,000 original miles. Car has been my baby for 33 years. The issue I am having has been going on for a few years. Car runs great, starts right up drives like new, but after bringing the car up to temp driving it around then turning it off and letting it sit a bit is where things go bad. The car restarts perfect and drives then 5-15 min into driving the car it looses all power and you have to pull over or it will just stall out. I let the car sit only 2-5 minutes car starts right up and runs fine again Car is 100% stock 100% original no mods, never raced, here is what I have done to the car so far.

Dropped and flushed gas tank and replaced electric fuel pump that went bad (unrelated issue) I was having the power issue before and after fuel pump replacement.

New spark plugs, new cap and rotor

New gas filter and air filter

New OEM Bosch MAF sensor as I had one.

New engine Temperature sensor (upper front of engine)

I really thought it was my catalytic converter that might have been clogged so I replaced that with a Magnaflow cat.




But nothing worked, like I said car looks and drives like it did in 1987 but if I go to a car show I will no doubt break down on the way home.
Everything else is original other than fluids, I really need some help here as you can see car still has the dealer inspection sticker from 1987 in the front window. Thanks in advance!
Guy

 

Have you checked any codes? Just a suggestion, but try a noid light and see if your injectors are dropping off when this happens. Your driver for them may be going bad, or the ECU itself may be going out.

 

Two things come to mind, ignition coil or the map sensor.

 

Those came to mind,

 

not real familiar with a noid light, as for a code reader not real sure what would be the best reader

 

I'd be looking at the ign coil, ign module and the pickup coil..

 

Thanks!

 

Sounds like the ICM is on it's way out. Here's the steps to troubleshoot it: https://easyautodiagnostics.com/gm/4...ed-icm-tests-1

I'd suggest you start looking for a Helms (factory) shop manual for your car; they're invaluable when doing any type of repair/maintenance, and they're becoming more rare every day.

 

ICM, thanks for your input I am looking at the comments and I see a few different thoughts good info tho!