1996 Lumina problem

[Joseph Upson]

I'm putting my money on your PCM as the problem. You describe an issue that gradually grew worse. Crank sensors usually don't come back to life when they go bad, injectors going bad in pairs is pretty much unheard of and if they did the results would be persistently bad for the most part and they wouldn't stop the fuel pump. The fuel pump will not prime if the PCM does not tell it to so if the pump and relay are good as well as the associated sensors I would start suspecting the PCM. My ECM blew its fuse a couple of times and occasionally made the car stumble before it finally made the situation clear when it started to burn and give off smoke.

The ignition module is the other suspect given your problem's sensitivity to temperature, the more assessories you turn on, the harder and longer you drive the car and the warmer it is outside, the hotter these two pieces of electronics get. I believe your PCM is under the hood so it will definately feel the heat along with the module. It appears the mechanics threw parts at it and crossed their fingers.

Here are two ecm related issues current on the Fiero forum now:
http://www.fiero.nl/forum/Forum2/HTML/111033.html

http://www.fiero.nl/forum/Forum2/HTML/107810.html

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[snappin]

I was thinking it is the PCM as well, but unless I tow the car to the dealership and have them to hook it up to their computer there is no way, that I know of, to test the PCM. If we bypass the fuel pump relay and it's getting gas it still doesn't run until it cools off for a while, then it'll crank up and sputter. I figure if it's getting gas to the injectors, getting spark, getting air, then maybe the PCM isn't telling the injectors to fire. Like I mentioned before when it does run you can really smell the gas in the exhaust. I can get a remanufactured PCM for $100 and then it's another $50 to have it flashed. But I don't want to put another $150 into it when I don't know for certain this is the problem. I've put waaaay more into the car then what I wanted to. Anyone know of a way to test the PCM? I've asked a dealership if I could just bring it in and they said "no", no surprise there.

[snappin]

Well I finally got the car back from the mechanic and he ended up putting a used PCM from a salvage yard in and it fixed the problem. I'm still in the process of driving it and making sure it's fixed, but as of right now that's what the problem seems to have been.