'88 Cavalier won't run

[mikemeier215]

I have a 1988 Cavalier that I just bought for my daughter that's driving me nuts! After warming up, or if the ambient temperature is high (80's-90's) the car will die or not start. It acted like it was not getting fuel. Sure enough, after it died I pulled the air filter cap off and checked for fuel. When the starter is cranked, no fuel was being pumped down the throttle body. I replaced the fuel pump & filter. It worked great upon test driving until I turned it off and tried to start it again. It wouldn't start! The service engine light comes on, and I had the code read: a bad ignition control module. I had that replaced, but it seemed to make no difference. It starts fine if it is cool, but once the engine warms up it dies. I took the car to a shop with a great reputation, who dianosed the problem as a bad ignition control module (the new one, mind you). Not only did they read the code on it, but they checked the computer brain, and the wiring leading up to the ignition control module. Then they checked the resistance within the module itself and confirmed it was getting hot and malfunctioning. I had it replaced again and once more, it ran great for an hour or so until I shut it off and tried to start it again. It will fire for 1/2 a second or so, then dies. I can guess if I spend another $250 on this $800 car for a diagosis it will tell me the ignition control module is bad. I need help before I get arrested for blowing this car up.

[public]

Any time you have a temperature related issue on this car check, and if good, clean your IAC valve. This performs the choke function and can play havoc with the fuel/air ratio.

If this does not work I would suggest checking your wiring very closely. You may have a short that is killing your new Ignition Modules.

Finally: If it STILL does not run,

A cheap shotgun would be to replace the Crank Position Sensor and the Oil Pressure Sending Unit. These feed info to the Ignition Module to provide spark and fuel. If the Oil Sending unit is bad the ICM can stop firing your injector(low oil pressure safety). It is only a $4 part but it is kind of hard to get to. The Crank Sensor is a little more expensive. Both are on the back of the block, so lift the vehicle as high as possible for easier access from underneath. Good Luck.

[mikemeier215]

Well, it only gets better. Today I returned the ignition control module to NAPA (the first one I bought). In order to get a refund on the "defective" part, they had to test it. They heated it up three times, and it showed the module was just fine. he NAPA clerk also mentioned the heat sink grease, the first I had heard of it. She did say it wouldn't heat up athat quick and cause the problems I am having. I haven't hear of these other sensors you speak of. I will check those. Thanks.

[public]

I agree with her, you need the heat sink greese although I have seen the ICM work just fine without it. A Chilton or Haynes manual will have proceedures to check these sensors except the Crank Position Sensor. You may wish to try a junk yard unit if everything else checks out fine. I really do not feel that the Crank Sensor is your issue, just a possibility.