Ok, I have a 94 z28. We've replaced numerous parts on the car trying to get it back to the way it ran from the factory, but everytime we replace something, a different part (usually electronic) goes bad. The issue now is that the car just plain won't start. For a few months, if the car was on for any more than a half hour, it died. If i waited about another half hour it would start and then die soon after, so i could only go about 6 miles or until the car died again(this went ont about 2 months). Thing is, the car ran like a champ when it was running, and gave me no sign of trouble. My mechanic went and replaced every vacuum hose, cleaned the IAC sensor, re-wired the IAT (throwing code), reprogrammed the PCM, replaced the opti-spark and plaugs/wires, put in a new MAP sensor. He checked the feul system and OKed the pressure from the regulator and fuel pump (replaced the filter also) I took the car back, excited that I had a z28 running tip top. The car had never run so well, but once I hit operating heat the next day, the car did its thing again and died......

The car is getting fuel and air, so spark has got to be the issue right? I've asked a bunch of opinions and everyone has been pretty keen on the ignition control module, so i replaced that. Still no luck.....The only thing left in the ignition i can replace is the coil. If that doesn't work I don't know what to do...Any ideas would be great.

Thanks,
Justin

 

Might as well replace the coil next. An apparent "good working" coil can go dead after it warms up, or overheats. I've had it happen. Only other thing, has the fuel system been tested after the engine dies? The fuel pump is an electric motor. It too could have overheating issues after running for a while.

 

Yes, they tested the pump afer the engine died. It checked out at the right pressure...thanks for the opinion, i'll give it a shot. If it doesn't work i'll be back lol

If anything else comes to mind about what it could be, let me know.
Thanks

 

You may also want to take a look at the ignition coil module, it also can act up when hot.

 

i changed the ignition "control" module. is there a difference between that and a "coil" module?

By the way, i replaced the coil and the car still won't start. I may as well change the wires leading into the coil from the harness. If the fuel system has checked out, and im getting spark (at least i think i am) can there be a bad sensor like MAF? will a bad MAF sensor cause the engine to not run? Could it be a bad cam position sensor?

im getting annoyed cause i keep dropping money into this thing without any luck. the only plus side is that I'm getting new parts lol.

Any more ideas?

 

Did you check your starter and does it have a wire for your alarm relay

 

starter is new. my car doesn't have an alarm...just the keyless entry and power locks and such.

 

also, can a faulty MAF sensor shut the car down if it gets too hot? or could there be a bad set of wires in the harness that go from the coil/module to the PCM? I mean the problem has got to be elctronic, but with all these new parts and no luck, i'm starting to question the wireing harness itself....anyone else had this issue?

 

First does your car at least turn over or is it completely dead.If it is completely dead check your battery cables and make sure they are OK.Check all your fuses,the ground to your pcm.Why is your car getting hot did you change your thermostat.It can also be a bad heater core.

 

Yeah, the engine turns over, it just doesn't start. When the problem was new i could drive the car for about 10 minutes or until it hit operating heat; then it died. It always runs at the correct temp.

One thing though...when the cooling fans come on, the computer throws a code for a bad IAT sensor. The motor isn't too hot, and the connections to the sensor have been replaced, but the light still turns on. I don't see how that could shut the car off or keep it from starting cause it's been throwing that code for a while.