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My 1992 C4 Corvette will suddenly stall after driving for just a few minutes. When I try to start it back up, it will turn over buy won't fire. have to let it sit for quite a while then it will start again.
I can sit in Idle for half an hour or so and it won't stall on me, but the second I put it in drive and go a half a mile, dead.
The only codes that come up are 1. H72 4. H26 and 9. H72
Also, when the car is off the interior lights won't shut off unless I remove the LCD fuse.
The car has an aftermarket stereo and an aftermarket ignition system which I had a Chevy dealer remove the ignition system, but it did nothing to solve the problem.
How do I test the ICM? and for thermal grease?
Kindly explain, I am a beginner to these cars.
It seems to always stall when the coolant temp is around 208-210 which I thought was normal operating temp for the LT1 engine.
How can I tell if its a spark problem or a fuel problem? Is maybe the ECM telling the fuel pump to turn off at a certain temp? The car starts completely fine when its cool but just will not fire when its hot.
p.s
There's also a very strong smell of gas coming out of the exhaust when I first start the car. Not sure if that's related or another issue, or normal for this car. Could simply dirty fuel injectors be causing all these issues?
Put a fuel pressure gauge on it and tape it to the windshield. Pull a spark plug wire off and look for spark. Most part stores will test your ICM and coil for free. Might need to go to a few of them many do not know what they are doing.
I would also pull the vacuum line off the FPR and look for fuel. Some have had fuel injectors that would do this too.
I would start with testing the ICM and the coil.
Last edited by antfarmer2; 09-19-2016 at 07:18 PM.
The ICM (Ignition Control Module) is mounted on the front of the passenger side cylinder head. It's the power unit that gets the signal from the computer and tells the coil when to fire. When the ICM gets too hot, it will shut off or become intermittent. It is on a little finned aluminum piece with the module mounted on the front and the aluminum finned heat sink mounted to the front of the cylinder head. There is white thermal (heat transfer) grease between the module and the heat sink and also on the back side against the cylinder head. That grease dries up after a few years and doesn't transfer heat like it should. Electronic stores sell it for power transistor heat sinks, but I think you can get it at automotive part stores too. Mine was a little bit of a pain to get off as it's captured behind the power steering reservoir bracket bolt.
09-15-2016, 08:07 PM
1992 losing spark after a few minutes
