91 Camaro 5.0 engine, 31,000 miles, one owner, ME. The problem I am having is that after about driving 8 miles from a cold start up the "Service Engine Soon" light comes on. When I turn the engine off it tries to restart but won't. The engine turns over fine when trying to start but runs for a couple of seconds and dies. After waiting for 15 minutes to half an hour it starts right up The engine runs GREAT when started idles like a purring kitten and when pushed into passing gear it roars like a lion. Recently installed new plugs, plug wires, D Cap, Rotor, Coil Pick-Up, Ignition Coil, Ignition Module. Fuel pump about a year old. How could an engine that runs like new then not want to re-start but when it sits awhile it starts and runs great. SUGGESTIONS?

 

something is getting hot and not working right. since you just changed out all the ign componants id say its one of them. the icm generally is more prone to heat soak.

 

The same problem was going on BEFORE I changed out all of the ignition parts. It couldn't be the NEW ignition control mondule is also bad because that would mean that BOTH the old one and the NEW one are bad, not likely. Besides, if the module was bad it would run bad all the time not just on a hot re-start. Thanks anyway for the suggestion.

 

well the problem is heat is most likely getting to it from the sounds of the problems youre having. icm + heat = crappy running.

 

It doesn't run "crappy" it runs beautiful, it just won't restart until sitting awhile. You need to re-read my first post over. If it was the icm it would run crappy, it runs fantastic all the time when running. It's just getting it to re-start.

 

I didn't see any where if it's carbed. tpi, tbi, or what? If it's a carbed motor, could it be flooding out?

 

It's a 91 Camaro with 31,000 miles on it. I bought it new in 91. They did not come with carbs, TBI is what was stock on the 91 RS 5.0. I wish the damn thing did had a carb along with points and condensor, I hate these new cars with all of this electronic crap that seems to change every model year.

 

I would have the "new" ignition module checked anyway, I've been through 2 or 3 "new" ones on my HEI setup.

 

If the new one was bad wouldn't the car run bad. I can drive from Orlando to Daytona Beach and back without stopping and it runs great, never misses a beat. It's only when I get back home and turn the engine OFF that it will not re-start. It seems to me if the Ignition Control Module was bad it would not be able to make that trip with no problems other than the "Service Engine Now" light coming on after about 8 miles. Anyone else have a suggestion?

 

As much as I agree that two ICM in row having the same failure is weird, a heat related failure will act just like what you're describing. Run beautiful until it gets hot, then nothing. However, before you replace any more parts, I would do some testing. First, when it won't start, find out what is missing. Is there spark? Is there injector pulse? Is there fuel pressure? Injector pulse and spark both start with the pole peice and timing core, through the ICM. Injector pulse of course is generated by the ECM from the crank referrence signal which comes from the ICM.

Does the fuel pump prime for two seconds? That means the relay and pump are okay. If it primes then doesn't run while cranking, that means the the ECM isn't commanding the relay on. Which probably means it isn't getting the crank referrence pulse.

Assuming the ICM is okay, the pick up coil can also suffer heat related failure. It is just a coil of wire. You can test the pick up coil with an ohmmeter. It should test between 800 and 1000 ohms.

 

I know that electronic engine controls can seem complex but actually the early systems on these cars are relatively simple compared to most of the cars I diagnose everyday. And as complex as these cars may get to be, alot of the problems they come in with turn out to be simple after all. I suggest getting hold of the Helms Publishing Factory Service Manual for your car. Obviously you've had this car for some time and I would assume that you're goung to own it for some time longer. In this case, the book is a good investment. A thorough study of section 6 of the manual will provide you a wealth of information on the workings of your car's engine and controls.

 

Take off the air cleaner and look for a puddle of fuel in the bottom of the intake. A bad TB injector will have a tendency to leak after shut off flooding the intake. The car then won't start again until it airs out and defloods itself. Similar to what the plugs used to do on the bottom of the old Q-jet's.

 

Thanks, I'll look for fuel. I think it's something simple since most of the ignition system is new and the car runs like the day I bought it, except for the re-start issue. I did put some injector cleaner and conditioner in the fuel tank this week. I bought a gallon of the Lucas brand at Advance Auto Parts. I should have done this years ago.

 

Anti-venom...this is why I read this forum for info like this. I'm mostly a carb guy and never knew something like what you described could happen. And I'm sure that probably a bunch of people who own TBI cars never knew this either.

In all my years working on cars, the fix always seems to be something simple or overlooked at first glance. Mayeb the OP will get lucky and this simple check will solve his problem.

 

I took the Camaro out and again the "Service Engine Soon" light comes on after about 6 to 8 miles. The engine is still running great, smooth as silk, plenty of power, come home, turn off the engine and try to re-start, engine turns over fine but won't start. Take off the air filter and look for leaking injectors, nothing. Wait about five minutes and look again, dry as a bone, no leaking injectors. I was almost wishing they were leaking. Now I am back to square one. Engine runs fantastic but won't re-start after getting hot. Let it cool down and it starts fine. Anymore suggestions?

 

BTW, when I do try and start the engine when hot the fuel pump does come on for a couple of seconds and yes I did change the ignition coil along with the other ignition parts. (SEE FIRST POST in this thread)

 

umm

what is the code it's throwing? did you jumper the port and jot down the code?

 

I don't know what the code is, don't have the right tools. I guess I'll have to take it to someone who knows more about this than me. I'm old school, points and carb, Rock & Roll. I've been around long enough remember when you could buy a new 68 Camaro for under $4000.00 and could work on it under a shade tree with few tools. I still have a 63 Ford Falcon convertible I can almost work on with my eyes closed. It's nice to be able to change a fuel pump hooked to the side of the engine in 15 minutes at a cost under $30.00 and can change the spark plugs in about the same amount of time. I will LEASE from now on and give the POS back to them every other year.

 

getting the codes is duck soup

you need

a pencil or pen
a piece of paper
a paper clip or small piece of wire


locate the ALDL port which is near your right knee when you are in the driver's seat

with the key off, put the paper clip or jumper wire into the top 2 right side holes of the connector

put the key to run

it will flash codes in sequence

jot them down