Please help me! I have an 89 corvette that starts right up on cold starts and runs fine but if you shut it off and try to restart it engine turns over but wont start. Had vehicle checked by a dealer they are telling me they received no codes so I need to start by replacing fuel injectors, mass air flow sensor, and EGR valve to start and see if that doesnt fix problem. I had the electronic controle module and replaced it did not solve the problem could be bad did put an aftermarket one in with my old chip. Any suggestions from anyone please dont know where to go from here. Thanks!

 

I have the same problem as you i think, if you can check to see if the drivers side header is getting hot, mine is not, after i crank it over it runs for 30 secs to a min then stalls out. seems like the drivers fuel injector rail is not working, my next step is to test the injector connectors with a noid light. ill let you know what i find.

 

yes I had my injectors checked and they said the light stays constant pretty much but I was wondering would the ECM have anyhing to do with that or my chip may be bad I put in it because doesnt that tell the injectors what to do?

 

What chip did you "put in it"?

 

I suspect you just asked the right question.

 

The proper way to fix a car is to make some measurements to diagnose where the failure is, the most stupid and expensive way to fix a car is to just start replacing parts. I don't know what the testers meant by, "the light stays pretty much on". Injector drive can be tested with a noid light which comes on when the ECM supplies power to the injector. This power is in the form of 12v pulses, so the noid light pulses when you crank or run the engine. If the noid light is on constant, you have a problem because the ECM is not PULSING the injectors. The time to diagnose the engine is when the problem exists. From page 1 in any auto repair book, engines need hot spark and spark at the correct time, fuel and air and in the correct ratio, and cylinder compression in order to start and continue to run.
When it won't start, use a timing light to see if you have spark and spark at the right time during cranking. Unplug a spark plug wire and hold a grounded wire inside the boot while someone cranks, you should have a snappy at least 1/2" long spark. Measure the fuel pressure, it should be 35-42 psi and with the ign off, it should hold up for at least 1/2 hour or you may have leaky injector/s or a defective check valve in the fuel pressure regulator. Connect a noid light to an unplugged injector socket, you should see it pulsing during cranking. Measure the injector coils with an ohmmeter, they should be about 16 ohms, however, an ohmeter will only find gross coil failures. A better electrical test is to use an impedance bridge and measure the injector coil inductance and Q, all of them. You can still have defective injector/s that don't spray fuel when hot and there are places that exercise the injectors out of the car to see if they work properly. Check with FIC injectors, a forum supporter.
A common failure to start when hot is the spark module which recovers when it cools off. Checking for spark with the wire in the boot will show if you have a strong spark or not. Some auto parts stores can test spark modules, test it hot. Spark modules aren't expensive and replacing it is a cheap test.

 

Thanks for the advise I did have dealership say that 6 out of 8 fuel injectors were not holding resistance just dont know if I can trust them. I did put my old chip in the ECM however I used an after market ECM should I have used a GM one.

 

I absolutely agree with JFB. Only way to go.

FWIW whem I had your problem it was the ignition module. Generally when warm starting is the problem it's the ICM. Cheap and easy to replase.

BUT I still agree with JFB

89 red coupe

 

Thanks I guess I need to get car out of shop and check these things myself. Thanks I will let you know when I get it back to the house.

 

Ensure you have spark at the plugs....you may need to crank the engine several complete revolutions.

Do some fuel pressure checks.

Check for injector pulses at the harness...again you may need to crank the engine several complete revolutions.

Injector specific problems - next time you get your no start when "hot" condition:

Unplug a few fuel injectors (one from each bank) and try to start the engine again.

Remove the bellows off the front of the throttle body and spray a 5-8 seconds spray of starting fluid in past the throttle blades reconnect the bellows and attempt to start the engine to see if it fires up for a few seconds or longer.

If your '89's fuel injectors are the stock problematic Multech's change them to an ethanol compliant type injector as many others have done.

 

inside the dizzy, the ignition module...fits reported symptom...failure so common that i carry a spare ign module and tools to change out in all my HEI equipped cars, has gotten me 'on the road again' several times.

 

Thanks for advise will check fuel injectors and the ecm have car back in my possesion now.

 

redrose will check ign module thanks