Chevy Corvette Wont Start- Blows Smoke

Question:
Chevy Corvette 1982 check engine light. I have changed ECU, module, spark plugs and plug wires. The car just died. The check engine light does not come on any more. Car would not run at all. I changed the ECU after checking the ECU fuse next to the battery behind driver seat. It as blown.

Somebody said the ECU need to be changed. After I changed the PCM the car engine runs. It was ok in idle for about 20 minutes. After running for a while the engine will start stalling and sending black smoke and smell like raw gasoline through the exhaust. Do I need to change the fuel injectors or how can I know if I need to change the injectors or any way to check if those are ok or what should I do. Please help.

Answer:
If you mean that the check engine light did not come on any more witht the key on or engine runnning, then yes, changing the computer was most likely the cause of that and the reason the car died out. The check engine light is controlled by the ECM. When it does not come on, that usually means the ECM is bad. Which of course will not let your Corvette start or run.

You did not say if the ECM you replaced was new or rebuilt or new. If it was used, I assume that is was the correct one for your car. If it is not the correct part then that is your problem with the smoke and running bad. Just any Corvette computer is not good enough. It MUST be the exact same part number. Also, whether it was new or used, the chip inside needed to be swapped over from the old one to the new one. Even if it is the correct part numbner computer, that chip must be changed. It is called a PROM. This is the calibration chip. It will not run properly without the correct one in it. Remove the cover on the PCM and make sure the PROM is properly seated.

If the car was not blowing black smoke before this repair, these things must be checked first.

If that is all good, then there are only a few things that can cause the engine to run that rich.
1. A bad ECM. The computer controls the ground side of the fuel injectors. If it bad or the wrong one, it can cause a 100% on time for them. You would need to install a fuel injector test light, called a noid light to see if it is flashing. If it is on steady, that is bad. Either the ECM is bad, or the ground wires are shorted causing the fuel injectors to be dumping fual all the time.
2. One or more injectors stuck open. You would need to perform an injector flow test to check for that. Also called a pressure drop test.
3. The fuel pressure regulator is leaking. When this happens, fuel leaks into the vacuum line and then into the intake manifold and causes a very rich condition.

After you find the problem, you will either need to replace the spark plugs since they are now fouled out and probably coated with black soot or at least remove them and clean them. Then take car for a ride to blow it out with some very hard acceleration.