if i disconnect wires to mc 81 corvette runs fine. plug it back in car starts and within 20 seconds dies , I can hold choke almost closed when mc plugged in and car will run???????

 

1. did you check for codes as suggested by the link you were provided in your other post?
http://www.early3rdgen.com/forum/viewtopic.php?t=25
2. you seem to be running lean if closing the choke permits the car to run.
So did you check for vacuum leaks in all the rubber lines in the engine compartment
Did you check the carburetor base gasket for a vacuum leak by spraying carb cleaner around it with the engine running?

 

my engine light isn,t working tried to check bulbs not enough time the b on comp. light test light when grd. thanks for answering will check all other items later.

 

Unplugging the mc solenoid puts the car in default. If it runs better, you have issues with any number of the CCC system.

 

open to suggestions,my check engine light or seat belt but check both bulbs and they are good, put screw driver between d/e on computor ,no response ,checked hoses and everything i could under hood. one mechanic said it's the ,mc solenoid,any thoughts. i,ve had 24 vettes first c3 electric carb. thanks , bill

 

If you put it in test mode, and have no response, the ECM is not working.
Get the dealers manual, and start hunting.
I could make a list, but its daunting at first.
Buy the 81 ECM manual if you can find it.

 

IF you know for a FACT that the CHECK ENGINE light bulb is good...and when you ground the two terminals in your ALDL connector under your ash tray and the CHECK ENGINE light does not flash code 12.

I would first look and see if you have a fuse holder in the right rear corner of your battery box. I KNOW 1982's have this singe fuse holder . AND it applies power to the ECM and other parts.

THEN...Honestly....you need to get a wiring diagram for this car. Specifically...you need to verify that the wire that you are trying to ground (assuming the ground wire IN your ALDL is actually grounded). You need to know that the wire you need to ground is not cut or an 'open circuit'.

Then I would also pull out the gauge cluster and verify that the printed circuit board is good by applying power and ground to the two circuits that would make your check engine light shine. That way I know the printed circuit board is OK.

I recently had to work on a 1988....where I could not get my scanner to communicate with the ECM and allow me any access to data when the car was running. The car ran somewhat fine...but without being able to see the data...it was pointless to do anything else until this problem was repaired. I replaced the ECM and PROM. That fixed it and actually aided the cars performance.

SO...before you go out to some place and buy an ECM and chip (which I would be somewhat careful about). And I would get both.

DUB