1994 Corvette Coupe Engine Problem?
Thread Starter
Heel & Toe
Joined: Dec 2009
Posts: 18
Likes: 0
1994 Corvette Coupe Engine Problem?
My 1994 Coupe has 90000 miles on it. About 5 weeks ago, my C4 would just stall for no reason out of the blue. After stopping the car, I would be able to restart within about two minutes. Sometimes this would happen 3 or 4 times on a short drive, sometimes I could drive 50 miles and it wouldn't happen at all. After getting some ideas from "Corvette Forum", I decided to change the ICM. I replaced the ICM with a new ICM and the car still stalls or quits. Same symptoms.....dirving along,car running great. next thing I know, engine just quits. I'll coast to a stop and restart the engine. Can anybody point me in the right direction? Any ideas? Thank you all very much....I really do appreciate any logical comments.....
Intermediate
Joined: Sep 2006
Posts: 38
Likes: 1
Here are a couple of things you can try after it dies in order to diagnose if it is ignition related.
1. An inline spark plug test light connected to the coil will allow you to see if the coil is firing while cranking. If the coil is firing consistently and strongly then it is likely that the coil, ICM, ECM and associated wiring are ok. If the coil is not firing then you will need to isolate each component including the distributor to see what is wrong. It would be best to get a factory service manual if you want to do this although there is a lot of info about doing this on the web.
2. If the coil is firing then connect the inline spark plug test light to one (or several) of the spark plugs, start cranking and see if the energy is getting through the distributor to the spark plugs. If the spark plug light is firing consistently and strongly then you will need to expand your search for the problem to the fuel system, etc. It would be best to get a factory service manual at this point. If the light is not firing while cranking then the problem probably lies inside the distributor.
The link below will show you how to check for Diagnostic Trouble Codes (DTCs).
http://tech.corvettecentral.com/2011...trouble-codes/
1. An inline spark plug test light connected to the coil will allow you to see if the coil is firing while cranking. If the coil is firing consistently and strongly then it is likely that the coil, ICM, ECM and associated wiring are ok. If the coil is not firing then you will need to isolate each component including the distributor to see what is wrong. It would be best to get a factory service manual if you want to do this although there is a lot of info about doing this on the web.
2. If the coil is firing then connect the inline spark plug test light to one (or several) of the spark plugs, start cranking and see if the energy is getting through the distributor to the spark plugs. If the spark plug light is firing consistently and strongly then you will need to expand your search for the problem to the fuel system, etc. It would be best to get a factory service manual at this point. If the light is not firing while cranking then the problem probably lies inside the distributor.
The link below will show you how to check for Diagnostic Trouble Codes (DTCs).
http://tech.corvettecentral.com/2011...trouble-codes/
Thread Starter
Heel & Toe
Joined: Dec 2009
Posts: 18
Likes: 0
Don't have a scanner....I did replace the opti last year (Summit) and have baby'ed the heck out of it by keeping it dry as a bone.....ICM was an easy job....Could it be ECM or maybe Fuel Pump? I really don't think it is the optispark....when the last one went, the car didn't start back up until I put in a new one.....
Drifting
Joined: Jun 2010
Posts: 1,853
Likes: 8
From: Westerly RI
A problem like yours can be fuel or spark related. When the car stalls, see if it will fire with a small sniff of ether into the intake while cranking. If so, you have a fuel issue, you can go from there- pump, filter, fpr, etc.
If this produces no results, I would look for spark, starting at a plug wire. Short a wire to the block while cranking, look for a spark. Or, use an induction-type timing light, or, as mentioned, a tester.
I second the suggestion that you get the '94 FSM.
If this produces no results, I would look for spark, starting at a plug wire. Short a wire to the block while cranking, look for a spark. Or, use an induction-type timing light, or, as mentioned, a tester.
I second the suggestion that you get the '94 FSM.
