Long story short ive got a 94 corvette that dies randomly then refuses to start until i replace the opti. ive used a variety of differnt optis coils icms wires plugs and the car still fails the same way each time...runs perfectly then stumbles once. 1 minute later i lose all power and it stalls. battery light comes on no CEL and the car refuses to start again. Code 41 doesnt go away. i replace the opti and the car runs fine again. unsure if i have terrible opti luck, the opti hasnt been the problem this whole time, or something else is broken and causing my opti to fail. here are all the tests ive ran and their results:
- Battery is new and in good condition
- Fuses are all in good condition
- msd 6al box has been removed from system and failure persists
- used 6al box to force fire my coil and it did fire. according to msd this means the coil is okay. attempted to start car with msd coil and stock gm coil both fail
- checked voltage at icm connector terminals A and D. A has 0.9v (issue) and D has full 12v
- Good ground at icm connector C
- Terminal B reads 0.2vAC (issue) when cranking. continuity between terminal B and pcm is good
- continuity between icm connector terminal A and its corresponding ignition coil connector is good. same goes for terminal D and its corresponding wire at the ignition coil

Any addional tests or suggestions would be greatly appreciated.

 

I had a similar problem with my 93 running great, sputter to the side of the road. Change Opti 4 times
On Opti 4 I was doing the normal that we all do after you get done with a fairly intrusive repair, had the car running waiting on a little temperature to top off coolant and neatening up wire looms checking things.
As I was tucking in the coil ESC wires the car shut off, restart giggle wire's shut down. What was found was the pink wire was 1 strand and some of the other wires were not happy either.
Fix them at the cost $20 with replacement parts

 

very interesting. my pink wire is only reading .9v but should be 12. resistance of the wire is good too. visually the wire looks okay is there a way to test its quality without depinning it?

 

same goes for my signal wire. its reading .2vAC it needs 1-4vAC. since its not 0 its getting some flow but clearly not enough. jiggling my wires doesnt seem to help the car start the only thing thats fixed this has been replacing the damn opti for some reason.

 

Code 41 diagnostic for a 1994…video if followed should pinpoint your issue.

 

I found the problem just moving and slight tugs in harnesses
Also keep an eye on the coolant temperature sensor on the water pump that can do the same shut down but will probably throw a systems code

 

watched it. i dont have any signal to the tach nor do i have the special volt meter or scan tools n software.

 

UPDATE
- Swapped ignition coils to my stock gm coil and i got 12v on the pink wire terminal A. will proceed with all further tests using that coil
- Car failed both LED light tests on terminals D and C. test light never came on or flashed
- Car does make a noise when unplugging or plugging in the msd distributor. Sounds like injectors priming but ran a noid light test and i have 0 injector pulse