I have just got back into LT1's after getting rid of my '97 Z in '03. I've never had an opti issue with that car (sold it with 90k).Having never had Opti issues, I'm not sure what the symptoms of an Opti going out are. I just picked up a '95 T/A. I knew it could possibly have an opti/ignition issue when I bought it. It would stumble real bad below 2000rpm, but clear up and run fine above that. Now, after a fuel sending gauge replacement, it wont start.
I have 42psi on the fuel pressure gauge, but no spark at all on multiple plug wires. I started with the easy stuff. I had autozone run 5 back-to-back tests on my ICM, its good. Coil tested good (Accel unit).Using my multi-meter, I placed the red probe on the coil terminal, and the black lead on both wiring pins and got a reading of 9.41 on both terminals. Ignition fuses are good, and I have power on both sides of the fuses. My SES light is on, but I dont access to a code scanner that will work on my 95 since its OBD1 with an OBD2 ALDL port.

 

Im not sure I understand this last part. Have you tried scanning it?


When my opti started going bad, it would stumble really bad at low RPMs. This very well could be the problem.

 

No I have not scanned it. I cannot purchase locally a scanner that will work on my car. The OBD1 scanner will not physically connect to my OBD2 style ALDL port.
My OBD2 scanner will not read the OBD1 computer....

 

Many OBD-I scanners have a 12-pin to 16-pin adapter plug to allow them to connect to the 95. Or if you don't happen to have the adapter plug, use Shoebox's jumper method:

http://shbox.com/1/xraycable.jpg

 

I went ahead and ordered an Opti. I also found that the PO broke the Opti harness locking tab, and instead of replacing it, RTV'd the harness to the Opti, so I ordered a new Opti harness from EFI connection. I also remembered he said he replaced the waterpump about a month ago, which is also when the stumble started, so it sounds like he soaked the Opti.