The other day I tried to start my 1995 Z28, and it cranked for 10 or 12 seconds before finally running. Usually fires right up. Once it got running, the check engine light went on.

I hooked up my ALDL cable to my laptop running scan9495. I got DTC 36 and 41. 41 went away, but 36 stayed even after clearing the code. I just replaced the opti a couple thousand miles ago along with the water pump, wires, plugs, etc.

I went to shbox's website and looked at his troubleshooting guide.
These are the results of my wiring harness tests:

ICM Harness pinouts-
A= 11.93
B= 0.08-1.3
C= 0.017
D= .11.92

Optispark Harness pinouts-
A= 5.02
B= 4.97
C= 11.93
D= 0.0

All of these results look OK, with the exception of ICM pin B being on the low end.

Any suggestions on what the problem might be? Unfortunately, it's looking like it is the Optispark again, but if there's anything else I can try first, I'd rather do that, because doing an Optispark swap is a giant pain in the butt, and I don't want to just throw parts at the problem.

Thanks in advance for any ideas.

 

It's gonna be the opti or opti harness.

 

Damn. That's what I was afraid of. Thanks so much for responding. Your website has been an invaluable resource, especially since this is the first 4th gen I've ever owned.

I know this gets asked a lot, but since new old stock AC Delco or Delphi units are pretty much impossible to find, are there any other aftermarket ones that have a decent track record now? Did anyone figure out any other cars that might have the desired Mitsubishi optical sensor that I could transplant into a new opti?