I got a used opti for a 94 from a guy on f-body.com and it looked real new, inside and out. I bolted it on today and guess what, no start. Scanned it, no codes. No RPM showing on Snap On scanner while cranking it over. I double checked all connections and grounds, theres not a lot to take off when you do the opti anyways. So ive got no spark obviously since the PCM seems to not be reading RPM which is the optical eye not picking up. I checked the 12V and the 5V leads in the opti harness unplugged and theyre fine. I plug it back in and the 5V reference is gone, like the opti is shorted internally. Curiosity got to me and I pulled the plug from the opti itself and checked that out and it looked fine, then I plugged my old opti in, which still ran the car, and the 5V reference and the 12V leads stayed normal, plugged the connector back into the one on the car, the 5V ref. disappears. Any other ideas or are my assumptions correct?

 

Sounds like a bad opti.

 

Yeh u might want to contact the persone u bought it from and try to get your money back.

 

anyone else got any last minute suggestions b4 I rip it back off? I seems straight forward to me.