Project 87 IROC in the works... Converted to speed density including under hood and the interior wiring inside the car. Old Dash guage custer removed, now has electronic 91 cluster. Removed the old speedo cable from trans, installed new electronic VSS in trans but does communicate with ECM. Tac, oil pressure guage, batt and fuel guage work. Any suggestions? Thanks!

 

Did you also install the "speedo buffer" yellow box that's in the stock '91 harness? That may or may not keep it from working (not sure....it's been years since my wiring was stock.)

 

The VSS buffer box on the camaros is only available on the TBI models.

 

The wiring from the VSS to the ECM tests okay, no opens. But, still no speed o. Suggestions? Thanks for the help!

 

There has to be a brown wire from the ECM to the plug on the instr. cluster going to the speedo, have you checked for that ?
Did you use the '91 VSS? It's different from the '87.

 

The donar 350 TPI engine, harness, ECM and the entire interior wire harness, guage cluster, dash, steering column and air bag system were taken out of a 91 Trans Am GTA. I then transplanted 100% of it into my 87 IROC. I did however keep and have the 87 700r4 rebuilt. It had the speed o cable which I took out and then installed the VSS sensor. At this point, I'm really wondering if the VSS sensor may be the wrong unit as I did not have the original when I ordered the replacement from GM. I did have the donar car vin that we used to select the part but then again, ==== happens. At the time I wondered about the price, seemed too good as I just went through this with my 91 RS and the VSS sensor cost about twice the price.
I do have the wiring pinouts for the electronic cluster so, I'll make sure that theyre good to the speedo...theyre good to the other guages and they function. Kinda points me back to the sender.
Am I headed in the right direction? Thanks for the feedback!

 

Problem solved! Speedo works! No wiring grimlins. The first VSS sensor that I installed was the culprit! Even though it was a new Delco part, the incorrect unit and the correct Delco unit differed by one number, the very last number. Thank you everyone that took the time to respond.