Last night I thought that I would be able to fire up my car after swapping in a TPI 355. My car (91 RS) had other plans however. The TPI is an 86-88 model and it came with the stock wiring harness, but I'm sure I did something wrong because when I tried to start it, not only did it not turn over, but the lights inside did strange things. If I turned the dimmer switch one way, the speedo would light up and the tach light would shut off, and if I turned it the other way, just the opposite would happen. The fuel pump would work sporadically, and the headlights, radio, and power windows worked fine, but the car wouldn't turn over. When I turned the key to start it, it cranked once. And I noticed that the coolant temp guage would also fluctuate when I turned that ket. The starter is brand new. I'm wondering if this has something to do with the VATS, and if so, how do I fix it? Also, my VSS isn't hooked up because I'm not sure how to hook it up from the old harness to the new one. Could this be the problem? Should I get a new wiring harness? I'm not so sure that the one I was sent is complete. Any help would be appreciated, as I am about to hire someone to push my car off a cliff and collect insurance $$$. (shhhh... don't tell!).

 

I swapped from tbi to tpi on a 91 RS and used a new 90 model tpi wiring harness and there were differences in wiring between 90 and 91 and I think your problem lies in the wiring harness. The problem I had was that a ground was in a different place but was an easy fix. Your best bet is to get a 91 Z28 wiring harness.

 

Somewhere along the line you've messed with your chassis wiring by accident. The engine management wiring and chassis wiring are two separate systems. One can be removed without affecting the other. You've cross wired them by accident.

Good luck

 

That makes sense, crossing the wiring. Could it be because I left the old lead to the starter solenoid on, and also put the lead from the 'new' TPI wiring harness on? Could this be what's causing the problem? If so, Which lead do I leave on? The one hooked to the chasis wiring or the one going to the TPI ECM?