I have a heavily modified 1991 350 TPI and it was running great on Saturday. Monday I popped the memcal out to adjust the startup enrichment and when I put it back in and started the car it ran and drove like crap. Barely started, had to keep on the gas.

What I thought was mechanical turned out to be none of the passenger side injectors firing. The car runs but very poorly. I ran it for 5 minutes and all 4 of the passenger side header tubes were cold. Driver side was hot.

I have re-wrote the PROM with known good working tunes onto 3 different chips with no change. I have swapped ECMs with no change.

I don't have a noid light but rigged a small bulb across the injector connector and when cranking and running the bulb doesn't light up.

Both injector 10amp fuses are good. Power to the pink/black wire at the injector.

Is it the ECM or PROM that controls injector firing? I don't have a separate complete Memcal to try right now.

Any ideas??

 

Probing the injector wire right from the harness at the ECM shows no grounding signal when cranking or running. How can only 1 bank be not working?

 

the ECM has 2 injector drivers. maybe one of them died? try another ECM and see what happens.

 

Check the inj fuses.

 

Found the problem. Taking the ECM out of the dash repeatadly to program the PROM caused the pink/blk injector wire to break inside the coating. Soldered it up and it works like new again.