Troubleshooting Backfire, Rough Running, Exhaust Popping

[Alex3000gt]

1991 Stealth ES. MTX, the wife's blue one - not mine.

Check Engine light is on, Pulled codes 41 (Fuel Injector Circuit) and 15 (TPS). If I clear the codes, code 41 returns within a minute and is stored in memory.

I used the datogger, MMCD, and determined that the TPS is functioning fine. Reads 15% at closed throttle and 95% at WOT.

Checked resistances on all fuel injector terminals, all were the same.

Where should I begin?

[Alex3000gt]

Verified all of the connections were snug, and while doing that found an unrelated issue - that the oil pressure wire was frayed. Fixed that.


Eventually ended up swapping out the ECU for a known good one and the car runs amazing now. Throttle is responsive, no more cloud of smoke behind the car, popping in the exhaust is gone. Best yet, the check engine light is gone and no codes came up after driving around for a while.

Looks like this car is another victim of the leaking capacitors on the ECU board that first gen cars are known to have.

[Turbo Beast]

Haha solved!

[Alex3000gt]

Haha solved!

Yep!! I feel a bit silly for asking then solving it myself a day later. I will keep the thread here in an effort to build the amount of useful information on 3SGTO.

Hopefully someone finds this thread a year from now and it helps them.