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Trying to take a 1991 chevy caprice pcm into closed loop

  • guafa
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5 years 2 weeks ago #43780 by guafa
Trying to take a 1991 chevy caprice pcm into closed loop was created by guafa
Hello guys.

I have installed and old pcm (actually the whole electrical system) in a restored FJ40 toyota land cruiser (manual 4 speed trans). The truck starts and runs pretty well (idles a little bit higher than normal, due to engine is a 6L instead of V8. Not big deal on that).

I hooked up an old OTC obd1 scanner and all engine PID's looks good. But i noticed the pcm never gets into closed loop.

KOEO or KOER if i jump O2 signal wire to ground, O2 PID doesn't change. I have proved same test with two different PCM with the same result.

The signal which are not connected are transmission's and knock sensor. Assuming the ones which need to get into closed loop are IAT, ECT, MAP, TPS, O2, IAC.

Any comment will be apreciated.

Regards.

BTW. Chevy donor was a 1991 5.0L chevy caprice

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