I have two cars with LT1 engines. A 96 Vette and a 79 Malibu wagon with a 94 z28 LT1 engine trans 4L60e swap.
I’m chasing a mis in the 94 setup. I think it’s random misfire of injectors.
I’m comparing tests on both cars to see differences. On the 94, if I pull the flashing noid light out of the injector harness with engine running and plug it right back in, it no longer flashes. It won’t flash again unless I turn the engine off and back on again. On the 96 I can pull a flashing noid light with engine running and plug it back in and it will begin flashing again immediately even without restart of the engine.
I understand the 94 is ODB1 and the 96 is OBD2. Does this explain the difference? Is it normal operation of the 94 PCM to cease providing ground pulse for an injector that has been unplugged? So I’m assuming the 94 (OBD1) requires an ignition off and restart before the pulse from the PCM will be restored, and the 96 (OBD2) will restore pulse as soon as the injector connection is restored, no restart required?
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