Originally Posted by
helo
REALLY check your 5v wires? 7427/8625 pins A14, B2, E14, F9, F14 (others??)
5v is used for TPS & map (duh), but also for OBD and ICM !!!!
Hmm? More important, the ICM __MUST__ have good ground. This is a huge shortcoming with factory setup, because ground comes from intake manifold through the distributor hold-down clip, to ICM mounted to distributor base. Overkill fix is drill 1/4" hole in dizzy base and run a ground wire with ring terminals, super-overkill is relocate ICM onto grounded heatsink and splice the pickup coil wires & coil wiring to reach..
To me, this sounds like your pickup coil signal is not making it to ICM, or ICM is not sending the 5v square wave signal to PCM (because ICM does not have GND or 5v), so PCM never knows engine is turning. Not connecting via OBD seems odd, though..
I expect some sort of issue with the 5v wires.