318 Engine stumble
So if the module was hooked up backward. The car would run bad in the upper rpm range?
It probably wouldn't rev at all, and the timing lite would see dropped sparks and erratic timing all over the place.
If you don't know, the Mopar pick-ups are just little signal generators. (They do pretty much exactly what points do with out the hi-rpm bounce, nor the stinking maintenance.And the dwell is maintained better.)
Every time a vane passes by the magnet, it causes a disturbance in it's magnetic field, and the ECU then reads that and tells the coil to fire. But the signal generator creates a signal strength in relation to the coming and going of the vane, with the voltage first rising then falling. If the Ecu is designed to trigger on the rising voltage, then everything is hunky dory. But if the polarity gets reversed so that the ECU is trying to read on the falling side; well you can change the base timing by repositioning the distributor, so it will idle. But as soon as you start increasing the rpm,and the mechanical advance starts coming in, all hell breaks loose, cuz the rotor is waay out of sync. So between those two things occurring simultaneously,it runs pretty crappy off idle. and usually will not rev up very far, and certainly not smoothly. If you are getting a smooth 4500,I'd say your polarity is A-Ok.
I can't speak to the HEI, but I expect it works similarly.
