On Wednesday, September 18, 2013 11:47:23 PM UTC-4, jim beam wrote:

> > Where is this located?
>
> crank, cam or distributor.


I have a factory service manual, so far haven't found a mention of a TDC (top dead center) sensor. I don't think it's on the cam or crank since I don't recall ever seeing anything like a sensor on either - I'm guessing it's most likely on the distributor.


> have you tested the icm yet?


What's happened since I first posted this - while getting familiarized with the wiring to the ICM, I was nosing around, grabbed and jiggled the harness connector to the coil. Now the car fires up instantly every time and runs smooth as silk as before this issue developed. I can't say for a fact that's what did it but that's the only manipulation I did and it's been running without issue since. Maybe corrosion on the connector reached a critical point and was impeding spark?

It's unclear from the previous input what I'm supposed to do to test the pulse from the ICM. Am I supposed to be able to use the inductive timing light to get a pulse from one of the ICM wires?