2 Attachment(s)
No spark from L67 3800 V6
I swapped an L67 3800 from a 2000 Pontiac Bonneville SSEI into a 1984 Mazda RX7. It's fitted to a manual transmission, no air conditioning, no egr, and no evap so I trimmed down the Bonneville engine wiring harness to only have the minimum wires required for engine control, and I am running a random 6 fuse 6 relay box I got from ebay.
I got everything all hooked up and ready to go, but it wouldn't start. Some diagnosing has revealed that there is no spark on any cylinder. It is my understanding that on cranking the ICM is in full control of spark stuff, and in fact it should have spark at cranking even with no PCM at all because the PCM doesn't take over spark until its running.
My initial guess was it was just an issue with my wiring work, so I pulled up this diagram of the wires going into the ICM connector.
Attachment 131502
I verified we have power on pin P, and ground on pin K and M. I only have a one lead scope so I couldn't scope out both the crank 18x and crank sync signals on pins G and H at the same time, but individually they look at least reasonable. I can see the sync signal has three progressively larger windows and the 18x signal looks like a bunch of mostly even blips up and down very quickly.
I figured that with these things it should be capable of getting spark, right? So I swapped in a known good ICM and set of coils packs assuming mine were bad. It didn't fix the issue, still no spark.
Any ideas on what I am missing here?