Hi Paul, yes, I've been pouring over this thread as well as two other threads on this topic (
Gen 3 coyote fuel pump not getting power and
no start condition on coyote) and verified I've done everything correctly and checked the grounds, fuel pump, and continuity between multiple points in the system from the ON switch to the pigtail. The behaviour I'm seeing suggests the ECU isn't doing what Ford claims it should do. The behaviour I'm seeing is identical what Mike Everson described in
post #24 on this thread:
Ignition LOW, start LOW: System is asleep. Nothing happens.
Ignition HIGH, start LOW: ECU wakes up (verified because the throttle body initializes and pushing the pedal opens the butterfly valve) but fuel pump stays OFF.
Ignition LOW, start HIGH: nothing happens. Same as LOW LOW above.
Ignition HIGH, start HIGH: Fuel pump and Starter motor signal turns ON for almost exactly 1 second before both turning off.
This behaviour is different from what ford described in
document IS-1850-0625 (Instruction manual for the g control pack). Point 6.2.1 on page 14 of 23 states that the fuel pump should turn on as soon as when Ignition become HIGH, and will turn off after a few seconds. In my case, it does not come on at all when ignition is HIGH. It will only come on when both ignition and start are both HIGH, in which case the pump and starter motor signal turn on for 1 second and then turn back off.
What I'm trying to figure out is why my ECU isn't doing what the manual says it should do.