If you do have a 2-second pulse, then the PCM is sending power to the relay coil to energize it. If the pump still isn't turning on and the relay is good, and the secondary side of the relay is getting power, then that leaves a faulty ground to the primary. It will be a black wire/white tracer that attaches to the lower right sides of the engine.
I looked at the schematic again, and I noticed there is a splice. Check for continuity to ground and wiggle that ground (black/white) wire around to see if you are losing ground. The splice may be corroded or coming apart causing a weak ground.
It's a theory at this point, but the other things seem to be working properly.
Let me know.
Friday, June 10th, 2022 AT 8:28 PM