97 PSD IPR problem?
my 97 f250 started stalling while it was idling, but it would start right up again, now it wont start. i replaced the cps, still no start. i removed the ipr valve, the coil is good and the valve seems to be ok. the pcm is not switching the negative side of the coil to ground. i jumpered the negative side to ground and the truck started. i took it to a shop to have it scanned. the high pressure oil is at 725 psi at idle, but zero while trying to start with the ipr wired to the pcm. i measured the frequency at the ipr connector with the key on, it was zero, there is 12 volts to ground, but 0 volts to the B wire. i traced the wires to the pcm connector, all are good. do i need a new pcm? or is there another issue i am overlooking? should i read the 400hz frequency at the ipr with the key on? i was reading 45hz with the truck idling with the ipr ground shorted.