morriss

I'm stumped. The truck won't start and there is no fuel pressure when cranking, or even when cycling the switch to the ON position a few times in a row. When I put a jumper wire from the battery to the fuel pumps (dual tanks) connections on the tank selector switch, the pumps run and I get 41 and 42 psi, so the pumps are working. I've replaced the fuel pressure regulator (twice), and I have verified that there is no fuel coming out of the top nipple when cranking. I've replace the fuel pump fuses and relay in the fuse box under the hood. What am I missing?

morriss

And I installed new fuel injectors. I realize that is probably downstream of the issue, but figured I add that bit of info as well anyway.

Soup Bean

Did you check the inertia switch, which should be behind the passengers side kick panel?

morriss

Yes, it’s pushed all the way down.

morriss

Forgot to mention..the next day after it would not start the first time, I did get it to start and run for about 10 seconds. It was sputtering and was barely running, and then puttered out. It did not start again after repeated tries. A couple of days later, it did the same thing, and when I pushed on the gas to try and keep it running, it died immediately. It has not started since.

Soup Bean

If you jumper the pins marked "A" and "E" at your diagnostic plug, under the hood, the pump you have selected should run continuously, when you turn the key to the run position.

The fuel pump relay is powered from the PCM relay. I would test for voltage at the fuel pump selector switch and work your way back through the inertia switch and to the fuel pump relay and PCM relay.

morriss

Is the PCM relay the same thing as the electronic engine control relay? I don't see anything in the Owner's Manual called PCM.

morriss

I went ahead and replaced the EEC relay, assuming it is the same as the PCM relay. Still no start. I will replace the inertia switch later today when it stops pouring rain.

I have spent the past 1.5 hours looking for an EEC diode, spot #12 in my picture above. That part # is discontinued (FOVF-14A604-AA) and I can't find a cross reference number for one that IS available anywhere. I called two different Ford dealerships and both told me to go to a junk yard and try to find one.

Soup Bean

Yes, the PCM relay is the same as EEC or ECM.
Do you have a tester to test circuits with? You could be losing the voltage at the fuel tank selector switch, ignition switch or inertia switch.
It's worth the time it would take to test for voltage along the circuits.
Some years, that diode was in the harness. I've never had to change one, but that would be another advantage to testing the circuits. You may not need to change it.

morriss

Put in a new inertia switch, still no start.I turned the ignition switch to the ON position (not START/crank) and put a jumper wire between A&E as suggested, and the pumps did not turn on.


I then took a test light and hooked it up to the battery ground (ignition switch still in the ON position), and touched the shoulders of each and every fuse in both fuse boxes (under dash and under hood) and got nothing.

Faulty ignition switch?