1992 Ford F150 Fuel Pump/Wiring

1992 FORD F-150
64,000 MILES • V8 • 4WD • AUTOMATIC
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ADAMMOTTER
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So I've had this truck for almost 2 years and for the last year it has been giving me random problem after problem. The latest of which is that it simply won't start or it will only "start" with the accelerator to the ground and it is extremely rough. I've replaced the fuel filter, fuel pressure regulator, spark plug wires, spark plugs, fuel pump relay, router and cap. Recently I removed the wiring harness above the front fuel tank to test it and the truck started without it on but once the accelerator is touched it dies. It also dies if I start it with the wires unattached and attach them while running. I don't know what to even test or try to replace anymore. I've been told it is wiring issues by some and the fuel pump by others.
Aug 23, 2010 at 3:51 PM
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JACOBANDNICKOLAS
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Has the check engine light come on? Have you checked fuel pump pressure?
Aug 23, 2010 at 10:21 PM
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ADAMMOTTER
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yes the check engine light is on. and yesterday a friend brought over a fuel pressure tester. we tested both tanks and they both gave off a 40 pressure reading. but once we unplugged the front tank the pressure dropped to nothing and the truck started (from the front tank that is). and we could keep it running as long as we gave it some gas all the while the pressure stayed at 0. but once we switched to the back tank the truck died and the pressure shot right up to 40 again.
Aug 27, 2010 at 9:24 AM
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JACOBANDNICKOLAS
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That is really odd. At 0psi, it shouldn't run. Were you checking the fuel pressure at the fuel rail?
Aug 28, 2010 at 12:36 AM
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ADAMMOTTER
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yep, directly on the fuel rail. even had to record it to show my friends boss because he didn't believe us.
Aug 28, 2010 at 11:41 AM
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JACOBANDNICKOLAS
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I have to say I honestly never saw anything like that. Will it continue to run that way?
Aug 28, 2010 at 10:58 PM
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ADAMMOTTER
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It will run but it isn't drivable by any means.
Sep 7, 2010 at 1:15 PM
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JACOBANDNICKOLAS
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I have to admit... I'm at a loss. I will forward this to a different tech to see if he has any ideas.
Sep 8, 2010 at 6:58 AM
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RASMATAZ
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Check the fuel pump check valve on the rear tank

All Technical Service Bulletins
Information

Number Date Title
93S68 09/01/1993 Recall - Cross Tank Fuel Flow Condition

Some of the affected vehicles may experience a cross tank fuel flow condition due to a damaged check valve in the fuel pump/sender assembly. Fuel may be supplied from one tank and some or all of the unused fuel may be returned to the other tank. Should this occur, the capacity of the receiving tank may be exceeded and fuel may overflow from the filler cap. Fuel spillage in the presence of an ignition source could potentially result in a fire.

To correct this condition, the fuel pressure regulator will be replaced and a check valve will be installed between each fuel supply line and fuel tank.
Sep 8, 2010 at 8:33 AM
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ADAMMOTTER
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ill see what i can do, thanks a bunch.
Sep 8, 2010 at 11:08 PM
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.