Mechanics

LOW FUEL PRESSURE

Ford Expedition

I have a 1998 Ford Expedition 5.4, it has 92,600 miles. I have replaced the fuel pump & the fuel filter, I have checked the fuel relay in the distribution box & the fuse. I have disconnected the fuel filter & with the ignation on there is almost no gas coming out of the line. Any suggestions?
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93fordman
January 14, 2007.




Thanks for the donation! : D

What brand of pump did you use?

Was the pump replaced to fix an issue or was this done at an earlier date?

Is this a 4x4?

Does it have air suspension?

Brand is a Master
The pump was replaced two days ago vehicle would not start
4X4 yes
air suspension no
:

Tiny
93fordman
Jan 14, 2007.
Charlie,
My experience is anything electical from Autozone is junk. Based on the TSB, I'd put in the dealer pump. I am real leary of a lot of aftermarket pumps. We have had bad luck with a lot of brands. Chysler ones I always go dealer. Gm -ac delco, Ford I recommend dealer, and don't give a labor warranty if aftermarket is chosen.
I'd drop the tank if you have to and blow air through the line to make sure it isn't plugged and check for proper power flow to the connector. If good use the ford revised pump according to the tsb spec sheet.
PAul

I have found that the volts going to the fuel pump shut-off switch is 12.5 and coming out is 7, does any one have any suggestions : Thanks Charlie

Tiny
93fordman
Jan 17, 2007.
Hey Charlie,
Looks like you've got the problem nailed! Your referring to the inertia switch right? A quick to to verify would be to disconn the switch and jumper the connection and. Viola. Good fuel pressure should return

Chris

Tiny
Carundell
Jan 17, 2007.
Chris I thought so to, I put a jumper and got 12.5 volts so I thinking that it was going to work, put the unit in the tank and hooked everything back up and with the jumper in place it did nothing : this has been a pain. I was talking to Paul and he said you are good at this kind of problems. Do you have any other ideas? Thanks Charlie

My email address is rocker1950@comcast. Net if you don't mine sending me your phone number I will call you.
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Tiny
93fordman
Jan 17, 2007.
Wow, its bein' real pain. Time for some more testing! Have you done voltage tests further down the line? I would go right to the fuel pump connector and test there. Don't forget test test for a good ground also!
Let me know how that goes! Will email ya my biz # if all else fails!

Chris

Tiny
Carundell
Jan 17, 2007.
Yes, with the unit out of the tank and the jumper hooked up I got 12.5 volts at the plug that goes the the fuel pump, when I put it all together the pump did not run

Tiny
93fordman
Jan 17, 2007.
Ok, and you verified a good ground for the fuel pump assy?

Chris

Tiny
Carundell
Jan 17, 2007.
Do you mean when it goes in the tank and locks down?

Tiny
93fordman
Jan 17, 2007.

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