Strange fuel pump

Reply Subscribe

Thread Tools

Search this Thread

Nov 26, 2006 | 10:17 AM

truckin47

Thread Starter

New User

Joined: Nov 2006

Posts: 10

Likes: 0

Strange fuel pump

First let me thank all the people who share this information. I have a 95 F-150 6cyl. auto. with duel tanks.The thing is that the front one only works when the rear is low. I don't know if there is a re-set for that pump but I read a tag on the front that said if it failed to start check the owners man. but I don't have it and don't know where to look . Any help would be appreciated thanks

Nov 28, 2006 | 07:13 PM

dv_shane

Junior User

Joined: Feb 2006

Posts: 70

Likes: 0

try reseting the fuel pump inertia switch behind pass side kick panel has a button on top of it push it and see if that works.

i took that switch out of mine due to it tripping all the time well every time someone shuts the door to hard.
or could be fuel pump relay or pump

Nov 29, 2006 | 07:42 AM

subford

Fleet Owner

Joined: Aug 2005

Posts: 23,667

Likes: 301

From: Easton,Ks

Quote:

Originally Posted by truckin47

I know that you believe the fuel system is doing what you said but it can not happen that way.

The front pump has no idea how much fuel is in the rear tank.
Both fuel pumps are on the same relays, fuel filter and inertia switch so if one pump runs OK they are OK.

You may have a problem with the selector switch or the pump in the front tank may be bad or have bad wiring.

I was trying to think of a scenario with the check and shuttle valves in the FDM to cause this but could not come up with one.

Last edited by subford; Nov 29, 2006 at 07:45 AM.

Nov 29, 2006 | 10:08 AM

truckin47

Thread Starter

New User

Joined: Nov 2006

Posts: 10

Likes: 0

Bill thanks for your response. You are right about the pumps I'm sure. Yesterday I switch tanks just to see what would happen, and sure enough the truck continued to run with both tanks full so I kept the front tank on until I had to stop and when I did the motor stalled. I tried to start it up but it wouldn't start until I switched back to the rear tank. I do now know that it won't start on the front tank but it will run on the front tank when it has a mind to. Could it be as simple as the switch ? I'm not at all knowledgeable about computer operated cars and have read about obd codes but don't know if the 95 has obd I or II or even something differant .

Nov 29, 2006 | 10:19 AM

subford

Fleet Owner

Joined: Aug 2005

Posts: 23,667

Likes: 301

From: Easton,Ks

The 95 has OBD I system.
Sound like you have a bad FDM (fuel pump) in your front tank but it could be the switch or wiring but I doubt it.

Nov 29, 2006 | 11:40 AM

truckin47

Thread Starter

New User

Joined: Nov 2006

Posts: 10

Likes: 0

Thanks for local of inertia switch Shane I found it to be working . Bill thank you also would you mind telling me what a FDM is and where to look for it how to check or change it drop by and give me a hand.

Nov 29, 2006 | 12:21 PM

subford

Fleet Owner

Joined: Aug 2005

Posts: 23,667

Likes: 301

From: Easton,Ks

Quote:

Originally Posted by truckin47

The FDM is the Fuel Delivery Module in your fuel tank.
The best way to change it is to take off the bed and then take it out of the front tank.
SC is a little far from Kansas to go unless you want to pay my RV gas both ways.

Here is a diagram:
http://i54.photobucket.com/albums/g9...yAssembly2.gif