Hey guys.

Noticed while driving my 93 f250 that it runs a bit rough while using the front tank, but the back tank runs like a raped ape.

Logic tells me that if the front fuel pump was bad the truck couldn't run at all, however if the selector valve is going out this may be the cause.

Any thoughts or advice?

Thanks,
Pose

 

No selector valves on these trucks after 1989, so it's most likely the pump or the wiring leading to it, a corroded ground will reduce voltage and the pump will have trouble as a result.

 

You may have a bad Fuel Delivery Module (FDM) in the REAR tank.
Does the rear tank fill while driving on the front tank?

 

Not at all. If anything, I think I noticed the opposite (rear filling front)

 

Then you have a bad front Fuel Delivery Module (FDM).

The FDM:


/

 

This is the diagram of the in-tank fuel pump assembly, correct?

 

Yes it is from 1990 - ~1996.

 

1993 f250 5.8l My rear tank fills when running on the front tank. what do I need to fix in wich tank thanks

 

You need to change the rear FDM.

 

I know I'm kinda resurrecting an old thread, but considering the variety of FDM manufacturers out there, which ones are better? I'm looking at installing a Bosch 67000 unit in my front tank to fix the pressure and filling issues.

Thanks

 

I bet you $10 that it's the forward in-tank fuel pump. If its producing low press, then....

David

88 F150

 

im having the same problem with my 88 the front tank runs great when i have it switched to the rear it runs like it is running out of gas and on top of that it is using the fuel from the front tank

 

You have a different fuel system then the 93 in this thread.
Check to see if your rear boost pump in the tank runs when you switch to the rear tank.

 

yea my boost pump is working I got under there and started checking all lines for any kinks or something out of place and it all looks good from what i can tell

 

just replaced my front tank fuel pump. Expensive!