BigHungry

How y'all doing? I recently bought a 1995 f150 XL 6 cyl. With dual fuel tanks. I bought the truck knowing of this issue before hand. When running on the rear tank , the truck runs great but burns fuel fast, the guy I purchased from said when running on the rear tank, it fills up front tank also. When I turn the key with it set on the rear tank , I can hear it prime but it will not start until I turn it back off and then back on, to prime again, which will then start . I'm assuming the fuel lines have to be refilled. But the main issue I'm having is when switching to the front tank while running, the truck kills. If I put it on front tank and turn the key, I can hear the front fuel pump prime for 2-3 seconds before trying to crank and it just turns over but doesn't start. If I put it on rear tank and turn the key, I can hear it prime for 2-3 seconds then turn the key and the truck starts. I thought maybe it was a fuel pump issue with the front tank, but I can hear it pump when primming. I also traced out the fuel lines and didn't see any fuel selector valve, just that the fuel lines T in to one another . Any idea of what can be causing the fuel issue with the front tank?

mike100

the front tank fuel pump assembly need replacement. it sounds like it both fails to make pressure and also does not prevent fuel return when running on the rear tank (thus cross-filling). Just replace the front tank pump assembly. Luckily, the front tank is the easiest one to drop.

Steve83

This shows how the fuel lines are run:


(phone app link)

This shows how the FDM works:


(phone app link)

This is why it's transferring fuel:


(phone app link)

Don't buy Airtex or Spectra - they're garbage. MotorCraft is best (of course) but also expen$ive$t. Bosch might be OK.

BigHungry

Ok, I'll see if I can test the pressure and then replace the pump possibly this weekend. I will let you all know. Thank you.

BigHungry

Another question, do y'all think it's easier to drop the tank or remove the bed?

Steve83

Depends on the whole situation. Do you have a way to lift the bed? Do you have a way to lift the truck, or work underneath it? Is it clean underneath? Clean it some more, either way.

Click this & read the NEXT several captions:


(phone app link)

BigHungry

Thank y'all for helping me out, pulled the bed last night and replaced the front pump, truck runs on both fuel tanks now. I was expecting the inside the tank to need cleaning bring it old, but tank looks great.