I recently purchased a 1990 F150 Standard Cab LongBox 4X4 XLT Lariat with the 4.9 and eod trans. The truck has 120000 on it and looks like new with the exception of a few rust bubbles on the rear fenders and a small bit on the corners. The only problem is that when you switch to the front tank, the truck stalls and the fuel guage pins itself way past the full mark. Is this a fuel pump problem or perhaps the switch? Also, the truck is loaded but does not have a trip odometer. I found that very odd.
Thanks,
FatParrot

1990 Ford F150 4X4 XLT
1998 Ford Windstar GL
1958 Ford Fairlane 500 Skyliner
1998 Honda Shadow Aero

 

I had a similar problem with an '87 I once had, and it was one of the pumps. Because each tank has a pump inside, you have to drop the tank to change the bad one. I just got a whole tank assembly from a junk yard and swapped it out rather than screw with removing the float/pump assembly. Check the switch first though, cause its a lot easier to deal with.

 

when one of the pumps in my 93 lighning broke it did not max the gauge out like you described so i would check the switch first, sounds like a short somewhere.

 

mine does, the pump in my front tank doesnt work and if i flip the switch to the front tank the needle maxes out to the full side

 

Probably the pump, My 90 I-6 4.9 EFI 4X4 AT has had no probs with that, even with 127,00 on the clock.
You're lucky, I've got major rot on my box fenders, and the "peeling paint problem". But then I live in Wis.