Fuel Tank Problem

[KEYS88]

I have an ongoing problem with the dual fuel tanks on my 1995 F150.

It seems the fuel is being pumped from the rear tank into the front tank. When both tanks are full, the fuel gushes out and overflows, I've never seen anything like it.

The trouble started with the rear tank being the only one I could run on, the front tank didn't work at all, it would simply choke out, almost like it wasn't getting enough fuel, or as if there was air in the line.

I spent $327 on a new fuel pump, and this worked for awhile, but now the problem is reversed, it won't run off the rear tank and chokes out the same way.

I've taken to keeping about 10 gallons in each tank, because it's pumping fuel slowly into the front tank, you can actually watch the guage go UP the longer you drive!!

Anyway, it seems to work OK for about the first 30 minutes I drive, then it starts acting up without fail, as if something gets hot. I do hear a vibration, sort of like a hum, seems to be right behind my seat almost, and I did read somewhere that there is a third power pump of some sort below the driver's seat.

It does fairly good on the open road, but once you get into stop and go situations, it constantly sputters and cuts out. It will generally stay running in neutral, but bogs down after I put it in gear. The engine runs fabulously, I don't seem to have any other mechanical problems.

Any ideas?

[tbenton]

Back tank stopped working 2 years ago so decided to just get over it and use front tank. Just had complete overhaul and included was injector cleaning,etc. Last week engine light came on and it kept stalling like it was flooded and then would not run at all. Had to have it towed to dealer and they said needed front fuel pump. Then they called and said all of a sudden back pump/tank started working so I decided to just deal with it and switched to back tank. Three days ago same thing started happening with back tank except this time could not get power to go over 35mph with sputtering,etc like it was going to stall again. Hope we get some expert advice.

Leaning toward getting one new fuel pump on front tank but after reading your post am concerned if this will fix it.

[ModMech]

It seems like the fuel tank switchover solenoid is not closing allowing fuel to be returned to the wrong tank, and posibally restricting the flow of pressureized fuel to the engine.

On your '95, you have only the two pumps, one for each tank, and a switchover valve on the frame near the back of the cab. This valve directs fuel to/from the selected tank. Clearly the dash switch is working.

Also check for bad tank vents by running with the fill cap loose (not off, but loose), so the tank can easily vent thru it.

[w8crz]

I just got done checking recalls on my 91 and it had some check valve that went bad and causing the fuel to reenter the other tank and ofcourse if it is full causing an overflow. You might check to see if you have them and check them out.

[jeepsterjayson]

Yeah this was a post about two monthes ago. Samething was happining, I have a 92' F-150 in 98' I got a notice that there was a recall on the switch and I thought nuthing of it a year later fuel was being pumped on the ground out the front take. I took it to the dealer and they told me it was already done because there was nuthing pulling up under my VIN. I had to convice them that it wasn't by going to the gas station and parking in their lot. It was free for me and only lost a few gallons of gas and pissed off a mech. who had to drop the front tank to get to the switch.

[bikermoose]

I have an 87 with two tanks and there are three fuel pumps one in each tank that are low pressure and the main on the frame rail that is high pressure check and make sure that that one is working