Trouble with front tank

[northernleitz]

Got a '95 F150 supercab 4wd with dual tanks. I was told when I bought it that the front tank didn't work. I switched it to the front tank with the key on but engine not running and heard the pump kick on, so I decided to run it. It ran fine for a while (bearing in mind the gas had been in there for 3+ years) but now has very little power. It still idles smoothly, but if I want to accelerate or go up a hill, the engine sputters and sometimes stalls. If I switch to the rear tank, the engine instantly runs better, leading me to believe there is a flow problem when I run on the front tank, but I am not sure. I dumped some Seafoam in there and noticed that the little flapper in the fill hose is bent. I've heard that it could be a vent or return line problem, but it doesn't seem to be pumping fuel to the rear tank and there aren't any leaks from over-pressurization. Would a clogged strainer cause this? Does the front tank use a different filter or the same filter as the rear tank? Any help greatly appreciated.

 

[krafty]

sounds like the low pressure pump in the tank is going out the door. each tank should have a low pressure pump in the tank with a shared fuel reservoir that then goes to the high pressure pump and the filter is between the high pressure pump and the fuel rail.

 

[pvhammons]

I wouldn't dismiss the age of the gas in your front tank. Today's gas seems s to go to "varnish" much faster than older stuff. Maybe it's the Ethanol? I had similar problems and had to drop the tank. The pump screen was almost totally gummed up and the pump was very questionable. The tank had a lot of loose debris and rust. I cleaned the tank and installed a new pump. Working great now.