OT - F250 Question
 

We have a 97 F250 w/ the 5.7L and front and rear fuel tanks.

Regardless of the fuel tank switch position, when the truck is hot, raw gas is pumped out of the front filler neck. We siphoned out 5 gallons from the front tank, switched to the rear tank, and still gas comes out of the front tank filler.

What sayeth the PPOT brain trust?

I wonder what kind of pressure relief valve the tank has? On EFI there's always fuel being pumped back to the tank, I wonder if it's pumped back to the front tank only? Gas being pumped in, plugged pressure relief valve, eventually it could spew out the gas when the pressure overcomes the seal. Just a thought.

Leave the cap off of the front tank and drive for a while, see what happens.