Can someone tell me what the hell is goin on on. My front tank will suck gas from the rear tank to the point it is overflowing and building preassure behind the gas cap. What could be the cause of this
I had the same truck back in the 90's. Bought new in 92, sold it in 01. There was a safety recall on those trucks for that problem. It's a bad design/problem with the selector valve that let's you switch from one tank to the other.
The tank is really not sucking from the other. Since the engine is efi it doesn't use all the fuel that is pumped to the engine. The fuel pressure regulator bypasses it back to the tank. It's SUPPOSED to bypass it back to the tank you are using at the time. It's switch is stuck and it's sending all the bypassed fuel to the front tank.
I would have a dealer run the VIN # and see if the recall was ever done. If not, it should be a free repair.
I have a 90 F-150 that does the same thing...... i believe what is happening is when you are running on one tank, when it returns fuel, the tank switch valve is not working correctly and is actually returning the fuel to both tanks,...... If it is only using fuel out of one tank, any time the key is on, you are circulating fuel, at some point the fuel will then all be pumped into the tank you are not using.....
Make any sense ?
I just never felt like replacing the 350.00 (from ford) switch valve in the frame.