When we are driving our 96 F250 gasser on the rear tank is sputters and tries to die out. Even with a full tank it runs like it is almost empty. The strange thing is it is sucking fuel from the front tank and over filling. The truck runs fine on the front tank. At first I thought it was the selector valve. I thought it was somehow redirecting fuel into the rear tank due to a malfunction. We even went to the parts store and bought a new one. Well guess what… this truck does not have one. It has a block that all the fuel lines converge into. So I now believe the sending unit in the rear tank is bad. That would explain the sputtering. But how do I explain the removal of fuel from the front tank to the rear?