I have 1 91 F150 with dual gas tanks. When I turn the key to the on position I hear the fuel pump prime like it should, the only problem is that it does not turn off after a few seconds like it should. When I switch back and forth between tanks I can hear it switching fuel pumps, but whichever one is selected runs continuously. The truck will still start, but it runs very rough and dies quickly unless I keep my foot on the gas. The check engine light is on but I have not wanted to risk messing something up by driving it somewhere to be looked at. I replaced the fuel pump relay, needless to say, that did not fix the problem. What should I do?
Jan 29, 2010 at 2:38 PM