can this happen in the 1988 f150 dual fuel systems

 

Hi, maybe you can start a new tread. 1987 to 1989 have the same parts. 1990 and on don't have a fuel selector valve, but a bad in tank (fdm) fuel pump in either tank can cause this problem to. With a 1988 a bad fuel selector can cross flow between tanks and/ or over flow. I had only a cross flow problem only on my 87 F150. I believe there's a recall for 1989 under...1989 ford fuel recall .. replacing a bad fuel selector value. Its located under the drivers seat in the frame rail. Are you having an overflowing problem? If so, be careful when opening the gas caps, you may get sprayed by fuel.

 

have 89 f250 with overflow problem. am going to try to replace fuel selector valve. where can i find a diagram?