OK i have a 88 f150 with the 4.9. My truck has set for around 4 years becouse it needed a ton of work. Any way i got it running the other day (cool). And then it lost all of its fuel to the pump. My dad set in to figure it out and he found what we think to be the tank selector valve is sticking in between tanks and cutting off the fuel supply.
He took it apart thinking it could be cleaned and couldnt really do any thing with it so he rigged it up to run on the front tank for the time.
Any way this thing is a big black plastic part that is around 4 inches wide and had two lines from each tank running in to it and one out to the pump and one in from the fuel return line of the fuel rail. and it has a filter like thing on the bottom. It has clips on all the lines just like waht the fuel filter has.
What he cant figure out is how this thing works, it has no wires running to it, if any thing it is operated off of vacume. Now can any one give me a part number for it, i have looked at all the ford parts places online and have found nothing. Or could i some how make one from JC whitney work, i know they runn off electric but a little wireing is no problem.

i hope my description is good enough i am going by what my dad has told me over the phone.

Thanks for any info.

 

If it sat for 4 years the fuel is probably all varnished up in the lines. That is a solenoid valve that switches when you move the tank sel switch (it's electric). It may be sticking from gummed up old gas.

 

How could it be electric if it has no wires to it?

 

Its supposed to have wires going to it. If you don't look underneath the truck for the connector hanging off the wiring harness.

 

CORRECTION that is not a solenoid valve and is NOT electric. I just had the same prob with an 89 F-150, 302 dual tanks. If you look in the Haynes manual it is called a dual function diverter valve. It has 6 lines; 2 for the rear tank, 2 for the front tank and 2 going up front(1 of each set of lines is the fuel supply and the other is the return to the tank). These stupid trucks have 3 fuel pumps 1 low press pump in each tank and the high press pump on the frame rail just forward of the diverter valve. The tank sel switch just energizes the front or rear fuel pump then the fuel pressure operates the the diverter valve. There's is a procedure in the Haynes for testing the fuel pumps by keeping them running for more than just a couple seconds so you can figure out which one is bad. If your dad messed with the diverter valve then that might need replaced now too.

 

The part number is f1uz-9b263-b I recall it's around $70.00.

When the in tank pump builds pressure, it forces the selector
valve so the the proper fuel path connections are made. Output from the proper tank connects with the main pump and the return
fuel goes to the proper tank. The valve is all mechanical.

 

So could you be saying that i may have a fuel pump out or it may just be that the valve goofed up on from sitting so long.

Bye the way thanks for the great info.

 

You can disconnect the fuel hose before it goes into
the main fuel pump. That's the pump mounted on the
frame rail. Place a bucket to catch any gas and turn the
key on and off. See how much gas comes out. Do
that to both tanks and compare the volume flow.

You can also disconnect the hoses before they go into
the selector valve to check for fuel flow. The in tank pumps
do go bad quite often. Note each tank has two hoses. One
for output from the tank and one for fuel return.

Some one on this board mentioned they took a selector
valve apart and could not put it back together properly.