I have been reading different posts and wanted help in figuring out my problem.

1989 F250 7.5L with a fuel tank switching issue and neither fuel gauge works. With no power, the rear tank shows maybe a 1/4 but when power is applied reads empty. The front tank doesn't move.

Also,

Truck currently runs off rear tank only, front tank does not work, truck dies when selected. I know the fuel selector switch works, so my next thought is the fuel selector valve/dual tank reservoir? It looks to be mechanical, no electrical switch?

Describing the fuel gauge issue and selector issues, does this sound like the valve? If so, how do I remove fuel lines, do I just remove the push tabs that lock and pull off the fuel lines?

Thanks.

 

when you select the front tank and turn the key to the run position can you hear the fuel pump priming (buzz for 2-3 seconds)

 

Yes, I tried that and I can hear the front tank priming.

 

How do you know that?


Could be but you need to make some test.


Yes it is mechanical valve with on power to it.

Could be but you need to make some test.


Yes that is about it.


When you go to pull the lines off mark the location so you can put them back on in the right place.
Get a bucket and a old fuel pump vacuum gauge.
Take the larger fuel line off going into the valve from the tank that does not work and stick it in a bucket. Ground pin #6 of the EEC self-test connector and turn on the key. If fuel pumps out of the hose turn off the key and hook the fuel pump vacuum gauge to the hose. Turn on the key and see if you get 5-7 PSI fuel pressure. If so it does not look good for the valve. If you do not have the fuel pressure and you can hear the pump run you will have to drop the tank or remove the bed. It may be a bad pump or a bad hose in the tank.

 

Hey All. I have a 1988 Ford F-350, crew cab dually. For some reason my forward gas tank isn't working. I've replaced both the internal and external pumps. I can hear them when I turn on the ignition and the guage does register the amount of fuel when I use the in cab selector switch. My last thought is the selector valve. My manual doesn't give the location. I see the resovoir where all the lines (6) are located but not the valve. Are they one in the same? Any help is welcome.
Sam

 

Yes they are one in the same.