1990 F-150 with dual tanks. The front tank hasn't worked in years, he says. The back tanks fuel pump runs and stops but isn't pushing any fuel thru the un-hooked fuel line at the filter. Needless to say the truck won't start. Can I put an inline fuel pump in the fuel line and not drop the rear tank. How much fuel pressure is required ? Switch valve, how does that work. He said he had that replaced. Thanks for any help.

 

If you have fuel injection you need an in-tank pump because they pump more pressure for the fuel injection. The switch should be on the dash to change tanks.

 

thanks for the reply.
The switch is on the dash, but on the other end of the wire isn' therea valve (?) That is what I was wondering, how did it work. Could the tank switching valve be bad. Is there a pump in each tank? With the fuel filter unhooked on the tank side, there isn't any fuel coming out when the engine is cranked over. Pump? Switching Valve? Thanks.

 

Yes. There's a switching valve and each tank has a pump (if it's fuel injected)- but only the switching valve and one pump have to work for it to run.

 

Thanks , goinstrong,ordered pump for rear tank today.

 

It's good to replace both fuel filters along with it. One's ON the in-tank pump (dirt screen filter) and one's in the fuel line (usually near the tank).