Hi fellas -- I've read thru all the fuel pump/dual-tank/fuel problem threads and they were helpful in that they caused me to check some things I had overlooked. But my problem is not quite covered by the existing threads, so I've started a new one. Here goes...

1994 F-150 XL 4.9L I-6 Long bed bought new, now has 111,300 miles.

When I switch to the front tank using the dash selector swt, the engine quits. She runs fine on the rear tank. This started 4 days ago.

I checked the FUEL PUMP RELAY COIL fuse, the FUEL PUMP FEED fuse, and swapped the FUEL PUMP RELAY. No joy (and yes, both tanks have fuel :- )

HOWEVER, with the ignition ON, I can hear both fuel pumps as I select them with the dash switch.

1) Am I correct that both fuel pumps are OK?
2) What should I check next?

- h52

 

Whens the last time you changed your fuel filter?

 

Thanks for your reply, Jchubb01.

It was changed 32,000 miles ago.

In my defense I should add that I NEVER let the fuel level go below the 1/4 tank point -- in either tank.

Is there a fuel filter for EACH tank?

- h52

 

You need to do a pressure check on the front pump, just because its running doesn't mean it's pumping fuel.
Could be a hole in the supply tube letting it pump the fuel back into the tank or the pump itself is bad.
No only one filter on the frame with a strainer on the pumps in the tanks.

 

Thanks Nitehawkjr.

Is a pressure test something I can do myself? If so, what equipment do I need?

- h52

 

Yeah it not that hard to do they make a kit which has a gauge, hose and fitting that will connect to the valve on your fuel rail at the motor.
Or you can rent one at Autozone.

 

Thanks Nitehawkjr. I'll check out that kit and report back.

- h52