pagmanofidaho

Looking for some help Please. I have a 94 F150 Dual tanks, 5.0 Automatic 4WD. My rear tank works fine, but the front seems to have a problem. When on the front tank the gauge gets lazy or doesn't work. Example; With tank partial full or totally full, over a 100 mile trip it will stay on empty for about thirty miles or so and then it will start rising towards full, it might make it or it might stop half way, but never the same thing. any ideas appreciated. Bought truck used from original owner and he had the same problem for a while. Thanks for looking.

fltdriver

Probably the sensor/sending unit on the front tank, replacing it is basically your only solution.

ToddsSS

My daughter's 91 2WD was having two issues - when running off the rear tank the return fuel was being routed to the front tank and the fuel gauge was on E 90% of the time, occasionally your would see it move up to around 1/4 of a tank. I purchased/installed a replacement pump and sending unit assembly and everything is fine now. When I dropped the tank and pulled the sending unit I found the brass float had cracked and was about 3/4 full of fuel. I think a new float would have fixed the sending unit but not the check-valve issue.
These floats are still available so if your only issue if the sending unit might be worth a try checking the float.