My (new to me) 1995 5.0L F150 will not run on the front tank. When I bought it from my son he said that he just was using the front tank a month or so ago but had switched to the rear when the front went low. I filled up the front (fuel gauge works) but the truck will not start. Flip the switch back to the rear and it fires right up. Am I correct in thinking that the pump in the front tank is bad? It's weird because my son said that he was just running on it.

 

Try this. With your truck off select front tank and check if the front tank pump runs. If it doesn't or it is very weak it probably doens't have enough pressure therefore truck won't start. What if you start your truck with the rear tank and change it to front. Will it try to stay running?

 

I cannot hear the pump run at key up with the switch set to front. With the switch set to rear I can hear a pump run. If I switch it while it's running it will run for a few seconds (fuel still in the line) then die.

 

But you said it was running... maybe it's an electrical problem rather than the pump going out. I'm not sure that when the switch goes out both pumps don't run or just one of the two tanks stops working. Hey forgive but I am having a wisdom tooth extraction and I might not get on but i'll try. Hope someone else chips in though.

 

The '95 F-150 had some sort of switching valve problem between the two tanks. I remember installing a wiring harness fix at one point that went quite smoothly with the bed off: search this forum for threads on Dual Tank problems or repairs

 

More than likely the front pump is bad, that is the they quit most of the time.