My 93 flairside won't run off the front tank.
When I turn it to the front tank and turn the key on I can here the pump pressure up, but wont start. The fuel gauge shows the tank to be full, which I can believe since when I run down the road there is gas dripping out the filler cap of the front tank. I'm pretty sure the return line is going to the front tank.

 

If the front tank is overflowing when you run on the rear tank, the shuttle valve in the front FDM is toast. As for "hearing" the pump run, that means nothing. Are you getting pressure at the fuel rail?

 

how do I check for the pressure? I'm not used to this new elect. stuff, gimme a carb. and I can figure it out.

 

There's a test port on the fuel rail with a Schrader valve in it. You need a gauge that adapts to that port. Get a shop manual, it explains.

 

Click the black Bronco in my signature & look in the EFI Fuel Pump album.