Fuel problem???

Hey guys....Can anybody help me out...I'm stumped...
Own a '79 F-100, I had duel tanks on it,but took the rear one off because of rust in the tank.I'm having a problem with it running out of fuel at the carberator.
I'll be driving along and it will quits on me.So I have to take the fuel line off at the carberator,turn over the engine so the fuel fills the line.
I've replaced the fuel pump and fuel line.I took out the sending unit inside the gas tank to see if that was plugged up.
Nothing seems to help.Anyone have any suggestions?
Keith :banghead:

Keith, start by capping off the line to the tank you removed with a blind cap at the valve (use teflon tape on threads). Sounds like you're getting air in the line also, check the gas tank top to make sure it's not leaking. Maybe I'm wrong but, some of the fuel tanks have to be pressurized before the system works properly.

ervinj