I'm betting you have a bad line. Mine did the same thing, installed draw straw and replaced all the lines with diesel approved rubber no problems since.

 

i've already replaced the lines with new rubber ones. and the air pocket is closer to the motor then the tank it will run and start great for about 15 sec roughly then stall out. only when the truck is parked on a grade where the front of the truck is higher then the rest of the truck. Im going to delete the fuel heater and see if this helps.

 

ANyone got a diagram for the overflow valve? i am experience some air problems after having a severely blocked pre filter. I will delete the heater tommorow, theni needot have aa look at the OFV but don;t have a clue where it is...Pictures please