I have a 1997 3500hd 6.5. It will start and idle. When u try to drive it stalls and u have to bleed air out of the line and it will start back up. Also when u try to put fuel in the tank it backs up and wont take any fuel but its not full its almost empty. When it is idling and you take the fuel cap off it will push fuel out.

 

Sounds like a vent on the tank is plugged