Did you drain the gas tank yet and rinse it out?? Did you pull the pick up and sending unit? looking for derby on the "sock"? It could be a spark issue, but generally speaking, if it starts and runs - you have spark (although the spark may be weak or stops etc, etc). If it starts and runs, then you stir the gas in the tank and it stops running (the sock gets clogged and stops the truck, sits and sock is no longer clogged and the truck runs.. rinse and repeat)- its a fuel issue. I would REALLY remove the tank from the equation, gas can to fuel line like recommended before, start there and move forward... I had the same issue with my Burban when I first got it.... Move in a back to front motion
Hope it helps.
