Also thinking about it, might want to make sure your fuel lines are clear. Truck been sitting maybe some crap , rust what have you may entered the fuel line. On a harbor boat I once worked on it had 3 6-71 detroits. one of them fuel problems. Ended up being the spray top from a spray paint can or either can, how the heck it would of got in the fuel tank who knows, but it entered the fuel line and created a partial blockage.