truck occasionally won't accept gas. Stalls. Starts right up. Okay til next time. New fuel pump.

Hello, when you say "will sometimes not accept gas" - do you mean filling the tank at a gas station? Or do you mean depressing the accelerator pedal? Engine performance concerns dealing with fuel to air mixture ratios can cause hesitation on acceleration. Testing will need to be performed to look at fuel trims, air flow, and other related data that affects engine performance. Your fuel pump only brings base fuel pressure to the engine, and will not affect fuel delivery to the cylinders if there is ample pressure in the first place.