What can cause my Ford Explorer sport trac to lose power going up hills?

I have the 4.0l

Ok, the 4.0l is known to have issues with the intake manifold gasket, upper gasket and lower sealing rings. They fail all the time, and they will cause a stall when the gas pedal is not pressed because there is not enough fuel to run the engine. turn the truck on and spray water around the intake manifold. It will either change how the engine runs, cause it to stall, or do nothing. If it does nothing, check your fuel pressure. If you get a big change, smoke test the engine. You will likely get smoke out of the intake manifold. seals.

Ok I'll try this..thank you

No problem, let me know if you need anything.