i need help w/ my silverado plz

My 99 5.3L z71 silverado (ls) stalls (losses power) when going up the hill, and wont accelerate right going down the hill, but on plain terrain, it runs like a charm... what could it be?????????????? plz help.

For the engine to loose power, air, fuel or ignition (spark) is being lost or disrupted when you are going up/down hills.

This sounds electrical (loose connection) to me. It could be a fuel pump (in the gas tank) connection and you loose fuel pressure when in the hills.

I would check battery cables and look for anything loose under the hood. I would put a fuel pressure gauge on it and watch the pressure when the problem happens.

//2000CAYukon