Cargo Van Troubles

[montanamike12]

just bought a 1996 Chevy c20 van (G2500 is what the part stores look it up under). It has a 4.3L engine. I'm in the middle of tuning it up because i'm not sure how it was taken care of before i purchased it. It has 220,000 miles on it now, which i understand to be original. My problem is that it has now power when traveling uphill. Also on flat ground it is slow to come up to speed, kinda chugging away, but it seems to purr once you get it there. Say at 35-50mph you barley have to touch the gas pedal. I've changed the fuel filter, spark plugs, ran injector cleaner through the system.... was thinking about using sea foam? Also it kind of lurches when you come to a stop light... sort of like it wants to jump off the line... or sputtering, it doesn't seem like it's misfiring but it kinda shakes like it is at a stop. Thats all i have for now Please help!

[jro909]

fuel pump..fuel pressure regulator..could be alot of things the TB could be dirty...check for codes

[asc08]

Bad Cat? As JRO suggested, any codes coming up?