What's wrong with this van?

Recently, an oil line came loose from the radiator (oil cooler) and the van was ran dry of oil, or until a shut-off switch kicked on, i'm not sure which. The van was then towed to a friends house and new oil was put in, the line was replaced, and eventually the van was running again, after the battery was charged. Then a rough, for lack of a better term, idle was noticed. and by this i mean it was almost like the engine was misfiring. the van could drive and the 'misfire', if that's what it was, got worse at higher rpm's (there is no tachometer on the van for confirmation). Eventually a code reader was used and i was not present at this time but i was told that the code reader came up with a camshaft code, so my dad (a mechanic for some years previously) thought that it was the camshaft position sensor. I replaced said sensor (which showed some wear), and that fixed the idle. So to reiterate, the idle is fine on the van now. But if the accelerator is depressed at all, so the rpm's are increased, the engine starts to do odd things, such as shake, and it seems like the engine revs up, cuts off for a second, then continues, much like a misfire. So i pulled the wires for each cylinder, (the wires i pulled were straight off the distributor due to the hard to reach position of the engine) and each and every wire pulled caused a change in the idle of the engine. The van will drive, but it doesn't like to, and the problem only arises at anything higher than an idle. The van is a 1999 chevy astro van, with 137xxx miles on the body and 43xxx on the engine. When the oil line came loose, oil was sprayed all around the engine compartment. Any comments or suggestions would be appreciated.