so my s13 is being lame. when under load, from about 1000-2500rpm there is this hesitation or lack in power, then 2500/3000rpm hits and its like vtakkkkk.
its progressively gotten worse over the past couple months and i've been ignoring it because its a p.o.s. single cam KA missile car. but now i'm selling it so i'd like it to run a little better than it does to get more dinero out of it.

lately its gotten to the point where if i floor it it will stumble on its face for a second then continue with the blah>vtak.
I feel as though this could be many things, considering how poorly i take care of this car, but a headstart would be appreciated.

tl;dr single cam 240sx runs like a bag of dicks, what else is new.

pic related.