is the VP dying?
 

My buddies truck, a 2000 5 speed with about 100k on it started jerking. when you get cruising about 35-40 in 4th gear it feels like someone has a chain hooked to you and jerks you back words. i have heard this could be the injection pump. stock lift pump and a superchip d box is all it has. so after i heard about the stock lift pump, all i saw were dollar signs he was about to spend.

any ideas, is it vp or something else?...

when this happens does the tach go to zero

no not that i saw. i forgot too, it seems to smoke ALOT shifting from 3rd to 4th for only a 60 horse chip. unless it being a manual has something to do with that. my trucks auto so not sure

if the tack goes to zero than the cam sensor is kaputski

ya i did that on my truck. he doesnt show any codes. we were going to try adjusting the apps and see what happens sense thats a free fix and check