I have a 95 k2500 6.5 turbo vin f. And since I have owned the truck I have had a skipping/surging problem on heavy acceleration and up hill. And list of mods to the truck are as followed: full four inch exhaust and three inch downpipe. Remote pmd. Cold air intake. Turbo master with illimination belt. And full gauges. What I have replaced is: boost solenoid. Map sensor. Fuel tank sending unit and lines. New lift pump. New ops sensor. New fuel filter. And after replacing fuel system had no serging. For a couple of days and now its back. The truck has 130k and at 110k injection pump was replaced by previous owner and when serging truck does not smoke or lose boost pressure.