My knowledge of injection pumps is pretty limited. From what I know, theres a "metering" screw on pretty much all pumps that determines the rate at which fuel flow will increase proportional to throttle input. (does that make sense?) If you were to monkey with that screw, the pump will allow more fuel flow to compensate for altitude, timing setups, and/or positive manifold pressure. I've only been learning about diesels since I bought my Ford in October of last year, so don't quote me on any of this....all I really know is that diesels are cool. They're cooler with a turbo, and coolest when they haul ass AND dump black smoke outta the pipe!
Ryan