I've got a truck that puzzels me. At least once every ignition cycle it will bogg down under any load ie; raising the mast, forward travel, sometimes revving it with park brake engaged. At the same time it'll smoke black out of the stack heavily. If I hold it there it'll smother out and die. If I let off (let it idle half a second) It'll run just like it's suppose to. Usually the rest of that Ig cycle. Thing is when I unplug the vacuum from the EGR it runs great, never misses a beat.
Things that have been done,
2000 hr PM(t-belt, all filters, etc.)
New EGR valve
Turbo(Preventitive due to unnecessary impeller slack, Intake hose off long period)
Updated turbo intake hose.

Any help greatly appreciated.