Cummins NTC 400 Big Cam 3

[DLC]

Have all the rubber fuel lines ever been changed? They deteriorate over time and suck air but won't leak fuel. BC3 will have static timing and no STC. White smoke usually comes from retarded timing on these engines. Once they warm up the smoke goes away.

Premco makes very good injectors for 855s. My brothers truck was acting similar. He had PT pump sent away for a rebuild. Solved problem. Not hard to remove pump. Often the seals go bad inside the pump. New seals are bio diesel USLD compatible.

Add duel fuel line kit to the engine. 25 HP more and 1/4 mpg better fuel efficiency.

Good luck.