Diesel Doctor

[bubba3hd]

have 2000 chevy 1 ton dually, 6.5 turbo diesel. Started cutting out running at a varied idle, up down cough once in a while, when driving,would race, blo smoke, idle faster than normal. changed filter(NAPA) seemed to solve problem for about ten miles. then truck wouldn't exceed 1500 rpm without coughing.
pump and injectors replaced by chevy garage under recall less than 20k, only other mod was 3" exhaust
'what do i start looking for? only codes were for turbo map sensor

[JohnC]

Sounds like either air in the lines going to the injection pump or a problem with the fuel lift pump, or both.