Cm870 starts then shuts off,starts back up with a puff off white smoke and stays runn

[Nilao]

It has fuel in the lines at the isfm, somewhere from the pre-filter to the tank it could be losing prime and forming a bubble. You start the truck and it pulls that bubble through and it hits the main pump and the engine dies from loss of fuel pressure. Once you key on again the lift pump pushed the air on to the return line and it fires back up...could be a problem elsewhere but this is a possibility.