I asked over on cummins forum awhile back...(ive been dealing with this for about a month now). Few weeks back the raptor fuel pump that the last owner of my truck put in died on me so i swapped it with a fass. Trucks a 96 12v. 191 dvs, 64/71/14 turbo, 5x14 injectors, built trans. Ever since the truck has been nothing but a PITA. Starts hard after sitting, when it starts it idles like crap, cant rev it without it sputtering and missing. Whole truck shakes while idling and i can even drive the thing for a little while. A good amount of white/ blue smoke comes out of the exhaust that stinks of raw fuel to the point where it burns your eyes. Timing has been checked and rechecked and rechecked again, 15.5*. Changed injectors along with all sealing washers and hardware. Injectors are 5x14's. I replaced the return line up to the tank (as close as i can get to it without dropping the tank anyways). Changed fuel filter. My gut is telling me its air getting in the system with it being most problematic after it sits and losses its prime. But i have no clue where the air could be coming from at this point. Fuel heater assembly and pre filter screen crap is al long gone. Can anyone think of anything. Im at the point where im missing work because i cant drive my truck. And honostly id sell it at this point but it wont run good enough to sell