Truck Repair: 97 5.9 cummins, stop screw, screw out

Question
I HAVE A 97' 5.9 CUMMINS AND IT WAS LOOSING PRIME AND HAD A SLIGHT MISS SO I REPLACED THE LIFT PUMP.BUT IT IS STILL LOOSING PRIME AFTER SITTING FOR A WHILE AND IT TRIES TO STALL WHEN I COME TO A STOP,AND THE MISS IS STILL THERE.DO YOU THINK IT IS THE FUEL PUMP AND INJECTORS?

Answer
Loosing prime could also be the return check valve in the fuel pump.Low fuel pressure will cause smoking & low power.Is it idling too low?Data tag says I think 840 RPMS.Check data tag to be sure.To adjust idle speed you need a 10MM wrench.The idle stop screw has a jam nut on the bottom of the pump,loosen it & turn the screw out that the throttle hits when at idle.You can see it better if you move the throttle by hand.