Truck starts hard, smokes misses. after about a minute it runs fine until the next morning 1st start.

Air must be getting into the fuel system. I figure air in / fuel out but I do not see any leaks. Whats the best way to find the air leak? Must be very small as it takes about 24 hrs to have any effect.

 

Tough to find usually, depending on where you live, could be as simple as the rubber lines from engine back to drivers feet, or if you live in the rust belt, could be all the way back to the tank including the fuel module lines.

Most of us eventually just replace the whole thing from engine to tank with diesel rated rubber hose.

My first one was all the way along with a revised fuel module, my Greenie has rubber back to under the drivers seat, I would have went all the way except it was at night and I ran out of hose ( and was to solid steel line finally ).

3/8" feed and 5/16" return hose.

Good source if you want a one stop shop, but more expensive.

Larryb - Dodge Fuel System parts - Dodge Cummins Diesel

If you want to just buy the hose and get the rest yourself.

Hoses - Fuel Hose | MMIMarine.com

3/8" hose
- 365-0386 TRIDENT #365 TRIDENT "BARRIER LINED" TYPE A1-15 MARINE FUEL 3/8 x50 Reel Box | MMIMarine.com

5/16" hose
- 365-0566 TRIDENT #365 TRIDENT "BARRIER LINED" TYPE A1-15 MARINE FUEL 5/16 x50 Reel Box | MMIMarine.com

 

You can pressurize the tank with a few lbs of shop air through the filler neck and a rubber stopper/rag etc (carefully!) and it should show any leaks. Return line on the back of the pump was my culprit.