[mjlogan88]

White smoke makes me think headgasket- any signs of coolant loss/overheating? Maybe a compression test will tell you more.

Check the IP timing- these motors are very responsive to timing changes. You'll probably need to have a shop do it unless you have the special tools.

Maybe run a search over at oilburners.net. Pretty good info for these trucks

 

[mjlogan88]

The bad idle happened to a friends Cummins. It ended up being the crank position sensor. He didnt have the smoke though.

No electronics on the IDI trucks. One wire to the IP and thats it