Guys I was down the shore over the weekend and I started up the truck and before I said anything my wife said "OOO your truck sounds weird". OK hopefully by my wording it will describe what it sounds like so you will get the idea.
Start : "CHUGGG A CHUGGGA CHUGGA"(kinda like an old train) put it in Drive "Chugga chuggga chugga" drive for a couple of minutes,back to normal Cummins idle. Return to park it for the evening put it into "park", idles fine

I never had this before!! Does anyone know what this could be?? ???

Thanks for any help!!

 

My 02 did the opposite thing, it wanted to idle at like 1300. Took the cover off the cable under the hood and every thing was at idle position. I had to leave the truck off for two hours and then it was fine. Is the fuel pressure good? What about fuel filter?
Chase

 

Several things come to mind thinking back on different experiences being around diesel engines over the years.

Slight amount of air in the line
a slug of crappy fuel
burnt exhaust valve(s)
improper fuel delivery from injection pump.

Time will tell, if it goes away then most likely 1 or 2 if it keeps up well......

Just not long ago we changed out the injecter pump on a back-hoe that was doing much the same thing you discribe (surging at idle) but it was always there....never went away at all. Totally different beast too. 8)