2006 F250 with the 6.0L diesel won't hardly idle out of its parking space when cold. Seems to be missing on a couple of cylinders, runs very rough, but doesn't die.

It seems to run fine at operating temperature.

Where should I start to determine the problem?

 

Moved to the 6.0L Power Stroke Diesel forum.

 

I would start by checking FICM voltage. There's a thread in the tech folder on how to do it. Next I would pull the EGR valve and inspect/clean it. And if you haven't installed the blue spring in the fuel pressure regulator I would do that also. A check of the fuel pressure would verify any issues. Fuel filters could also be suspect if they've been in there awhile (be sure to get the Motorcraft filters). If the temp is cooling off where you are, a switch to 5w40 oil could help (again with the Motorcraft filters). It could also be the fuel injectors having some stiction issues. RevX has been a big help to some members here although it is usuially temporary.
How many miles on yor truck? Any smoke from tailpipe? Any recent work?

 

Truck is nearing 100k miles. No smoke from tail pipe. Changed fuel filters about 6 months ago and drained water separator a couple of weeks ago. Changed oil two weeks ago (Rotella 15w-40 and Motorcraft filter).

I appreciate your feedback and will start looking at some of the things that you mentioned.

 

Also, I have read briefly about fuel injector stiction. If RevX fix is temporary, is the permanent solution to replace the injectors?

 

Unfortunately, yes. Current wisdom is to get the remanufactured units from your Ford dealership. Something like $280 each! (+labor). The idea being those sold to Ford by the reman companies have the best specs. A seal kit is available if you are handy and want to take them apart, I haven't read of many people doing it though. They are available cheaper on e-bay but hard to say what you're getting until you install it. A few aftermarket vendors have them for a little less $ also.
On your truck with just over 100k mi the injectors should have a lot of life left unless the fuel pressure is low and has been for a long time, a cylinder contribution test will point out any bad ones. I would just replace those. The dealer can do that test or a software program called Auto Ingenuity is available ($350) if you have a laptop. Needless to say it does much more than the test I mentioned. You can also check your local chapter of FTE. Possibly someone near you has it and would be willing to help you out (great bunch of guys on here!)
Hopefully, one of the other items will turn out to be the problem, and your injectors are good.

 

every diesel idles rough when cold and the transmission wont hardly shift but once they warm up everything is good to go

 

I was wondering the same thing about the transmission - if I needed to change the fluid or something. It won't hardly shift when it's cold and I assumed that there was a problem. Now I know that I just need buy a remote start system so that I can fire it up 15 minutes before I head to work.

 

You shouldnt need to let it warm up that long once you find the issue it will shift right

Usually its a FICM issue like Rusty Mentioned

Also check your oil see if it smells like Diesel Fuel and if its making oil

I had my injector orings leak when cold same symptoms as you guys ran ruff wouldnt shift right till warm then it ran great once warm

odds are you dont have any transmission problems and once you fix the rough running condition the tranny will shift right

You could plug it in till you get it figured out that may help