Well I guess the Tunner was not the fix, when I drive the truck when it is cold it is still sputering/bucking at that O/D low RPM's I think I am going to try the HSS product I have read about. I have a diagnositics on the Bully Dog GT I ran that while the truck is bucking, but no DTC show up so I am not sure why there would be no fault codes? Has anyone else came up with a solution yet?

 

My truck does this once I got my SCT X3 with a local guy's custom tunes. He said that in my case, what it is is that the high hp tunes make your truck drive normally for the first half of the throttle position, but then for the other half (its actually not divided directly in half but for the sake of explanation that's what I called it) is for the "extreme" driving...like racing. However, there is a certain throttle position where you're "on the fence" and it doesn't know if you're wanting to stay normal or go extreme, so the truck is all over the place with boost. He said that if you watch your boost gauge you can see it going all over the place. The only problem is I can't confirm this because every time it happens I just try and stop it and don't think to look at my gauge. He told me that he can fine tune it so that it won't do it anymore, but it would take a lot of trial and error and a few hours of driving it, then slightly changing some stuff, then driving some more, then slightly changing some more stuff. I'll probably let him do it one day when I got nothin else to do. My problem right now is, and I'm hopin it's because I haven't had it retuned since my EGR delete, but my truck will start bucking at WOT when it hits around 65-70mph and it makes a loud "spitting" sound and won't really go any faster unless I back off the throttle. Hope it isn't glow plugs or injectors...

 

I watch my boost on my BD dispaly and it dose not jump and only does it when cold I would think if that was the case it would do it all the time

 

I still think you should check the injectors.

co-workers 6.0 had weird problems like yours when it was cold. was his injectors.... for the 3rd time

 

Mine is doing the exact same thing. Once it hits OD it miss's slighty. Try flooring it to see if you notice any changes. I got pissed with mine and stuck it to the floor and noticed under hard acceleration it will surge somewhat. At 50-80 holding it down I notice alot of back and forth power gains and loss. I also have a new FICM. Swamps 58volt with hot flash. My wrench comes on sometimes while driving for a long way. I stopped at Autozone the other day, scanned it and had two codes. One EGR emissions and the other Modification code (don't have the actual codes).

Just changed fuel filters, oil filter, T6 Synthetic oil, changed places I was buying diesel. I noticed this problem with mine after my water in fuel light kept coming on everyday. I would drain it and there be nothing in the fuel. I did have some bad diesel at one point i found dirt and some water but after two fuel filter changes everything cleared up no more lights on either. BUT thats when i started having this problem.

 

Improper procedure for clearing / resetting computer.

Proper procedure is to remove both battery terminals.

Then turn on the headlight and dimmer to high

Then wait 30 min for the capacitors to discharge.

You know the reset worked well if the transmission shifts roughly until it relearns.

 

I have the exact same problem with my 03 Expedition which I have owned since new. My Expedition is completely stock, well maintained, and no custom tuning. I brought it to the dealer several times but they can't duplicate the problem. I assumed the transmission was going, but it sounds like it may be something else from this thread. At one point I had a problem with it stalling out on the highway, and after a week the dealer said it was intermittent low fuel pressure and they replaced the fuel pump. The overdrive sputtering still happens with the new fuel pump. If you find the problem on yours, please let me know.