I have a 08 6.7 diesel. When I bought the truck at about 1000 miles I started to feel a buck or jerking when letting the gas pedal off and then lightly accelerating. I also seems I have a dead pedal from my take off. The dealership has thrown numberous parts at the truck and still has not been able to fix the issue. I will be going in for the 10th time to have them try and fix the problem. My buddy and I thought turbo but this was replaced last time and still has not made a difference. They also replaced the torque converter and this did nothing. Does anybody have any idea as to what is happening with the truck?

 

I had a similar problem with my 01. Everyone thought transmission shifting sensors etc. It turned out to be my lift pump was going. It may have been a clogged screen but I replaced the pump and all the jerking went away. It was starving the injector pump. The damage was done. It lasted about a year after that. It's worth looking in to.

 

I will have the mechanics check this when I take the truck in tomorrow. The mechanic did find two injectors were starting to fail and replaced them. Would the pump problem start to weaken the injectors? I really appreciate the feedback and will keep you posted when I get the truck back. If anyone else has had similar problems please post. Thanks

 

Don't think the lift pump will affect the injectors. It supplies fuel to the injector pump which in turn delivers high pressure fuel to the injectors. If is was starving the injector pump that much you would have seen a lot of white smoke.

 

I'm so glad I finally ran across your post. I own an '07 2500 that's doing the exact same thing...only regardless of speed. Been trying to get my local Dodge dealership diesel mechanic to repair this for over a year but because no tc is set all he can do is blame it on a dirty turbo. Have you replaced your lift pump yet? If so, did it fix your problem?

Don

 

*UPDATE* My "bucking" issue has been resolved! After taking my truck on a lengthy test drive, a local diesel mechanic diagnosed my problem to be electronic/computer related and suggested I have Dodge "flash" my TCM (transmission control module). He was thinking the tcm was having trouble relearning shift points, etc. having uninstalled my Edge box several months prior. This is a "dealer only" task so I took the truck to a local dealership and had it done...something I guess they'll do anytime per customer request. Anyway, my "bucking" problem has completely disappeared. It's like a new truck again! I have my power back and there are no dead spots in the throttle. Why the dealership couldn't diagnose this is beyond me but it has destroyed my faith in their ability to properly diagnose and repair problems. Not only that, the engine portion of my warranty has been restricted because I had them trying to diagnose this problem with the Edge box mounted...not installed and connected...just mounted. Some service writers are just plain jerks (being very nice with that word). My hats off to G&R Diesel in Draper, UT. They'll be getting all of my future business.

 

I have this same exactly problem as well as when towing my 5th wheel I have no power. Its been in 5+ times and they have updated the computer etc but still nothing. I will tell them about the TCM, but wonder if thats the same thing they've already done (or do they normally do the ECU)?

If feels like the freaking tranny is going to drop out. This thing used to be able to pull my 5th wheel like it wasnt even there...now I get passed by gassers on mid-grades.

 

8 visits later and still no fix for mine. Several dealers refuse to reset the TCM, saying it will do nothing. I am hoping to find one locally that will do it.