Hey all, I am hoping to find a solution here. I have a 2007.5 6.7 all stock with about 78,000 miles. On cold mornings, Say below 40, I start up the truck and let it warm up for about three minutes through the grid cycles, then when I drive to the first stop sign by my house about 50 yards away and come to a stop, the engine surges for about 2 or three seconds and wants to pull me out into the intersection. I have to press on the brake harder until it clears up. It does it once or twice until its a littlle warmed up and then its fine! There are no lights or codes and like I said, it only happens no cold mornings. What is going on?

 

This is normal... When you come to the stop, it is still going through its cycles.

 

This is a strong surge. Enough to make the truck lurch forward at idle. It only started happening last year. This is after the complete three minute grid cycle.

 

When stopped, it will still do the cycling if the air is cold enough and such. I bet you could see the voltage dropping (and or lights dimming) when this happens too.

 

my recommendation first of is to engage your exhaust brake and turn your high idle on on cold mornings and let it run for 5-10 min before hoping in and taking off that way all your fluids are some where close to normal temp and truck heater is warm too but the surge is most likely coming from the torque converter locking up with the dip in idle then the rev up

 

I just recently had to do the EGR cleaning at app. 57k on my '08. I don't know if its just coincidence but my truck's cold surges much less now, after the cleaning, than it did prior to.

 

I had mine cleaned at the suggested interval, then I just had to get the EGR valve replaced about two months ago (figures). I don't think it helped mine much. I also heard it may be dirty battery terminals of all things. I cleaned them up but it still did it. Maybe I will let it warm up longer than 3 minutes and see of that helps. If not, I will park it at the dealer a couple days. I would hope the whatever is causing the problem is still under warranty. Torque converters aren't cheap.

 

davifam -
It appears this topic has "gone cold"... pardon the pun. Just curious if you got to the bottom of this or are just living with it?

I'm not a diesel mechanic expert and you probably already know Cummins uses the heater grid in the intake and will cycle for several mins until the computer senses the incoming air is warm enough. Cycling of the alternator is normal, but the engine surging to the point it lurches the truck forward is not. I believe this issue is tied into the electronics side of the fuel injection system.

I don't know if that means it's at the injectors or the injection pump; my guess is it would be the pump. To some degree, my truck has always had a "stumble" of some sort after start up on those really cold days and when the engine has been cold-soaked for awhile. I've brought this up to the lead diesel mechanic (a friend) at the dealership here; he hasn't heard of my symptom before.

Sooo, I'm just saying that I think, quite possibly, you and I both have some sort of electrical interruption going on in the fuel injection system caused by the cycling alternator. I've just learned to live with mine, but I'd want to get to the bottom of it if my truck was lurching into an intersection unexpectedly when it was going thru the cycling period.

 

I get a surging while accelerating in cold weather. At part throttle I get a rum, rum, rum,....