Tune issue on Duramax LMM truck

[bondurch]

My tune issue is this. Currently I run two different tunes that work absolutely perfect. A third tune that I attempt to run “a race tune” will not let my truck run properly. I believe it goes into limp mode either right at start up or when I have been driving for 3-5 minutes. The truck just starts sputtering, blows a bit of white smoke and has absolutely no go power. I may get 5 mph out of her when she is acting up.

Does this sound like limp mode and is there anyone who would like to take a look at the tune to help me diagnose the problem. I need more qualified eyes.

[killerbee]

beekiller at cox net

no guarantees, what are the codes

[tblu92]

Does the race tune delete the EGR valve ? I have had to re-anble the EGR on some LMM tunes as it would make it smoke white smoke and sputter badly with it tuned off-
ALSO--have you taken the DPF off the truck ?? If not the DPF filter will plug up with any tune that adds too much fuel--many handheld programmers or banks tuners have what they call a "clean tune" these tunes only add timing and no fuel but are limited to around 50-75 HP

[bondurch]

Does the race tune delete the EGR valve ? I have had to re-anble the EGR on some LMM tunes as it would make it smoke white smoke and sputter badly with it tuned off-
ALSO--have you taken the DPF off the truck ?? If not the DPF filter will plug up with any tune that adds too much fuel--many handheld programmers or banks tuners have what they call a "clean tune" these tunes only add timing and no fuel but are limited to around 50-75 HP

Thank you tblu92 you nailed it pointing out the EGR as the issue. I ended up tweaking the duty cycle and temp params, and it worked. In fact the truck works really well. The tune is spectacular. Thanks to IdahoRob for hooking me up with the power. I guess I should read up on the egr removal.

[tblu92]

Glad it worked out for you-----When the LMM's 1st came out I had the 1st 4 tunes come back with white smoke--no power--sputtering--I tried like heck to figure it out and at the time beacuse they were so new--no one really knew much about how to tune them properly and work around the DPF filter-
The biggest problem was not having a LMM of my own to work with--So I finally called one of the LMM guys that had the issue and offered him $100 to borrow his truck for a day and use it as a ginney (?) pig--and promised to return it back to stock when done---I strarted by changing one table at a time -starting with the most important stuff 1st--and worked my way down--When I got to the EGR parameters it started to smoke/sputter---Yea !!! so from then on i just leave them be on the LMM's--- ( my favorite Duramax is the LBZ ) responds well to tuning--no problems--no codes--shifts well--learns fast--some guys around here in 2007-8 were ordering NEW trucks and paying extra for the LBZ rather than the LMM---

[bondurch]

Hmmm that sounds like the issue I am having. White smoke a sputter with no power. I will look into the EGR parameters and see if that solves my problem. This tune drops a bunch of fuel and I do not have any issues with filters plugging.

[The Neens]

I've also had similar LMM issues with the EGR...Also, I would only contact IdahoRob regarding his tunes...I'm sure he can help you out...

[bondurch]

I did contact IdahoRob regarding the tune. He has looked at it numerous times and can not find any issues. He says it runs great on a number of LMM trucks. I do want to say that Rob is great to work with! He set me up on another tun that did work really well.

The tune I am having issues with has been bugging me for a while, and that is why I have opened the issue up to a wider audience. When I get to run the truck on the tune (for a couple of minutes) it really runs nice. Thanks for the advice on the EGR issue. I will see if I can figure out what to turn on or off. My first guess is that I need to change the EGR duty cycle parameters?

[killerbee]

It could be anything at this point, let's look at a log. That should handily answer your question. It may well not be tune related, though I see why you would come to that conclusion.

[The Neens]

I would do a comparison of the "bad" tune to the 2 good tunes...See what the differences are, then change 1 table at a time until you find the culprit...Process of elimination...