I wonder if he ever got this resolved?
Dfe1 and I are going to do some testing next week. We will try to duplicate the problem, and then try Tow/haul, then reflash to stock tune, and see what happens....Originally Posted by lakingslayer
for the help....
One of the best things that you can do is to get away from the 2001 OS and run the 2002 ECM OS as there are just some odd things with the 2001 programming.
www.kennedydiesel.com
Specializing in Duramax Performance
More than just a salesman-I use and test the products that I sell on a daily basis.
Superflow Lie Detector in house
Attached are two data logs of Chuck L's Duramax, one with a stock tune, the other with a modified +/-100 hp tune. We never experienced the shifting problem, but as you can see, the rpm graph in modified form doesn't look right. Any ideas? We also had a G-Timer runing and it consistently showed a 2 second (two, not two tenths) improvement in 0-50 times.
Last edited by dfe1; April 12th, 2006 at 03:03 AM.
DigitalEFI- EFILive US Distributor
sales@digitalefi.com
678/344-1590
Looks like you were at 3250 and could have been bouncing off the rev limiter, also at WOT 100% in Non-TH the Converter will be slipping and not locked.
The drops in the fueling mm3 coincide with the rpm changes, those are TQ Limited injection Quantity commanded defuel on the shifts.
Dave, is that second tune the one I sent over to you in December ??? Or is it one you wrote.
TONY
BTW, if you have a commercial version you can reflash your 2001 ECM O.S. to a 2002 O.S.
I just did one and it works fine on ECM Hardware #9355100 -Original O.S. #15188873 Calibration #15063375
to a 2002 ECM O.S. #15186006 Calibration #15166858.
Tony-Originally Posted by GMC-2002-Dmax
It is the second tune you sent back in December. Seemed to work fine for a few months, then recently started acting up. I pulled back on the fuel about 10% and that seems to have fixed it, but until we have a few miles on it, I don't want to say for sure. Power appears to be down slightly, but that's to be expected with less fuel. I don't think we're tapping the rev limiter-- I moved it to 3650, but even if you hold the trans in gear, the engine won't go over 3400-- I think that's the result of a fueling calibration. What are the advantages of the 2002 O.S.? I do have the commercial version.
DigitalEFI- EFILive US Distributor
sales@digitalefi.com
678/344-1590
Dave,
The 2001 O.S. is unique and a one year only O.S.
It has been known to do very strange things with regards to handheld Flash Tuners corrupting the data.
EFI-LIVE seems to be the only software working without issue, but there have been issues with the 2001's getting weird for no reason.
We found out years ago that the 2002 ECM's always worked very well in 2001 trucks, Nobody until now had a way to update the 2001 ECM's to 2002 programming, calibrations.
I just did a BENCH FLASH Full O.S. update on a 2001 ECM to a 2002 O.S/Calibration and tested it in my truck.
All worked well and it seems that a lot of 2001 specific problems can be traced to the ECM and programming.
Tony
Last edited by GMC-2002-Dmax; March 6th, 2006 at 05:23 PM.
Tony-
Right now the truck seems to be running fine, but this stuff is pretty spooky in terms of the way the trans reacts to changes made to the engine calibrations. As I mentioned, the tune that you sent worked great for a couple of months, then the trans started acting like it was infested with gremlins. The same thing may happen with this tune, we'll have to wait and see. I'll try upgrading to a 2002 OS in a few weeks and see what the effects are. I'm assuming the upgrade works just like it does with the gas engines-- you just do a full reflash, then load in your calibration file and save everything. Thanks for all your help and input.
Dave
DigitalEFI- EFILive US Distributor
sales@digitalefi.com
678/344-1590