02 LB7 Trans De Fueling

[RMJ_LB7]

I have been having fun writing a couple of tunes and think I have gotten to a decent street/DD tune. However the truck is wanting to Defuel really badly and was reading about it all night last night and from what I could gather everybody is saying fix the de fuel through the ECM and not the TCM? Not wanting to completely remove the defuel, just want it to shift without taking 2 seconds. Any help would be appreciated.

 

[2004LB7]

Did you ever get a chance to try my defuel calculator out?

https://www.duramaxdiesels.com/forum/showthread.php?t=15659&page=3

 

[RMJ_LB7]

Did you ever get a chance to try my defuel calculator out?

https://www.duramaxdiesels.com/forum/showthread.php?t=15659&page=3

I will try it tonight :thumb:

 

[2004LB7]

Let us know. I'm curious to see if my math works out

 

[RMJ_LB7]

Let us know. I'm curious to see if my math works out

PM me so I can get your email, I think there is a few things that need to be fixed.

 

[2004LB7]

Is there any reason not to post the information in the forums for everyone to learn? What kinda things are you thinking needs changing?

 

[RMJ_LB7]

So when messing with the calculator, I left 0-600 RPM alone like you suggested. I got 0-80 % throttle pretty dang close to 0 with +/- 2. I went and tested it and it shifted very well! I was scared to do 80-100% close to zero but I am going to get it to around -10? or do you think that would be not enough defuel at 100% throttle? its at -21 right now below 2200 RPM and around -13 from 2400-3800RPM.

The calculator itself seems to work very well though! :thumb:

 

[Chevy1925]

If it shifts smooth as butter in the 80-100 range, I’d leave it. If it’s hard, back it down

 

[Mike L.]

Factory defuel is perfect.

 

[2004LB7]

Have you tried the newest calculator? That one is all automatic. Post #117 I think of that thread I linked above

In my logs, when the (old) calculator was set to "zero" it still defueled. The numbers I think are what the ECM calculates its defuel off of. Example: the transmission is currently receiving 500 lb/ft and wants to shift, it asks the ecm to defuel 20%, the ecm looks at its torque tables to see what the fuel amount for 20% less torque. If the fuel is too high as it normally is when making tunes, instead of dropping the fuel it may actually go up. By matching what the commanded fuel to the torque and defuel tables then when it asks for 20% less it gets 20% less.

My logs showed that the numbers in the defuel table was not the actual amount injected but where the ecm started from when subtracting the requested amount

 

[Chevy1925]

So when messing with the calculator, I left 0-600 RPM alone like you suggested. I got 0-80 % throttle pretty dang close to 0 with +/- 2. I went and tested it and it shifted very well! I was scared to do 80-100% close to zero but I am going to get it to around -10? or do you think that would be not enough defuel at 100% throttle? its at -21 right now below 2200 RPM and around -13 from 2400-3800RPM.

The calculator itself seems to work very well though! :thumb:

i would also make sure you give this time. drive it for a week and pay attention to how the truck acts under all driving conditions and trans temps. you have to see if it ever learns out of what you have input in.

 

[RMJ_LB7]

Have you tried the newest calculator? That one is all automatic. Post #117 I think of that thread I linked above

I am going to try the automatic one now and see how well it works!

i would also make sure you give this time. drive it for a week and pay attention to how the truck acts under all driving conditions and trans temps. you have to see if it ever learns out of what you have input in.

I am going to fix the 80-100% and see how it reacts and then drive it for a week and make sure everything is good. At the 80-100% its not smooth it definitely defuels.

 

[RMJ_LB7]

2004LB7, I am getting an ERROR halfway through B0741 table. Any help?

 

[2004LB7]

right off I can see that Open Office is altering the santex a little. I wonder if this is the reason for the error.

PS: sent you a PM

 

[RMJ_LB7]

The Calculator that you do manually worked fantastic for me on the Open Office, it took a little time to get it dialed in but just went for a test run and seemed to shift great. Going to give it a week and see how it does.

 

[2004LB7]

Email sent

 

[2004LB7]

https://1drv.ms/x/s!AuWzAKOIb4Q3bo7DKI9vf47mDnM?e=PvUDic

see if this link works for you to open the document online

 

[2004LB7]

any updates?

 

[RMJ_LB7]

any updates?

Haven't been able to test the automatic one yet... However drove the truck all week and the manual calculator worked awesome and still shifts great! I just got my DSP5 switch in and gauges will be here friday so I can monitor better and write a couple more tunes :woott:

 

[2004LB7]

Try out the link above, post #17, for the online version and see if that works