Need help w Transission Idle from P to D

[Tfoggy]

I know my tune isn't perfect.. This is my first real tune (for myself).
It's a yukon 6.2 E38 L94 6L80E 2014
Can someone point me to the tables where I'd change/modify my idle when I go from P/N into Gear.
The idle drops quite a bit and stumbles. Sometimes it dies. At operating temps
6.2 L94 Stock bottom, Gwatney VVT1 cam 216/226 113*+8 . Heads cleaned up. Kooks Headers & Cats.

I actually paid for a poor base tune and then decided to finish it off myself, so there's prob stuff that might be
way off.. I have learned a lot for sure. And I really enjoy my transmission now.

This is really the only "true" issue I have right now

[blindsquirrel]

ECM 12135, mostly. You've added a little there but only a tiny amount, start with adding 20 or 25% for the whole table. You can always back it down if it adds too much.

[Tfoggy]

Thank You so much BLINDSQUIRREL I was afraid to add that much I guess. When I did add a bit it didn't really help so
I figured I was on the wrong path... It's turning into a blizzard soon here so I may not be able to test it tomorrow.
I have read lots of your advice to people on this forum, SO THANK YOU for your time and experience

[TheMechanic]

ECM 12135, mostly. You've added a little there but only a tiny amount, start with adding 20 or 25% for the whole table. You can always back it down if it adds too much.

I understand the reason behind ECM 12135 but when and why would you change the BRAF? BRAF first to get a good P/N idle then use the TSA?

[Tfoggy]

I understand the reason behind ECM 12135 but when and why would you change the BRAF? BRAF first to get a good P/N idle then use the TSA?

I've got very good idle in P/N and in Drive/Reverse... It's just when I shift from P into D or R that it needs help.
I've done changes to base running airflow to get my idle at a good point.. In both gear and P/N

[TheMechanic]

I've got very good idle in P/N and in Drive/Reverse... It's just when I shift from P into D or R that it needs help.
I've done changes to base running airflow to get my idle at a good point.. In both gear and P/N

What did you increase your base running airflow by?

[Tfoggy]

So I added about 20% airflow in the transition from P to D/R.. And it didn't help.. Then I added 30% more and it got worse...
So I went back and found the stock #'s from a 6.2L Sierra and put those into the table - was really bad. I did this
just to get back to a known baseline as I've screwed with this a bunch..
Then I added 20% to that "stock" table and it is better than it's been in a while.. Not perfect yet, but close. At
least it doesn't want to die.
I'll post my new update file here.
So you can see my #'s for this and for the Base Running Airflow as well

[Tfoggy]

What did you increase your base running airflow by?

I posted my tune so you can look at the airflow tables... I did my base running airflow tables according to my "tuner school book" about 11 G/S to
start with, then I just kept working on it..
It "used" to be fine the transition from P to D, but somewhere in my tweaking it got crappy. But my idle in P and Gear is fine, just when I shift from P to D it
started acting up.
I really didn't think that this smallest VVT cam would take much, but it has taken a bit (and I'm fairly new to this)

I had it dyno tuned 3 years ago when I put on an Edelbrock E Force SC.. It ran fine, but it was gas pig esp when towing. So I took off the SC
and went with the mildest VVT non DOD cam I could find. And my orig stock gm file was gone ... So I really had to start from Zero

[GMC355]

@Tfoggy, having similar issues with my 2007 L92 Yukon (BTR Truck Norris cam). Idles are great, but sometimes not so much going into or out of gear. Sometimes it's better, sometimes not. Have messed with some of the garage shift settings as well, but going to try to spend some time on it this weekend. Mine seems to be a little heavier load into R versus going into D also, so that doesn't help!

**If you need a latest version stock L92 tune let me know if you might need the OE numbers from that as a baseline to look at.

[morepowerjoe]

I posted my tune so you can look at the airflow tables... I did my base running airflow tables according to my "tuner school book" about 11 G/S to
start with, then I just kept working on it..
It "used" to be fine the transition from P to D, but somewhere in my tweaking it got crappy. But my idle in P and Gear is fine, just when I shift from P to D it
started acting up.
I really didn't think that this smallest VVT cam would take much, but it has taken a bit (and I'm fairly new to this)

I had it dyno tuned 3 years ago when I put on an Edelbrock E Force SC.. It ran fine, but it was gas pig esp when towing. So I took off the SC
and went with the mildest VVT non DOD cam I could find. And my orig stock gm file was gone ... So I really had to start from Zero

I was comparing my tune from GPI I had done a couple years ago with my SS2 VVT camshaft and it looks like to me your proportional airflow is still a little low, don't really know what you started out with but also you have it trying to idle too high in the p/n area of you base setpoint the max I would go is about 725 rpm. As far as the rest of it the ect mult 12198 is about 3 times to high. I would start by reducing it as much as 50% and then raise up your p/n transition 12136 about 50%. And then your torque 12123 in between 6-800 rpm is around 50% too high, and lastly your airflow max 12128 should be between 70-80, oh and by the way you your maf calibration is way off I believe but I'll have to let someone with more knowledge then me to help you with that. I know you'll have to data log it and then copy and past a few times to get the maf dialed in and it's a process. I would maybe try one thing at a time to see what happens but some parameters might not play out to well without each other. Hope this helps and like I said this is my knowledge of a GPI tune.

[Tfoggy]

I was comparing my tune from GPI I had done a couple years ago with my SS2 VVT camshaft and it looks like to me your proportional airflow is still a little low, don't really know what you started out with but also you have it trying to idle too high in the p/n area of you base setpoint the max I would go is about 725 rpm. As far as the rest of it the ect mult 12198 is about 3 times to high. I would start by reducing it as much as 50% and then raise up your p/n transition 12136 about 50%. And then your torque 12123 in between 6-800 rpm is around 50% too high, and lastly your airflow max 12128 should be between 70-80, oh and by the way you your maf calibration is way off I believe but I'll have to let someone with more knowledge then me to help you with that. I know you'll have to data log it and then copy and past a few times to get the maf dialed in and it's a process. I would maybe try one thing at a time to see what happens but some parameters might not play out to well without each other. Hope this helps and like I said this is my knowledge of a GPI tune.

I'll give this a shot. Thank you for the advice. Like I said, I'm still learning and have had to start from scratch as the first tune was from my Supercharged version.. Then I went somewhere
else to do the cam only version (no supercharger) and instead of just starting with a stock file... I believe they tried to just make changes to the supercharged tune... which I didn't want...
So I'm working on it !!! Thanks for the help !!! I'll report back with just these changes

[rickylee]

Wanna sell the supercharger? I have the stage 2 vvt cam from GPI. I cant get the idle right either. It?ll be good one day and not so good the next. Following for insights.

[reubone]

MyYukon12202022addedtransidleairtry.hpt
Try that, I only made a few changes that have to specifically address the issue , the rest of the file is untouched. If the idle is too high, reduce the effective area min. If it still stumbles increase it a bit

[Tfoggy]

I did follow the advice here given.. I've got the P-D transition behaving correctly now..
It just took some experimentation to eventually get it right.. Thanks to everyone for all the help.
Had a new granddaughter 10 days ago so I was out of town and didn't get to reply