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Thread: 2017 GMC Sierra 6.2l Cam Tune

  1. #1
    Tuner in Training
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    2017 GMC Sierra 6.2l Cam Tune

    Had a cam install done and the shop gave me my truck back stalling and refusing to start at times. I got it to stay running and not stalling by editing the idle tables. I am including the original tune file pulled when i got it back from the shop and the new one I am running now with my idle changes.

    I think the VVE tables are messed up because it is still running rough and has hesitation on accel.

    cam specs:

    25-TSPL83TR-2-32 - Texas Speed & Performance Gen
    5 L83 5.3L Stage 2 Camshaft w/ +32% Fuel Lobe:
    218/226, .635"/.635", 113 LSA, 109 ICL

    please let me know if you see any glaring issues.

    also included an idle log.

    2017GMCSierra62-fromshop.hpt
    2017GMCSierra62-mychanges.hpt
    rollingidle01.hpl

  2. #2
    Advanced Tuner
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    I'm just learning too but i have the same cam and same engine in my 2014 sierra. I can't pull it up at work but I'll try and take a look at it later.

    You can take a look at my tune on this page. WOT throttle tuning was done here but the truck was running good with no hesitation or anything like your going through.

    https://forum.hptuners.com/showthrea...about-PE/page2

  3. #3
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    Quote Originally Posted by Jonblarc7 View Post
    I'm just learning too but i have the same cam and same engine in my 2014 sierra. I can't pull it up at work but I'll try and take a look at it later.

    You can take a look at my tune on this page. WOT throttle tuning was done here but the truck was running good with no hesitation or anything like your going through.

    https://forum.hptuners.com/showthrea...about-PE/page2
    Just making notes on some differences

    -idle speed reserve table is pretty close to stock on your truck. I've heard two different places that lowering it by 20% when you install a bigger cam is the way to go. due to the cam being inefficient down @ idle and needing less air. I know it helped my truck from not starting and stalling. tuner at shop did the opposite and raised them by 20-30%. Pretty sure it also helped because my MAF/VVE needs to be tuned properly.

    -how I edited my idle torque limit/external load table was by inputting the value of 50 at target RPM and extrapolate up and down.

    -one of the biggest reasons my truck was stalling was the rolling idle tables were untouched from stock it was allowing a dip to 585rpm@0mph.

    -What is a good target RPM for this cam? I see you chose 735. I was aiming for 700 but I think a little higher were you are at is better.
    Last edited by Wildlyfe200; 04-15-2021 at 11:29 AM.

  4. #4
    Advanced Tuner
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    I've had the idle rpm all over the place for 680 to 820 and found higher is better. I had it down at 735 trying to get it to chop more. But I ended up play with the under over speed tables to get it to chop pretty good. Right now I have the idle base set point at 780 and really like it there.

    And my rolling speed Rpms are 820 in the first couple colums in first and reverse.

  5. #5
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    Quote Originally Posted by Jonblarc7 View Post
    I've had the idle rpm all over the place for 680 to 820 and found higher is better. I had it down at 735 trying to get it to chop more. But I ended up play with the under over speed tables to get it to chop pretty good. Right now I have the idle base set point at 780 and really like it there.

    And my rolling speed Rpms are 820 in the first couple colums in first and reverse.
    I am making sure i don't go below 700 for now. Defiantly interested in some more chop but for now tryin to get a decent MAF tune. I am vey lean at idle and all over.

    This is in forced closed loop.


    Screenshot (60).png
    Last edited by Wildlyfe200; 04-15-2021 at 07:14 PM.

  6. #6
    Advanced Tuner
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    Use your STFT with your O2's or STFT+LTFT to tune your idle and just cruzing around fuel trims. I saw you other post about wideband. When i started tune this truck I used the Wideband to do the part throttle tuning and it would never line out each time I made a change.

    It wasn't until I did all of my tuning out of PE using the O2 sensors. Then I did some short WOT only logins using the wideband. Then all my fuel trims started to fall in place.


    Send me a PM with your email and I'll show you what I did for some more chop.