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Thread: LS6 CTS-V Idle Dropping/Stall when coming to a stop

  1. #1
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    LS6 CTS-V Idle Dropping/Stall when coming to a stop

    Here is the tune file, tuned by Kesatie Motorsports back in 2014. This is a 2005 LS6 CTS-V with a 228/228 with 114+2 LSA custom ground cam, ported LS6 throttle body, and Kooks longtube headers. The car doesn't currently have a wideband. The setup made 403/369 when tuned.

    The issue I am having is that when the car is coming to a stop and I throw the car in neutral, the car will drop idle to around 500rpm, surge, and then catch itself and even back out when stopped. Additionally when I am coming around a curve near my house, with the car in third and keeping the clutch in until the corner exit, the car will drop the RPM and stall out. Should I be looking at the base airflow table or the throttle cracker/follower settings? Not new to HP tuners but the Gen 3 platform is a first for me. I appreciate any and all input/direction! The car drives great otherwise and pulls nice and hard.

    Tune file: El Choppo as found.hpt

  2. #2
    Tuning Addict blindsquirrel's Avatar
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    Lazy-assed 'MAF-only' tune, with the VE unchanged from stock. Fantastic. It needs to be tuned properly to fix your issues.
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  3. #3
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    I'd tune it first in SD. You can re-enable the maf later but it will likely drive better anyway.

    When it is tuned in SD I'll bet the problem will resolve. If not base airflow table can be looked. Use the idle trims LTIT and STIT to dial this in.
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  4. #4
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    Would you recommend adjusting the High RPM disable once SD tuning is complete as well? I noticed that VE is basically disabled since it is "off" above 1k RPM

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    Start from scratch or use this as a baseline to retune?

  6. #6
    Senior Tuner edcmat-l1's Avatar
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    If the VE table is untouched, you're basically starting from scratch anyway.

    You might want to pull a tune file off the repository and use it for comparison.

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  7. #7
    Advanced Tuner abc's Avatar
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    Is this a new problem or something you have been dealing with since the original tune?
    Idle spark looks excessive also, no torque reserve.

  8. #8
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    I just bought the car a few weeks ago so I am unsure if that is how it has always been. I did notice the idle spark seemed extremely high.

  9. #9
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    Quote Originally Posted by Randymc5 View Post
    Start from scratch or use this as a baseline to retune?
    I'd start over if it was me.. Don't want to be chasing something down that is the result of someone changing stuff they shouldn't have.
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  10. #10
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    10-4 I’ll start on that this weekend. I also noticed that the stalling issue only happens when cold. But the idle always drops when coming to a stop. Not sure if that changes anything. Maybe something to do with the ECT/Idle table

  11. #11
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    Quote Originally Posted by Randymc5 View Post
    10-4 I’ll start on that this weekend. I also noticed that the stalling issue only happens when cold. But the idle always drops when coming to a stop. Not sure if that changes anything. Maybe something to do with the ECT/Idle table
    Get your VE table recalibrated and then address idle issues. If you do it the other way around youll just be chasing your tail. Id reset any modifier tables back to stock until after VE and MAF are recalibrated, then make whatever changes you want to suite your liking.
    Heres a link for a good gen 3 idle tuning write up https://forum.hptuners.com/showthrea...e-(w-pictures)
    "I don't care how it runs as long as it chop chops at idle"

  12. #12
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    i'm searching for my own fix for a similar issue on my 04 vette... I noticed your throttle cracker table is completely zeroed out. That can't be helping the problem...

  13. #13
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    Quote Originally Posted by 04Vette View Post
    i'm searching for my own fix for a similar issue on my 04 vette... I noticed your throttle cracker table is completely zeroed out. That can't be helping the problem...
    Do you have similarly poor VE tuning?