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Thread: Desired idle goes up on it's own p59 3bar OS

  1. #1

    Desired idle goes up on it's own p59 3bar OS

    I have seen this once before and didn't have an answer.
    Desired idle doesn't match the table.
    On start up 150rpm is added.
    Over next 20 seconds it goes to desired idle.
    Then at 55 seconds another 150rpm is added over next 15 seconds.

    What adds to desired idle RPM?

    Tune and log attached.

    idle.hpl
    005_STR.hpt

  2. #2
    Senior Tuner
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    Very likely has a vacuum leak. If you try to control the Idle rpm with your scanner, does it follow the commanded idle speed?

  3. #3
    Actual idle follows Desired Idle RPM. I have full control over the idle with the Scanner Controls.

    The Desired Idle RPM table is set to 700.
    The car starts - I can watch Desired Idle RPM in the scanner go to 700 (so does the actual idle).
    50 seconds after starting "something" raises the Desired Idle RPM to 850 (so does the actual idle).
    I can't figure what that "something" is.

    It seems no matter what I set Desired Idle RPM table to - 150rpm is added.

  4. #4
    Anyone?

  5. #5
    Senior Tuner Ben Charles's Avatar
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    I’ve seen this before 2x... ended up doing a write entire with another OS and fixed it

    Email Tunes, [email protected]
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  6. #6
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    Quote Originally Posted by Ben Charles View Post
    I’ve seen this before 2x... ended up doing a write entire with another OS and fixed it
    I'm clicking the Like button.

  7. #7
    Quote Originally Posted by Ben Charles View Post
    I’ve seen this before 2x... ended up doing a write entire with another OS and fixed it
    this

  8. #8
    Senior Tuner Ben Charles's Avatar
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    I’m wanting to say it was Truck OS both times and literally happen around the 45 second to minute mark

    Email Tunes, [email protected]
    96 TA Blown/Stroked, 4L80E/Fab 9
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  9. #9
    Just ran into another one doing the same.
    02 Silverado, 1 BAR OS - idle runs off.

    Switched to Camaro OS. Fixed!

    Thanks Ben!!!

  10. #10
    Working on 06 Silverado. Idle runs off for no reason in both original and SD OS's. DBW F-body OS is not an option
    Going to try to flash everything back to stock with GM SDS.

    Why is this a thing?

  11. #11
    Tuner in Training
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    I have an 04 Tahoe P59 OS with 3 bar upgrade and mine is doing the same thing. Desired idle going up 100 rpms and I can't figure out why.

  12. #12
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    Tables we cannot see possibly?

  13. #13
    Senior Tuner Ben Charles's Avatar
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    Quote Originally Posted by reubone View Post
    Tables we cannot see possibly?
    That would be my guess… but something that can normally be modded I believe is trigging it… not 100% sure what???
    Always just change OS and works fine

    Email Tunes, [email protected]
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  14. #14
    Quote Originally Posted by Ben Charles View Post
    That would be my guess… but something that can normally be modded I believe is trigging it… not 100% sure what???
    Always just change OS and works fine
    when you do this, do you have to buy credits again?

  15. #15
    Senior Tuner Ben Charles's Avatar
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    Quote Originally Posted by tana99ss View Post
    when you do this, do you have to buy credits again?
    Yes…

    Email Tunes, [email protected]
    96 TA Blown/Stroked, 4L80E/Fab 9
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    Custom Mid Engine chassis, AKA GalBen C

  16. #16
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    Quote Originally Posted by Ben Charles View Post
    That would be my guess… but something that can normally be modded I believe is trigging it… not 100% sure what???
    Always just change OS and works fine

    Wouldn't happen to have a stock tune OS that's fixed it in the past? I don't want to pay for credits if I chose an OS that doesn't work.

  17. #17
    Senior Tuner Ben Charles's Avatar
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    I don’t recall which OS it is, but it’s a truck OS ‘em that does it, Fbody never had a problem

    Email Tunes, [email protected]
    96 TA Blown/Stroked, 4L80E/Fab 9
    15 C7 A8 H/C 2.3 Blower/PI
    14 Gen 5 Viper
    Custom Mid Engine chassis, AKA GalBen C

  18. #18
    Tuner in Training
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    Appreciate the info!

  19. #19
    Tuner in Training
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    @moboost, any solution to this? I am having exact same issue.