Results 1 to 6 of 6

Thread: G8 idle issues

  1. #1
    Tuner in Training
    Join Date
    Nov 2016
    Posts
    33

    G8 idle issues

    im working through a new tune using my newly acquired GM basic user course from the tuning school. im on the 8th step right now, had a good idle setup and started to dial in the MAF yesterday. this morning i started the car up this morning and it hesitated slightly when i put the car into reverse and did it again a few other times driving the rest of the work. When it happens i can put the car into neutral and and steadies out. i had no problems with getting the tune squared away until this morning. i do have a small oil leak and i have basically no brake pedal. the pedal goes all the way to the floor and the car slowly comes to a stop. ill paste the tune and the log from the ride in this morning. let me know what you think.
    oh, the car is procharged with a lunati vodoo blower cam and 65lb/hr fast injectors
    STEP 8 1.hplJoe Lewis 2009 G8 GT STEP 8.hpt

  2. #2
    Tuner in Training
    Join Date
    Nov 2016
    Posts
    33
    Could this be caused by torque management? That was the only thing I changed between when the car was driving fine and than having these problems.

  3. #3
    Tuning Addict 5FDP's Avatar
    Join Date
    May 2012
    Location
    Rogers, MN
    Posts
    13,533
    You could log all your spark correction channels to see what spark is doing.

    I do highly suggest you cut the under/overspeed spark correction tables by about half, this way the computer can't swing the timing anywhere from +14 degrees to -13 degrees. That is a large amount of movement that is allowed and with the camshaft way less would be wanted. It should keep idle smoother while things get dialed in.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  4. #4
    Advanced Tuner
    Join Date
    Feb 2015
    Location
    Perth, Australia
    Posts
    974
    disable garage shift torque management.
    max and disable fast torque exit
    turn off injector desoot switch

    sort out your spark correction area, like piston slap, cat heating etc.

    populate the main spark tables and coastdown idle tables with some bigger numbers in the .40 and up cells 600 rpm and below

  5. #5
    Tuner in Training
    Join Date
    Nov 2016
    Posts
    33
    i still need to adjust the timing tables as suggested but ive edited the airflowJoe Lewis 2009 G8 GT STEP 8 (REV1) adjusted idle airflow tables rev 1.hpt

  6. #6
    you may be able to add air flow to the cells that are having a hard time keeping up/ mine would stall under load ,like drive or ac, and wouldnt return to idle after a quick blip on the throttle, so I just added some air.