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Thread: A/C Torque Loss ?

  1. #1
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    Default A/C Torque Loss ?

    Will this still work properly when MAFless (G0108 and G0109)? i.e. is it dependent on the MAF input?

    I have a pronounced "clunk" every time the A/C clutch engages at idle ever since I disabled the MAF for AutoVE tuning. Could this be related?
    2017 Camaro SS, 2014 Ram 2500 4x4 Cummins 6.7L, 2004 Chevy Avalanche Z71 4̶X̶4̶(now 2WD), 5870lb race weight, 10.93@ 124, Twin TVS1900s, Twin Throttle, 429 LSX, 4L80E, custom 14 bolt rear, V2, R̶o̶a̶d̶R̶u̶n̶n̶e̶r̶(dead), COS3......
    Gettin' the Groceries

  2. #2
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    Guess I will have to try re-enabling the MAF before going to the dealer for A/C warranty service. Won't look good if it is a result of the tune.
    2017 Camaro SS, 2014 Ram 2500 4x4 Cummins 6.7L, 2004 Chevy Avalanche Z71 4̶X̶4̶(now 2WD), 5870lb race weight, 10.93@ 124, Twin TVS1900s, Twin Throttle, 429 LSX, 4L80E, custom 14 bolt rear, V2, R̶o̶a̶d̶R̶u̶n̶n̶e̶r̶(dead), COS3......
    Gettin' the Groceries

  3. #3
    EFILive Developer Site Admin Blacky's Avatar
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    Check the {B4354} A/C air ramp in, maybe try making it less agressive.

    Also check the amont of air that is being added for {G0108} and {G0109} A/C torque loss. Maybe try making it a little less.

    Also, if there is a large difference between the A/C and non-A/C idle airlfows then you may get a clunk. I get a noticable surge when I engage the A/C at low speed. But I have not tuned my idle and low speed cals since a cam upgrade.

    Regards
    Paul
    Before asking for help, please read this.

  4. #4
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    Quote Originally Posted by Blacky
    Check the {B4354} A/C air ramp in, maybe try making it less agressive.

    Also check the amont of air that is being added for {G0108} and {G0109} A/C torque loss. Maybe try making it a little less.

    Also, if there is a large difference between the A/C and non-A/C idle airlfows then you may get a clunk. I get a noticable surge when I engage the A/C at low speed. But I have not tuned my idle and low speed cals since a cam upgrade.

    Regards
    Paul
    Post seems to have disappeared. I'll try again.

    I tried your suggestions. These tables were all at factory settings to start with. G0108 was all set to 0 and I didn't touch it. Tried decreasing and increasing the values in G0109 in steps with no effect on the "clunk". Same for the ramp-in rate.

    I did notice that Mag had raised idle speed to 600(from 550) RPM. Tried setting that back to 550 also with no effect on the "clunk". Did hear a pronounced knock from bank 2 at 550 RPM though?? Used bidi to try various RPMs. Still no effect.

    I observed that the momentary drop at A/C engagement is about 50 RPM. Whereas, on my Trailblazer with the same engine, it is only 20 RPM. So perhaps it is an A/C system issue.

    Only thing left to try is replacing the 1 bar MAP sensor and the Mag tune before I bring it in to the dealer.
    2017 Camaro SS, 2014 Ram 2500 4x4 Cummins 6.7L, 2004 Chevy Avalanche Z71 4̶X̶4̶(now 2WD), 5870lb race weight, 10.93@ 124, Twin TVS1900s, Twin Throttle, 429 LSX, 4L80E, custom 14 bolt rear, V2, R̶o̶a̶d̶R̶u̶n̶n̶e̶r̶(dead), COS3......
    Gettin' the Groceries

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