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Thread: E38 - How to smooth out Idle/Low RPM - MAF only?

  1. #1
    Member tunedportcj5's Avatar
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    Default E38 - How to smooth out Idle/Low RPM - MAF only?

    Forgive me if I have missed this in another post or tutorial, i have been researching for the past few hours with no luck! ;-)

    MAF tuning has been a dream with the E38 but smoothing out idle - and low rpm accell has been a bit more challenging. If I fail the MAF to SD, my idle/accell issues go away. MAF BEN's are +/- 2%.

    Motor is a stock 4.8, LS3 MAF, LS2 intake, with LS6 cam. 80lb injectors could cause an issue I guess.

    Can I run SD until a certain RPM or MAF frequency? I set my MAF fail LOW to 3000hz, it failed but would not re-enable above those frequency's and stuck with the VE values. I thought it is supposed to re-enable?

    edit1_0008.tun

    Thanks,
    David
    '94 Lexus SC300 LY2 4.8, LS6 cam/springs, E38, LS3 MAF, LS2 intake, 88mm TB, 2bar MAP, T42/4L80e, mpt70
    www.terratraction.com/gallery

  2. #2
    Lifetime Member swingtan's Avatar
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    A log of the issue would help. With the mods you have, I would expect the car to run like a stocker, especially with the auto. In most cases I've seen, low speed roughness is usually due to fueling, so I'd start there. The logs will tell the story though.

    Simon

  3. #3
    Member tunedportcj5's Avatar
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    Thanks Simon, what PIDs would you recommend me logging for idle fuel, spark, etc...?
    '94 Lexus SC300 LY2 4.8, LS6 cam/springs, E38, LS3 MAF, LS2 intake, 88mm TB, 2bar MAP, T42/4L80e, mpt70
    www.terratraction.com/gallery

  4. #4
    Lifetime Member swingtan's Avatar
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    RPM,
    ETCTP,
    MAP,
    VSS,
    SPARKADV,
    IVLVTMP,
    IAT,
    AFRATIO_DMA,
    APCYL_DMA,
    MAFFREQ2
    MAF,
    WO2AFR1
    HO2S11,
    HO2S21,
    SHRTFT1,
    SHRTFT2.

    That should do it for starters....

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