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Thread: Alpha N (TPS Load) help... noisy TPS signal?

  1. #1
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    Default Alpha N (TPS Load) help... noisy TPS signal?

    I've been tuning this way cool BMW with LS1 swap, and individual runner intake. Due to the intakes design, we ran into some strange fueling issues in MAP load based VE, so we went to a Custom Calibration with the TPS% as load.

    Now, I have a different issue.... under 20%, the TPS signal is not linear, or is noisy... or plain reads funny.

    It may be idling at 0% tps, then he adds a bit of throttle, and it may go to 8%, then more throttle, and the logged signal bounces vigorously, or may even go back to zero etc. It seems to clear up somewhere around 20%.

    AS you can imagine, it makes getting the fueling correct under 20% very difficult.

    I had him replace the TPS sensor last week, to no avail.

    Suggestions?

    and actually, THIS particular car would run ok with MAP upto this 20% tps mark, but there is no way to do this (you can switch to MAP above a certain MAP, not under).

    Also, is there a baro correction screen I am not seeing for when running TPS mode? Would seem to me that if the air is 5% better, you would want 5% more fuel....

    Thanks for any tips/comments.

  2. #2
    Lifetime Member TAQuickness's Avatar
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    First thing that comes to mind is to check the integrity of the wiring and for hysteresis in the throttle linkage?


  3. #3
    Joe (Moderator) joecar's Avatar
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    In addition, after checking the above, check the voltage output of the TPS as you slowly open/close the throttle... the voltage should vary in a smooth manner without any spikes/dips or dead/flat spots.

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    Quote Originally Posted by TAQuickness View Post
    First thing that comes to mind is to check the integrity of the wiring and for hysteresis in the throttle linkage?
    What do you mean by the latter?

  5. #5
    Lifetime Member TAQuickness's Avatar
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    Mechanical slop.


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