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Thread: Odd Fire TBI

  1. #91
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    I have not tried to operate an OBDII controller without spark. With no further information I would suspect the spark outputs will not affect fuel outputs. Batch fueling is the default when the CAM sensor signal is not present. the ECM number chosen could determine whether or not electric fans are an option.

    So:
    Disable all transmission codes.
    Disable any ignition output codes.
    Disable any misfire codes.
    Disable any catalytic converter codes.
    Disable any Post Cat O2 codes.
    Set cam signal codes to "Type C" or "Type D" to ensure batch fire becomes active.
    Ensure injectors are correct type and set flow accordingly
    Set cylinder volume accordingly.
    Adjust fuel delivery during priming, cranking, and low speed operation

    I would expect to tune the speed density tables as they are used for cranking and low speed engine operation and may be used for acceleration enrichment. You may need to adjust the MAF transfer curve to provide optimum performance.

    It is possible to use a 16197427 OBDI ecm with MAF if you use modified code. Maybe that is not a useful alternative?

  2. #92
    Carb and Points!
    Join Date
    Sep 2019
    Posts
    2
    Quote Originally Posted by 1project2many View Post
    I have not tried to operate an OBDII controller without spark. With no further information I would suspect the spark outputs will not affect fuel outputs. Batch fueling is the default when the CAM sensor signal is not present. the ECM number chosen could determine whether or not electric fans are an option.

    So:
    Disable all transmission codes.
    Disable any ignition output codes.
    Disable any misfire codes.
    Disable any catalytic converter codes.
    Disable any Post Cat O2 codes.
    Set cam signal codes to "Type C" or "Type D" to ensure batch fire becomes active.
    Ensure injectors are correct type and set flow accordingly
    Set cylinder volume accordingly.
    Adjust fuel delivery during priming, cranking, and low speed operation

    I would expect to tune the speed density tables as they are used for cranking and low speed engine operation and may be used for acceleration enrichment. You may need to adjust the MAF transfer curve to provide optimum performance.

    It is possible to use a 16197427 OBDI ecm with MAF if you use modified code. Maybe that is not a useful alternative?
    I have since tested a P01 with a v6 calibration on the bench and even without a cam sensor it still fires sequentially.
    I gave up and ran a microsquirt.

  3. #93
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    Lakes Region, NH
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    Interesting. Factory service literature says otherwise so thanks for the feedback. I don't blame you for stopping the fight.

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