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Thread: Rough RPM Signal/Trace

  1. #1

    Default Rough RPM Signal/Trace

    I've posted about this before, and read a few other threads about this, but haven't seen a resolution. Truck has an HP, V2 software. First install ran a Ford TFI, now a Holley Dual Sync. TFI at first without, then with a Crane HI6 CD box, the CD box with the Holley distributor. Same results with either ignition. I've tried moving power/ground to different locations, no change. What's strange is the Auto Meter tach is nice and steady, it getting a signal from the HI6 box. The trace from the datalog below is what the ECU is using, you can follow it on the fuel and spark tables, and it's all over the place. I had to raise the RPM limit to 7200K, should be at 6500K, to prevent it from being activated at the big end on a track pass. Is this a V2 thing? I don't see how it's an installation problem, since I can't seem to effect it with changes. I plan to step up to newer software over the winter, but my 5.7" Dash is holding me back. I read of issues when trying V4 with it. Would love to hear some ideas!
    Last edited by bWright; 11-04-2019 at 10:37 AM.
    '95 Lightning,351W,10.26/134,4280lbs

  2. #2


    Made a bit of an improvement. Larger ground lead from alternator frame to engine block, and isolated the coil primary wires from the CD box. Better, but still not as clean as I want:
    '95 Lightning,351W,10.26/134,4280lbs

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