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MegaSquirt losing crank signal

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    MegaSquirt losing crank signal

    I recently installed a new 2.9L M20 with Microsquirt v3.0. I'm using the stock 60-2 toothed wheel and having an issue with the crank position sensor at higher RPMs. Once I hit around 3500 RPM, the engine acts like it's bouncing off a rev limiter/fuel cutoff. The tooth logger shows I'm completely losing the signal and counts as a loss of sink. I bridged the shunt resistor in the case, moved the CPS bracket closer to the wheel, and swapped out CPS sensors with another used one.

    Any ideas what I should try to check next?

    1988 E30 325iC

    Do you have a new sensor? I have heard MS is pretty picky and that they benefit from having a Bosch sensor. I have seen others use a decent brand one, but swap to a new Bosch and the issue is resolved.

    At a guess though.
    20% Accurate

    Morty: Well Summer maybe people that create things aren’t concerned with your delicate sensibilities you know? Maybe the species that communicate with each other through a filter of your comfort are less evolved that the ones that just communicate? Maybe your problems are your own to deal with and maybe the public giving a shit about your feelings is a one way ticket to extinction.


      Try swapping in a new harmonic balancer. If that doesn't work, try a new engine harness.
      AWD > RWD


        Not sure if you're still wondering about the issue but here's a related thread:

        Im having the same issue right now with a whodwho megasquirt.


          would have thought that it would be more robust
          89 E30 325is Lachs Silber - currently M20B31, M20B33 in the works, stroked to the hilt...

          new build thread