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Old 04-09-2009, 12:21 AM   #1
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Default rpm spike in MS

y did my rpms spike in my datalog???
obviously my engine didnt do this but my datalog recorded it some how
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Old 04-09-2009, 07:43 AM   #2
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It,s a problem that seems to be affecting more and more people using MS. Basically the MS doesn't like the miata CAS and the blip is just due to MS not being able to decode the CAS signal properly.

If it only happens occasionally then don't worry about it but if like Joe and myself its frequent and intolerable you may have to switch to a 36-1 trigger system.
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Old 04-09-2009, 09:06 AM   #3
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Install a .1uf capacitor between JS8 and ground.

If it persists, you might run a new wire from the MS to the CAS, specifically using shielded cable (such as mic cable) with the shield grounded and the center pair carrying the two signals. I have a hunch that the noisy, high-current injector lines (which run in the same bundle) are partly to blame for this in some cars.

If it still persists, then yeah, a new CAS may be in your future. Or a crankwheel.
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