Unstable spark timing - SORTED!!!

[Philip Lochner]

Good news chaps!!  Got it sorted last night!!  The MAIN culprit was the "Predictor Algorithm" which defaults to "1st High RPM etc".  The manual says NOTHING about the choices one can make here so I had no reason to change it from the default.  As soon as I set this on "Last interval", timing became rock steady and advanced as per the map as function of RPM.
 
I've got my reluctor wired up so it goes from + to - as the trigger passes the pickup (ie not as it seems it should be as per the "manual discrepancy discussion"). Checked with my scope and the 0-crossing detector and VRout co-incides 100% with the 0-crossing.  Both pots are turned fully counterclockwise so it seems that MS2 is not very sensitive to the bit of noise I have on the VR signal - which is good.
 
Starting still takes longer than with the original dissy but I think the 3 skip pulses is adding to the number of cranking revolutions the car's own ECU let occur before it commences FI.  I understand the idea is to allow oil pressure to build before actually starting the engine. I'm not too concerned about this as I'm rather confident things will improve when I (MS2 rather) take control of FI.
 
Kind regards
Philip Lochner

 

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