Just trying this now, I've just done a timing calibration again and the difference when swapping from rising to falling is very small 2-5 degrees ( -120 -125 ) , Also hard to tell on the starter motor. Fixed at 10. Still just fires once then stalls when on falling. What am I missing ? ** UPDATE ** Just got this working, I needed to set the dwell to 2.5ms for the MSD DIS-4 unit.. Tested by swapping to 1ms when running , and the engine stalls