inconsistant timing

[Edd]

Guys,

I have an ignition software problem. I have a 85 camaro with a 305 engine. Ignition works fine i've got a descent ms2 controlled spark. But i cant get the timing right.

For RPM i'm using 4 magnets on the flywheel and a hall sensor as a pickup, signal is clear in logfiles, hence the descent spark. I've been told to put the first magnet about 45 deg btdc to give the ms some calculation time. and the same 45 must be entered at the trigger angle/offset in tunerstudio.

tested it using a timing light during cranking and it lit up at 1 deg btdc. So i adjusted the trigger angle/offset to 55 because in the logfile ms was igniting 10 deg btdc. cranked again and it lit up at 6 deg atdc. So i thought wrong way around... thus i set the trigger angle/offset to 28 cranked again no tdc point anywhere near when the light flashed. so I thought roter phasing probably wrong. turned the dizzy a bit anti-clockwise. cranked again, and when the light flashed it showed about 18 deg btdc. seems right but still not the same as what ms is supposed to (10deg btdc shown in the log file). last attempt i'v set the offset angle to 38, cranked and it at the flash it was about 3 deg btdc. This doesn't make any sense right?

summarising:
between attempt 1 and 2 trigger offset was changed 10 deg, result was 7 deg change in Crank angle
between attempt 2 and 3 rotor phasing probably wrong
between attempt 2 and 4 trigger offset was changed 27 deg, result was about 24 deg change in Crank angle.
between attempt 4 and 5 trigger offset was changed 10 deg, result was about 15 deg change in Crank angle.

what could cause this non-consistency between the change in trigger offset and resulting change in crank angle...? mechanical advance in the dizzy is fixed...

Am i missing something?

Edd

[kjones6039]

It might be interesting, (to me anyway) to see your msq and cranking log.........

Ken

[Edd]

here is a cranking log.

Edd