ignition problems with MS II on a Vauxhall

[nico]

hello
i m using a MS II V3 with megatune 2.25 beta V2.34 in a vauxhall nova 1300cc wich monitore the injection and the ignition
no problems with the injection (throttle body) but since the ignition gestion, the motor doesn't start anyway ...
i have ignition but the frequency looks too weak
here are the parameters;
trigger offset 10 ms
skip pulses 3
predictor algorithm last interval
predictor gain 20%
next pulse tolerance
cranking 50%
after start 75%
normal running 25%
ignition input capture rising edge
cranking trigger trigger rise
coil charging scheme standard coil charge
spark output going hight ( inverted)
max spark duration 2 ms
max dwell duration 2.5 ms
i trigge from a vr sensor wich is 10° bdtc
what do you think?
so when i compare with another motor, i find that the frequency of the vauxhall ignitions is not that high
thanks

[nico]

so
i tested the timig light during the cranking
it seems that the sparks aren't regular, i don't know if this is a tuning problem or a assembly problem
thanks

[grippo]

It sounds like the tach signal is noisy. All the code does during cranking with trigger rise is to immediately fire the spark plug whenever it gets a tach input - not a lot to go wrong as long as it sees a good tach input. So, I would read up on and check, on the software side, my trigger rising/ faling edge setting, sparking polarity, cranking rpm input and maybe try increasing the coil duration a bit. On the hardware side, check all the connections, grounding , board soldering , etc. If you have a scope, use it to look at the trigger input into the MS. If it is erratic, the spark output will be erratic. If it is clean, but your spark output is erratic, then you probably have a problem on the board.

Once you get past the cranking stage, it may help to use the 2nd deriv prediction/ 1st deriv above 7500 rpm.