One other thing....The signal is going to be upside down as the firing is negative. You could use a math channel to invert it or simply create the custom probe for it that will invert it for you.
I would use more screen time at first with no trigger until you can see what you are working with. Then adjust to suit your viewing pleasure
_________________
Tom Roberts
(The Picotologist) http://www.autonerdz.com
skype: autonerdz
THE PicoScope Automotive Authority
In North America