Thanks everyone for responding.

David (Davies)

Thanks for that snippet of info, very interesting! A nice fella called Tim Bowkett suggested last night that this "dual trigger" capture was infact normal. I didn't know it was such a widely used technology though.

Anyway armed with the understanding that the capture I had made was not actually a problem, I decided to retrace my earlier diagnostic steps. As suggested also by Tim, I took the opinion that the coil energy was being discharged straight to ground. It appears that I may have been a bit a little hurried in my decision that the spark I saw when I tried a new coil, lead & plug was weak. So I tried a new set of plugs in it today.

How deeply embarrassing! It started straight up, nice & clean on all four. My excuse is that I was thrown off course by the unusual capture. Sorry to waste your time folks. & well done Derek!

It is strange that it was a runner when it came in to us. I am wondering if the plugs were contaminated when the machine shop skimmed the head. Maybe the machining fluid had left a conductive residue on the plugs? Any thoughts?

Here is the way it looked when running……….

Here is a known good crank/Cam reference signal.........

Same again but a little closer..........

Hopefully others have learned a little too.

Cheers all

Dave (Hill)