pardon the ignorance chaps, but the way i understand it, we currently have two coils, both sending power to the distributor cap. The dizzy then 'distributes' this spark to both the leading and trailing wires.

from diagrams i've seen of the 2nd gen mod, the trailing wires are left untouched...ie the coil goes to the dizzy goes to the plugs. thats fine.

the diagrams then show the mod done to the leading wires whereby the coil 'power' wires are removed from the coil and connected to the 2nd gen ignitor and the ignitor in turn connects to the two spark plugs

my question is therefore ; what tells the ignitor when to fire ?

 

you still wire the 2nd gen coil and igniter to the leading J109 igniter on the dizzy. it recieves its signal from it tellling the 2nd gen coil when to discharge to the plugs wires