cmsprofessor

I have sort of a frankenstein RX7 with a lot of different parts. The basics are a NA Rotary Engineering "Turbo Alternative" 13b. The ignition is one I made from Jeff20B's diagrams of the waste spark system. I have three j-109 igniters firing three Blaster coils. The igniters are mounted on an aluminum heat sink in the air flow in front of the radiator.
A few days ago the car was running very badly with intermittent spark. I pulled the plugs and the front rotor was black with carbon, the rear was tan for the plugs. I put new plugs in and changed the leading coil igniter - all seemed well. This morning, almost to work, the one rotor went out (I assume it is the front igniter again). What could be the problem?

Jeff20B

iTrader: (13)

No heat sink grease? Bad coil that flakes out when it warms up?

cmsprofessor

Thanks Jeff - I did use the heat sink grease but I will take a closer look at the coil. For now it is back on the road with a new igniter.