Timing Mark not showing up??

Some (many?) of the pickups are directional. Suppoose if hte arrow points the opposite way it might not trigger consistantly.

Doubt it has anything to do with the coil. A test light at best can show there is power getting to the coil. It will be low because the power goes through the ballast and more so with the engine off sincepower supply is at 12.6 Volts rather than 14.3 Volts.