What triggers your unit?
If a magnetic pick-up under the cap, I'd just check that guy or flat replace it. It generates a tiny voltage every time a reluctor vane passes threw it's magnetic field. That tiny voltage is amplified and shaped into something the MSD recognizes, and then fires the coil from it's charged capacitor.
Of course, to do that, the amp needs full-time power from the ignition switch....
and the capacitor needs a clean,dedicated, un-interupted battery supply
Think of the system as having 5 parts;
the trigger
the properly distanced rotating reluctor
the amp
the capacitor, and
the MSD specific coil
the trigger is the weakest link.
