There's not even a test method or removal method in the fsm. I think there's two photoelectic sensors in the dizzy housing. There's a coarse slotted wheel and a fine slotted wheel, one being the tdc sensor and the other the crank angle sensor. There's not a lot to go wrong with them, sinde the light source is an led and the sensor is a photocell, so I'd recheck the connector in the bottom of the dizzy for corrosion, and check the dizzy guts for dirt on the led/photocell.

The icm you put on is just an electronic switch, a power transistor, the black box on the coil bracket, that turns on and off the coil connection from coil- to ground to trigger the spark. Sounds like time for a junkyard distributor.