240Z w/ ZX Dist.E12-80 - Unable to get spark at coil

[NCZZZ]

71 240Z with 2.8 F54 .040 / N42 Head / Stage 3 Cam / SU Carbs / Upgraded Alternator & Lighting relays

 

The PO of the car already had the ZX distributor installed. It was utilizing a stock 240Z coil and the ballast resistor. It ran, tach worked -- no reason to really unwrap and look at wiring.

 

Recently went on a road trip and the car was "stumbling" terribly under load (acceleration, climbing a hill, etc.). It seemed to also coincide with the tachometer needle "bouncing" wildly.

 

Started checking things out this week -- then the car would not start. Found I had no spark from the coil (checked at coil and end of dist wire). OK, coil must have been going out causing "stumbling".

 

Picked up a new 12V coil (this time the required type for ZX). Unwrapped the wiring to the IC Module and found they had connected the wire that is supposed to go straight from the '+' side of coil to terminal 'B' on the IC module to the side of the ballast resistor with the B/W wire instead ( I believe this would be the 12V power from the ignition switch). It wasn't passing through the resistor. I guess this was ok.

 

I ran a wire from '+' at coil to 'B' on IC Module and from '- 'at coil to terminal 'C' on the IC module. Bypassed the resistor by connecting the B/W & G/W wires together.

 

I still get no spark from coil.

 

With key 'on' 12.6V at '+' coil and '-' coil. When cranking this voltage drops from 12.6V to 9.9-10.3V. Measured at '+' terminal at starter solenoid same thing - voltage drops to ~ 10V. Measured through fusible link - 12.6V until cranking. Measured at ignition switch 12.6V until cranking it drops to 10.3V.

 

All connections are good (new connectors), new fusible link with new connectors. Voltage drop cause undetermined.

 

Is this voltage drop enough to cause the coil not to fire?

 

Could the E12-80 IC module have been damaged by running it onto the ballast resistor?

 

If the E12-80 module was bad, would this cause no spark from coil?

 

I am certainly no expert and I am certainly at a loss. Any help would be appreciated.

[NCZZZ]

UPDATE

 

After more investigating, I found the rotor button had alot of carbon build-up. I cleaned it and the car started immediately. If I am correct, if the distributor cannot transmit the coil output the coil will not fire. IE with a points set-up when the points open this allows the coil to send high voltage to the cap/rotor.

 

Regardless, looks like a new cap and rotor are in order.

 

Hope this helps someone else.