magneto check on run up with dual EDIS ?
 

I am running dual spark with two separate EDIS modules and two coil packs in my 3.2SS SC

I would like to be able to do ignition check similar to as I am used to in an airplane. In an airplane under the run-up with engine at 3000 rpm, swith off one ignition system then the other and compare rpm drop. Any defect spark plug or malfunction will be easily detected.

How to do this with a dual EDIS setup running on 1 ECU and on 1 VR sensor ?

I was thinking two switches taking out earth to a relay supplying power to either the EDIS modules or the coil pack but this will not work when one module is slave

Any advice ?

Interrupt the PIP signal going from ECU to Pin1 of the EDIS controller.

Though this will put the EDIS in limp mode at fixed 10deg timing.

You could also interrupt 12V power to the individual coil packs.