Only runs 40 Degrees advanced
With efi engine, pull injector power relay, efi connector, or injector connectors, disabling injectors. I wire my cars to make it easy.. Then crank for testing ignition. Also ground plug wires, or coil to cap wire. Clamp-on timing lights trigger on current, not voltage. It is a way to get around an electrical noise, and safety issues. The timing lights can be used on distributor to observerify rotor and pickup/reluctor positions. There will be 4 cylinder observation per engine revolution, with cla,p at coil hv, but you can visually sort out @ #1.
MSD CDI often generates electrical messing with efi measurements and ignition triggers. Recently a member had problems with coils, and found balast resistor addition helped. It helped likely, when current reduction reduced electrical noise. I am sure by the time noise is reduced, an inductive hei would be superior.
Please be safe, do not repeat hand spinning, with sparks and fuel spurting....