New to me FD, uncovering some gremlins.

The car is about 200 miles into a fresh rebuild from IRP. Single turbo setup from IRP w/ PowerFC and IRP IGN-1A ignition system.

I've encountered a rather strange problem where the engine runs on the rear rotor only. Idle is quite rough, and unplugging the leading or trailing coils does not change idle at all.

The leading and trailing coils will fire a spark plug outside of the car when it's running - so it seems like coils and coil wiring is okay. I've also verified good compression on the front rotor.

The only common thread I can think of for the first two coils is the ground - the IRP harness has a ground on the rotor housing. This seems to be okay though if plugs fire outside the car?

Pretty stumped on this one, not sure where to look next.

 

Unplugging coils is a good test, but that doesn't quite guarantee there was a spark problem. Are you smelling unburnt fuel in the exhaust? Are the front rotor's spark plugs wet with fuel?

 

Yes and yes. Also my timing light does not fire on either of the rotor 1 wires, but fires fine on the rotor 2 wires.

I'm suspecting there're some wiring problems - the stock harness looks like it's been hacked into a few times. This will likely result in expediting my plans for a fresh harness.

The IRP IGN-1A kit looks pretty simple to bypass the factory ignitor wiring altogether, so I'll probably start there.