So l can't decide if l discovered something here.
Timing decided to return to 0° btdc (effectively no signal to ecu) at cold start up.
Because of the camshafts l unplugged the cold start injector.
Once the csi was re-plugged ignition returned to normal.
The 0°btdc seemed random but now, thinking about it, once the engine is warmed up the csi is not used so the ignition signal works as it should.
If this is the case it has nothing to do with the igf signal and Jondee was as ever, totally correct.