Been absent from here and just saw this thread and it sounds like a issue I had not long after I fitted PCV to my bike, there is a set of plugs that comes from PCV that goes down back of motor that intercepts signals from Crank Angle Sensor ( I think, been awhile) any way it places one of the connectors facing in such a way that it can collect water if you accidently spray it in behind the triangle plastic filler panel, it happen twice before I sealed back of PCV plug so water could not dribble down lead and sit in the square female reiever triumph plug causing the disruption to the signal.
So the question I ask is did this start after a washing down of bike or possibly a ride in a heavy down pour.
I actually filled the square receiver plug with dielectric grease and used some silicon to seal the back of male plug, oh it was only ever a drop or two of water either time so it does not take much to upset the signal
Hope this helps
Hans