Any Problems with Fuel Pressure Regulator(2006 R12RT)

Having some problems and have pretty well isolated it down to the Pressure Regulator Diaphragm. Intermittent rough idle/stall and an intermittent, massive hiccup under sharp throttle input(passing acceleration)Worse on incline/climb. GS911 indicates no faults or problems. Plugs,wires etc. seem fine. Have been variously switched out. Problem seems common to both cylinders, not one side or other. Steppers set and normal. Gets better the longer it is ridden, and improves under heavy PEA Fuel Additive. At times, runs absolutely perfect. Bike 107k miles on it. I think the Pressure Regulator Diaphragm is likely gone hard and inflexible and is sticking under sudden throttle demand. When I say comes and goes and Intermittent, I mean can be for for weeks at a time good or bad, especially on regular 15 minute commute. Ride it 75 miles or more and it improves quite a bit. Dump in some cleaner and run it 150 miles and it clears up pretty well. A couple of days of commuting and it is back to the problem. It sat for about 6 weeks and ran like a dream for two days and then back again.

Unless you have put a pressure gauge on the fuel system, you are just guessing. It is a very unlikely failure.

I rode around for a day on an F800GS with a fuel pressure gauge installed to isolate a problem. In that case, it was the pump (the F800 works differently than the boxers).