nrpetersen
Curmudgeon
Wait a minute! - I should have said what happens when one cylinder dumps unburned fuel into the converter. This would make both cylinders to quickly be remapped leaner - & probably more stumble.I don't think power output vs mixture is that critical - especially in a minimum power situation. More critical is what the map optimization does to both cylinders when only one cylinder is dumping excess oxygen into the converter.
I gotta study & think about the rest of your post
NRP
At any rate, The mass flow to each cylinder vs the milli-volts out of the sole TPS has to be within a fairly small range - whatever that is.
Q - At a typical idle (i. e. against the throttle stops), what is the ratio of butterfly opening area versus BBS metering port area? I frankly don't expect anyone to know this, but that's what I'd like to find out without taking my R1100 down.
Another thought - since we are dealing with the very small angle of TPS motion, could it be that the TPS pot linearity at small angles has something to do with surging too? Film pots do wear, of course and are not particularly durable.