That is a very well explained operational sequence, and I think I actually grasp it now. I had guessed that there had to be some type of electric clutch on the butterfly because if you shut everything off and move the throttle linkage it opens and closes like a "normal" setup. I had stated in another post that I consider a design as complicated as this (just to open the throttle) an over engineered "kluge" and I am glad my Bimmers don't have it. But then, I don't care for "fly by wire" aircraft either (A-300, Paris Air Show crash). Years ago I worked for the Seeburg Jukebox Company. Their motto: Simplicity, reliability, endurance. That works for me. Thanks for your comments.

Garry