Quote Originally Posted by rspears View Post
Mine does that too, Bob, and I can hear the idle air controller "sipping" in time with the surge, but a throttle blip generally makes it go away immediately other than on a very cold day when it may have to warm up for a few minutes to settle into a clean idle.
Greg mentioned that idle "sipping" noise too.........apparently my propeller induced hearing impairment can't detect that sound. I haven't had enough operating cycles to detect any repeatable pattern of behavior yet so I guess time will tell.