Intermittent rough idle 12.7 60S

I’m having a issue with my 04 century 12.7 series 60. Idles rough sometimes, now most times. When cold or just starts for the day it idles smooth no problem but as after 5-10 mins starts to idle rough. I wouldn’t describe it as a surge kind of idle, it’s more like a misfire kinda but the intensity changes. It will randomly idle smooth throughout the day. One thing I notice is rough idle is sometimes triggered when the air governor goes off (pssshh). Somehow feel it’s related to the air compressor. New fuel pump, no codes, runs fine and strong otherwise just idles very rough most times. Any ideas is greatly appreciated. Thanks