When the engine is warmed up and idling, it is in what is called a "closed loop" operation. You can read all about the wonderful world of stepper motors in a service manual, but basically there are about 4 "open loop" modes in which the stepper motor will be adjusting the carb--a cold engine (or at least cold outside air), Wide-open-throttle (flooring it), drops in manifold vacuum (stomping the gas, but not quite flooring it), and another one I can't remember--something about fluctuations in timing or something.
The easiest way to make sure it's working is to look down the carb when the engines warmed up and idling, then punch the gas lever and the little rod inside the carb should slide back in the direction of the rear of the vehicle. It will then slowly slide forward as the condition disappears.
Currently an '86 CJ-7 and a '77 CJ-7 Golden Eagle---#4 and 5 following a '01 Sahara, '90 Sahara, and '85 CJ-7....