The Holley 2245 choke uses what is called a divorced choke thermostat. The thermostat coil sits into the intake manifold and heat from the manifold controls the thermostat opening and closing.
When the engine is cold the thermostat will cause the choke valve to close, which produces a richer gas/air mixture the engine needs to get started. As the valve closes, the fast idle cam moves the fast idle screw to a higher spot, thus increasing the RPM.
As the engine warms up, the thermostat will cause the choke valve to open and the fast idle cam will drop to a lower position.
The only part that make the choke valve move is the thermostat spring. Be sure none of the choke parts are binding and the choke valve opens and closes easily.
You will sometimes need to open the throttle up a bit to allow the choke valve to move.
Holley 2245 Choke Nomenclature
2245 Choke Circuit
Pull Down Adjustment