Why does the valves open and close too slowly?

a. There is water or oil inside the positioner

To do:

1. Check to see if there is water or oil entrained in the air supply
2. Replace with a new positioner/actuator unit and improve the quality of the air supply

b. The filter regulator is clogged

To do:

1. Check the filter
2. Clean the filter or replace with a new filter