Ranger 4WD V6-171 2.8L (1983)
Idle Speed/Throttle Actuator - Mechanical: Description and Operation
Vacuum Operated Throttle Modulator (VOTM)
Fig. 33 Vacuum operated throttle modulator (VOTM)
The VOTM, Fig. 33, used on some vehicles acts as a variable carburetor stop. The plunger extends when vacuum is applied.