Ranger 2WD V6-177 2.9L (1989)
Idle Speed/Throttle Actuator - Electronic: Description and Operation
Fig. 1 Air bypass valve assembly
The air bypass valve solenoid, Fig. 1, is used to control engine idle speed and is operated by the EEC-IV control module. This valve allows air to pass
around the throttle plates to control, cold engine fast idle, no touch start, dashpot, over temperature idle boost and engine idle load correction.