Jeep Wrangler/YJ 1987-1995 Repair Guide

Idle Speed Actuator Motor


The Idle Speed Actuator (ISA) is mounted on the throttle body and controls idle speed and engine deceleration throttle stop angle. The actuator changes the throttle stop angle by being a movable throttle stop. The ECU controls the ISA motor by providing the appropriate voltage outputs to produce the idle speed or throttle stop angle required for the particular engine operating condition. There is no idle speed adjustment.


See Figure 1

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Fig. Fig. 1: Idle speed actuator replacement

The closed throttle switch is integral with the motor.

  1. Disconnect the throttle return spring. Unplug the wire harness connector from the motor.
  3. Remove the motor to bracket retaining nuts. Be sure to use a back-up wrench, as not to remove the motor studs which hold the motor together.
  5. Remove the motor from the bracket.
  7. Installation is the reverse of removal.