Dynasty L4-153 2.5L SOHC VIN K TBI (1992)
Idle Speed/Throttle Actuator - Electronic: Testing and Inspection
Note:
Idle Air Control (IAC) motor operation can be tested using exerciser tool (7558).
CAUTION: Proper safety precautions must be taken when testing the IAC motor.
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Set the parking brake and block the drive wheels
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Route all tester cables away from the cooling fans, drive belt, pulleys. and exhaust components
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Provide proper ventilation while operating the engine
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Always return the engine idle speed to normal before disconnecting the exerciser tool
1.
With the ignition OFF, disconnect the IAC motor wire connector at throttle body.
2.
Plug the exerciser tool (7558) harness connector into the IAC motor.
3.
Connect the red clip of exerciser tool (7558) to battery positive terminal. Connect the black clip to negative battery terminal. The red light on the
exerciser will flash when the exerciser is properly connected.
4.
Start engine. When the switch is in the HIGH or LOW position, the light on the exerciser tool will flash. This indicates that voltage pulses are
being sent to the IAC stepper motor.
5.
Move the switch to the HIGH position. The engine speed should increase. Move the switch to the LOW position. The engine speed should
decrease.
a.
If the engine speed changes while using the exerciser tool, the IAC motor is functioning properly. Disconnect the exerciser tool and connect
the IAC stepper motor wire connector to the stepper motor.
b.
If the engine speed does not change, turn the ignition OFF and proceed to step (6). Do not disconnect exerciser from the IAC stepper motor.
6.
Remove the IAC stepper motor from the throttle body.
CAUTION: When checking IAC motor operation with the motor removed from the throttle body, do not extend the pintle more than
6.35 mm (.250 in).
If the pintle is extended more than this amount, it may separate from the IAC stepper motor. The MS motor must be replaced if the pintle separates
from the motor.
7.
With the ignition OFF, cycle the exerciser tool switch between the HIGH and LOW positions. Oh serve the pintle. The pintle should move
in-and-out of the motor.
a.
If the pintle does not move, replace the MS motor. Start the engine and test the replacement motor operation as described in step (5).
b.
If the pintle operates properly, check the MS motor bore in the throttle body bore for blockage and clean as necessary. Reinstall the IAC
motor and retest. If blockage is not found, refer to the Diagnostic Charts.
