See Figure 1
The idle air bypass valve is used to control engine idle speed and is operated by the computer control module, or in response to engine coolant temperature change, depending upon vehicle application. The valve allows air to flow into the intake air stream to control cold engine fast idle, no touch start, dashpot, over temperature idle boost and engine idle load correction. The air bypass valve, which is used on all EFI and SEFI systems, is located on the throttle body housing.
- Make sure the ignition is in the OFF position.
- Disconnect the air bypass valve.
- Use an ohmmeter to measure the resistance between the terminals of the valve solenoid.
Due to the diode in the solenoid, place the ohmmeter positive lead on the VPWR pin and the negative lead on the ISC pin.
- If the resistance is not between 7-13 ohms, replace the air bypass valve.
REMOVAL & INSTALLATION
- Disconnect the negative battery cable.
- Disengage the idle air bypass valve electrical connector from the wiring harness.
- Remove the two retaining screws, then remove the idle air bypass valve and gasket assembly from the vehicle.
If scraping is necessary to clean the gasket mating surfaces, be careful not to damage the air bypass valve or throttle body gasket surfaces or drop any material into the throttle body.To install:
- Make sure the gasket mating surfaces are clean. Install a new gasket on the throttle body surface, then mount the valve assembly. Secure using the two retaining screws tightening them to 84 inch lbs. (9.5 Nm).
- Engage the idle air bypass valve electrical connector to the wiring harness, then connect the negative battery cable.