Auxiliary Air Valve System
NOTE:
Install tachometer when checking auxiliary air valve system. Ensure tachometer is connected to proper terminals. See IDLE SPEED & MIXTURE in articles listed below for tachometer connections:
- ADJUSTMENTS - 4-CYL
- ADJUSTMENTS - V6CAUTION: Some tachometers may not be compatible with ignition system. Consult tachometer manufacturer before connecting tachometer to system. To avoid possible damage to ignitor and/or coil, DO NOT allow tachometer terminal to become grounded.
- Install tachometer. With engine coolant temperature less than 176°F (80°C), start engine.
- With engine idling, turn idle speed adjusting screw inward to bottom of bore while counting number of revolutions. See Fig 1 and Fig 2. Engine speed should decrease noticeably.
- Return idle speed adjusting screw to original position. Warm engine to normal operating temperature. Repeat step 2). Engine speed should not change or should drop slightly.
- If engine RPM does not respond as indicated, check for vacuum leaks or restricted auxiliary air valve circuit. If no defects are found, replace auxiliary air valve, located on bottom of valve body.