Auxiliary Air Valve System
WARNING: This page is about a different car, the 1993 Toyota 4Runner. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Install tachometer when checking auxiliary air valve system. Ensure tachometer is connected to proper terminals. See IDLE SPEED & MIXTURE in ADJUSTMENTS
article for tachometer connections.
CAUTION:
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 chamber in auxiliary air valve circuit. If no defects are found, replace auxiliary air valve.