Air Injection: Testing and Inspection

Air Injection System Test

HOT ENGINE
1. Remove the air cleaner cover and filter.





2. Start the engine and check for air suction noise (bubbling noise) from the air suction port at idle.

Bubbling noise should be heard at idle.





- If bubbling noise is not heard, disconnect # 5 hose from the air suction valve and check for vacuum.
- If there is vacuum, replace the air suction valve and retest.
- If there is no vacuum, reconnect # 5 hose and go to output troubleshooting.
4. Raise the engine speed above 2,000 rpm.

There should be no bubbling noise above 2,000 rpm.

- If a bubbling noise is heard, disconnect # 5 hose from the air suction valve and check for vacuum.
- If there is vacuum, go to output troubleshooting.
- If there is no vacuum, replace the air suction valve and retest.