Testing

Fig. 25 Evaporative emission control system.:

1. Warm engine to normal operating temperature, then remove air cleaner cover and filter.
2. Start engine and check for air suction noise from air suction port at idle. Bubbling noise should be heard.
3. If bubbling noise is not heard, disconnect No. 5 hose from air suction valve and check for vacuum.
4. If there is vacuum, replace air suction valve and repeat test.
5. If there is no vacuum, reconnect No 5 hose and refer to Fig. 25 in ``Feedback Control System'' section.
6. Raise engine speed to above 2000 RPM. There should be no bubbling noise.
7. If bubbling noise is heard, disconnect No. 5 hose from air suction valve and check for vacuum.
8. If there is vacuum, refer to Fig. 25 in ``Feedback Control System'' section.
9. If there is no vacuum, replace air suction valve and repeat test.