Air Injection: Testing and Inspection

THERMOVALVE C

1. Ensure engine coolant temperature is below 122 deg. F.
2. Attach suitable vacuum gauge to thermovalve C on 1984 model. Vacuum should be present at idle.
3. If vacuum is present on 1984 models, proceed to step 5. If vacuum is not present, disconnect second hose from thermovalve C and check for vacuum. Vacuum should be present.
4. If vacuum is present, replace thermovalve C and repeat test. If vacuum is not present, check vacuum line to auxiliary intake port of valve for leaks or blockage. If satisfactory, replace cranking solenoid valve and repeat test.
5. On 1984 models, stop engine and ground coil secondary wire to prevent engine from starting, then turn ignition switch to START position.
6. Check for vacuum at valve. Vacuum should not be present with ignition switch in START position.
7. If vacuum is present, replace cranking solenoid valve and repeat test. If vacuum is not present, proceed to step 8.
8. On all models, start engine and allow to reach normal operating temperature.
9. Attach vacuum gauge to inner hose fitting of thermovalve C on 1984 models and check for vacuum. Vacuum should not be present.
10. If vacuum is not present, test is complete. If vacuum is present, replace thermovalve C and repeat test.

AIR SUCTION VALVE

1. Remove air cleaner cover and filter, then start engine and allow to reach normal temperature.
2. check for a bubbling noise from the air suction port at idle, located in lower portion of air cleaner assembly. A bubbling noise should be heard.
3. If bubbling noise is heard, proceed to step 11. If bubbling noise is not heard, disconnect hose No. 5 from air suction cut-off diaphragm and check for vacuum.
4. If vacuum is present, replace air suction cut-off diaphragm and repeat test. If vacuum is not present, reconnect hose No. 5 andproceed to step 5.
5. Disconnect hose No. 32 routed from control box at vacuum hose manifold then check for vacuum at vacuum hose manifold. Vacuum should be present.
6. If vacuum is not present, check vacuum line No. 32. If satisfactory, replace air bleed valve B and repeat test. If vacuum is present, check voltage at air suction control solenoid valve.
7. If voltage is present, replace air suction control solenoid valve and repeat test. If voltage is not present, proceed to step 8.
8. Inspect vacuum switch C for proper operation, replace as required.
9. Check for voltage at control unit black/yellow wire connector with ignition switch On. If voltage is not present, check wiring for damage or defects.
10. Check for continuity between control unit brown/black wire and suitable ground. Continuity should be preset.
11. Raise engine speed above 3500 RPM. A bubbling noise should be heard from air suction port.
12. If a bubbling noise is not heard, proceed to step 14. If a bubbling noise is heard, check for voltage at air suction control solenoid valve.
13. If voltage is not present, replace air suction control solenoid valve and repeat test. If voltage is present, refer to steps 8 through 10.
14. Heat air bleed valve to approximately 140 deg. F. with a suitable hot air gun. Bubbling noise should stop at idle.
15. If bubbling noise stops, test is complete. If bubbling noise does not stop, replace air bleed valve B.