Thermostatic Air Cleaner: Testing and Inspection

Fig. 91 Testing HAI System (Cool):

Fig. 92 Testing HAI System (Hot):

1. Remove the air cleaner top cover.
2. Start engine and maintain idle speed.
3. Cool the hot idle compensator (HIC) valve with compressed air.
4. Check that the air control valve closes to cool intake air and opens to the hot air hose coming from the exhaust manifold. Fig. 91
5. Reinstall the air cleaner top cover and allow engine to reach normal operating temperature.
6. Check that the air control valve opens to cool intake air and closes to the hot air hose. Fig. 92
7. If a problem is found, check the air control valve vacuum diaphragm and/or the HIC valve.
8. Repair or replace the hot air pick-up hose, if necessary.