All Other Models
- Warm engine to normal operating temperature. Stop engine. Disconnect air control valve-to-intake manifold hose (below No. 1 relief valve) and air control valve-to-catalytic converter hose (bottom of air control valve) from air control valve. Disconnect vacuum sensing tubes from No. 1 and No. 2 relief valves. Disconnect and plug vacuum sensing tube from air switching valve diaphragm.
- Start engine and run at idle speed. Place finger over air control valve outlet ports, air should not be discharged from either port. Using additional tubing, connect intake manifold vacuum directly to air switching valve diaphragm. Air should be discharged from air control valve outlet port (below air switching valve). If air switching valve does not respond as outlined, replace air control valve assembly.