Air Control Valve
- After ensuring air pump and all hoses are correct, check carburetor and air control valve attaching nuts for tightness. Warm engine to normal operating temperature. Stop engine and connect a tachometer. Disconnect air cleaner-to-air control valve hose at air cleaner.
- Disconnect both vacuum hoses from relief solenoid valve (Blue color dot). Using rubber hose, by-pass relief solenoid valve by connecting vacuum lines on each side of relief valve together. See Fig 1. This will cause manifold vacuum to be routed directly to air control valve.
- Start engine and run at idle. Place finger over air cleaner-to-air control valve hose and check that air is not escaping through hose. Disconnect rubber hose used to by-pass relief solenoid valve; air should escape at air cleaner-to-air control valve hose. Reconnect by-pass hose at relief solenoid valve.
- Using throttle, set engine speed at 2500 RPM. Disconnect vacuum sensing tube from switching solenoid valve (Gray color dot). Place finger over air cleaner-to-air control valve hose; air should escape through hose. Reconnect switching solenoid valve vacuum tube; air should not escape at air cleaner-to-air control valve hose. If air control valve does not respond as described, replace air control valve.
Courtesy of MAZDA MOTORS CORP.