Air Injection System: Operation

Air is drawn from clean side of air cleaner by air pump and directed under pressure to air control valve. The No. 1 relief valve of air control valve diverts part of air pump air back to air pump when engine is operating under heavy load conditions.

The No. 2 relief valve of air control valve regulates the amount of air injected, based upon intake manifold vacuum and coolant temperature. The No. 2 relief valve is used only with automatic transmissions.

The air switching valve of air control valve directs fresh air from air pump either "up-stream" to exhaust ports and/or "downstream" to catalytic converter according to intake manifold vacuum and coolant temperature. The air injection system also contains thermo valves, delay valves, check valves and a vehicle speed sensor to control and protect the air injection system.