Specifications

AIR INJECTION SYSTEM - CARBURETED

Article Text

1984 Mazda RX7

For iluvmyrx7.com

Saturday, June 08, 2002 10:42PM

ARTICLE BEGINNING

1984 Exhaust Emission Systems

CARBURETED MODELS

AIR INJECTION SYSTEM

DESCRIPTION

This system controls CO, HC and NOx emissions by injecting

secondary air into the exhaust system to cause further burning of

exhaust gases. System consists of an air pump, 2 check valves, an air

control valve, relief solenoid valve, switching solenoid valve, heat

hazard sensor and catalytic converters.

Air is drawn from the clean side of the air cleaner by the

air pump and directed to the air control valve under pressure. From

the air control valve, secondary air is directed (by the switching

solenoid valve) "downstream" to the pellet converter or "upstream" to

the exhaust port.

The secondary air system contains 2 check valves to prevent

exhaust gas from leaking back into the air pump. The switching

solenoid valve directs secondary air through the air control valve

"downstream" and/or "upstream", based upon engine temperature,

manifold vacuum and engine speed.

The relief solenoid valve controls the amount of air injected

according to intake manifold vacuum. Under normal operating

conditions, part of the secondary air supplied by the air pump is

directed back to the air cleaner. The heat hazard sensor lights an

exhaust temperature warning light on the instrument panel if exhaust

temperatures become excessive.

Fig. 1: Mazda RX7 Air Injection System

TESTING

AIR PUMP