AIR INJECTION SYSTEM
Article Text
1983 Mazda RX7
For www.iluvmyrx7.com
Copyright © 1998 Mitchell Repair Information Company, LLC
Sunday, August 26, 2001 04:57PM
ARTICLE BEGINNING
1983 Exhaust Emission Systems
MAZDA RX7 ENGINE 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, monolith converter and pellet converter.
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
Note: Before replacing air control valve, switching solenoid
valve or relief solenoid valve, check auxiliary control
unit, No. 2 water temperature switch, choke switch and
choke relay as described in "Mazda RX7 Auxiliary Control
Device" article in this section. Also, check throttle
To Next Page
