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Mazda RX7. Manual - part 29

A - ENGINE/VIN ID

Article Text (p. 2)

1983 Mazda RX7

For www.iluvmyrx7.com

Sunday, August 26, 2001 05:51PM

35 * Convertible

8 Modification Code
1 * Not Specified By Manufacturer

9 VIN Check Digit
1 * Constant For All Models

10 Vehicle Model Year
D * 1983
E * 1984
F * 1985
G * 1986
H * 1987
J * 1988

11 Assembly Plant
0 * Hiroshima, Japan

12-17 Serial Number
* Sequential Production Number

END OF ARTICLE

AIR INJECTION SYSTEM

Article Text

1983 Mazda RX7

For www.iluvmyrx7.com

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

AIR INJECTION SYSTEM

Article Text (p. 2)

1983 Mazda RX7

For www.iluvmyrx7.com

Sunday, August 26, 2001 04:57PM

sensor as described in "Mazda RX7 Deceleration Control
System" article in this section.

AIR PUMP TEST

1) With engine at normal operating temperature, inspect all
hose connections for leaks. Check for pump noise and belt tension.
2) Stop engine and disconnect air line at air control valve.
Connect hose to a pressure gauge. Connect tachometer to engine.
3) Start engine and run at idle speed. Gauge should register
more than 1.64 psi (.12 kg/cm

) with engine at 800 RPM. If pump

pressure is below specification, replace air pump.

CHECK VALVES TEST

1) Check valves are located at the air control valve exhaust
port outlet and in the air supply line between the air control valve
and pellet converter.
2) To test exhaust port check valve, detach air pump-to-air
control valve hose at air control valve. To test converter check
valve, detach air control valve-to-pellet converter hose at air
control valve. Test each valve separately using the following
procedure:
3) With engine at normal operating temperature, connect
tachometer to engine. Detach hose for valve to be tested. Start
engine and increase engine speed to 1500 RPM. Watch for exhaust leak.
If leak exists, replace check valve being tested.

AIR CONTROL VALVE TEST

1) 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.
2) 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).
3) Using rubber hose, by-pass relief solenoid valve by
connecting vacuum lines on each side of relief valve together. See
Fig. 2. This will cause manifold vacuum to be routed directly to air
control valve.
4) 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.
5) 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).
6) Place finger over air cleaner-to-air control valve hose;
air should escape through hose. Reconnect switching solenoid valve
vacuum tube.
7) Air should not escape at air cleaner-to-air control valve

AIR INJECTION SYSTEM

Article Text (p. 3)

1983 Mazda RX7

For www.iluvmyrx7.com

Sunday, August 26, 2001 04:57PM

hose. If air control valve does not respond as described, replace air
control valve.

Fig. 2: Hose Arrangement for Checking
Air Control Valve Operation

RELIEF SOLENOID VALVE TEST

1) Disconnect vacuum sensing tubes from relief solenoid
valve and vacuum pipe. Blow through solenoid valve from vacuum
sensing tube "B" in Fig. 3. Air should pass through valve and escape
from front port.
2) Disconnect electrical connector from relief solenoid
valve and connect battery power to solenoid terminals. Blow through
vacuum hose again. Air should pass through valve and escape through
air filter. If valve does not respond as described, replace valve.

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