Deceleration Control System; No.1 Anti-Afterburn Valve; Operation - Mazda 1983 RX7 Service Manual

ARTICLE BEGINNING
1983 Exhaust Emission Systems
MAZDA RX7 DECELERATION CONTROL SYSTEM
DESCRIPTION
The Deceleration system is designed to maintain a balanced
air/fuel mixture during deceleration. System consists of 2
anti-afterburn valves, shutter solenoid valve, coasting/shutter
valve, throttle sensor, dashpot (manual transmission models) and
connecting hoses and wiring.

OPERATION

The No. 2 anti-afterburn valve (located below air cleaner)
is actuated by the shutter solenoid valve to supply additional air
from air cleaner to intake manifold at initial deceleration to
prevent afterburning of fuel. The coasting/shutter valve work
together to supply air (coasting valve) and fuel (shutter valve)
during deceleration to prevent backfiring.
TESTING
NO. 1 ANTI-AFTERBURN VALVE
1) Warm engine to normal operating temperature and ensure
engine operates smoothly at idle. Stop engine. Disconnect air
pump-to-air control hose at air pump.
2) Disconnect electrical connectors from relief solenoid
valve (Blue color dot) and switching solenoid valve (Gray color dot).
Start engine and run at idle. Place finger over air pump-to-air
control hose.
3) Air should not be drawn in and idle speed should not
change. Disconnect vacuum sensing tube "A". The idle speed should
drop and return to normal idle when tube is connected. If valve does
not respond as outlined, replace No. 1 anti-afterburn valve.
NOTE: Before replacing No. 1 anti-afterburn valve, check auxiliary
control unit as outlined in "Mazda RX7 Auxiliary Control
Device" article in this section. Also check relief solenoid
valve and switching solenoid valve as described in "Mazda
RX7 Air Injection System" article in this section.

DECELERATION CONTROL SYSTEM

Article Text
1983 Mazda RX7
For www.iluvmyrx7.com
Copyright © 1998 Mitchell Repair Information Company, LLC
Sunday, August 26, 2001 04:58PM