Chrysler Voyager 2000 GS, Инструкция

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EXHAUST GAS RECIRCULATION (EGR) SYSTEM
TABLE OF CONTENTS
page page
DESCRIPTION AND OPERATION
EXHAUST GAS RECIRCULATION . . . . . . . . . . . . 27
REMOVAL AND INSTALLATION
EGR VALVE SERVICE—3.0L ENGINES . . . . . . . . 28
EGR VALVE SERVICE—3.3/3.8L ENGINES . . . . . 29
EGR TUBE SERVICE—3.0L ENGINES . . . . . . . . . 29
EGR TUBE SERVICE—3.3/3.8L ENGINES . . . . . . 29
SPECIAL TOOLS
EMISSION CONTROL SYSTEM . . . . . . . . . . . . . . 30
DESCRIPTION AND OPERATION
EXHAUST GAS RECIRCULATION
DESCRIPTION
The EGR system consists of:
•
EGR tube (connects a passage in the intake
manifold to the exhaust manifold)
•
EGR valve
•
Electronic EGR Transducer
•
Connecting hoses
OPERATION
Refer to Monitored Systems - EGR Monitor in this
group for more information.
The engines use Exhaust Gas Recirculation (EGR)
systems (Fig. 1), (Fig. 2) and (Fig. 3). The EGR sys-
tem reduces oxides of nitrogen (NOx) in engine
exhaust and helps prevent detonation (engine knock).
Under normal operating conditions, engine cylinder
temperature can reach more than 3000°F. Formation
of NOx increases proportionally with combustion
temperature. To reduce the emission of these oxides,
the cylinder temperature must be lowered. The sys-
tem allows a predetermined amount of hot exhaust
gas to recirculate and dilute the incoming air/fuel
mixture. The diluted air/fuel mixture reduces peak
flame temperature during combustion.
The electric EGR transducer contains an electri-
cally operated solenoid and a back-pressure trans-
ducer (Fig. 4). The Powertrain Control Module (PCM)
operates the solenoid. The PCM determines when to
energize the solenoid. Exhaust system back-pressure
controls the transducer.
When the PCM energizes the solenoid, vacuum
does not reach the transducer. Vacuum flows to the
transducer when the PCM de-energizes the solenoid.
When exhaust system back-pressure becomes high
enough, it fully closes a bleed valve in the trans-
ducer. When the PCM de-energizes the solenoid and
back-pressure closes the transducer bleed valve, vac-
Fig. 1 EGR Mounting—2.4L Engine
1 – EGR SOLENOID AND TRANSDUCER
2 – EGR VALVE
3 – EGR TUBE
Fig. 2 EGR Mounting—3.0L Engine
1 – EGR SOLENOID
2 – EGR VALVE
3 – EGR TUBE
4 – TRANSDUCER
NS
EMISSION CONTROL SYSTEMS 25 - 27