Jeep KJ 2005 Service Manual page 2376

KJ
EVAPORATIVE EMISSIONS
DESCRIPTION - EVAPORATION CONTROL
SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
SPECIFICATIONS
TORQUE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
EVAP/PURGE SOLENOID
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 14
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 14
FUEL FILLER CAP
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 14
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
ORVR
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 14
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
PUMP-NATURAL VAC LEAK DETECTION
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 15
EVAPORATIVE EMISSIONS
DESCRIPTION - EVAPORATION CONTROL
SYSTEM
The evaporation control system prevents the emis-
sion of fuel tank vapors into the atmosphere. When
fuel evaporates in the fuel tank, the vapors pass
through the control valve located in the top section of
the fuel pump module, through the fuel management
valve, and through vent hoses and tubes to a char-
coal filled evaporative canister. The canister tempo-
rarily holds the vapors. The Powertrain Control
Module (PCM) allows intake manifold vacuum to
draw vapors into the combustion chambers during
certain operating conditions.
EVAPORATIVE EMISSIONS
TABLE OF CONTENTS
page
EVAPORATIVE EMISSIONS
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 16
PCV VALVE
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 17
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
DIAGNOSIS AND TESTING - PCV VALVE
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 19
VACUUM LINES
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 20
VAPOR CANISTER
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 20
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 21
Gas powered engines use a duty cycle purge sys-
tem. The PCM controls vapor flow by operating the
duty cycle EVAP purge solenoid. Refer to Duty Cycle
EVAP Canister Purge Solenoid.
When equipped with certain emissions packages, a
Leak Detection Pump (LDP) will be used as part of
the evaporative system for OBD II requirements.
Also refer to Leak Detection Pump.
Vehicles powered with gasoline engines are also
equipped with ORVR (On-Board Refueling Vapor
Recovery). Refer to ORVR for additional information.
NOTE: The evaporative system uses specially man-
ufactured lines/hoses. If replacement becomes nec-
essary, only use fuel resistant, low permeation
hose.
Certain components can be found in (Fig. 1).
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