evap MITSUBISHI MONTERO 1998 Owner's Manual
Page 460 of 1501
cylinder is on its exhaust stroke when plug fires.
HALL EFFECT IGNITION SYSTEM
This system is equipped with a Hall Effect distributor.
Shutter(s) attached to distributor shaft rotate through distributor
Hall Effect switch, also referred to as a Camshaft Position (CMP)
sensor, which contains a distributor pick-up (a Hall Effect device and
magnet). As shutter blade(s) pass through pick-up, magnetic field is
interrupted and voltage is toggled between high and low. PCM uses this
data along with Crankshaft Position (CKP) sensor data to control
ignition timing and injector pulse width to maintain optimum
driveability.
Power Transistor & Ignition Coil
Power transistor is mounted inside distributor with disc and
optical sensing unit. When ignition is on, ignition coil primary
circuit is energized. As distributor shaft rotates, disc rotates,
triggering optical sensing unit. PCM receives signals from optical
sensing unit. Signals are converted and sent to power transistor,
interrupting primary current flow and inducing secondary voltage.
IGNITION TIMING CONTROL SYSTEM
Ignition timing is controlled by PCM. PCM adjusts timing
based on various conditions such as engine temperature, altitude and
detonation.
EMISSION SYSTEMS
EXHAUST GAS RECIRCULATION (EGR) CONTROL
Federal Emissions (Non-Turbo)
To lower oxides of nitrogen (NOx) exhaust emissions, a non-
computer controlled exhaust gas recirculation system is used. EGR
operation is controlled by throttle body ported vacuum. Vacuum is
routed through vacuum control valve to prevent EGR operation at low
engine temperatures.
Spring pressure holds EGR valve closed during low vacuum
conditions (engine idling or wide open throttle). When vacuum pressure\
increases and overcomes EGR spring pressure, EGR valve is lifted to
allow exhaust gases to flow into intake manifold for combustion.
California Emissions & Turbo
PCM controls EGR operation by activating EGR control solenoid
valve according to engine load. When engine is cold, PCM signals EGR
control solenoid valve to deactivate EGR.
EGR Control Solenoid Valve
Valve denies or allows vacuum supply to EGR valve based on
PCM commands.
EVAPORATIVE CONTROL
Fuel evaporation system prevents fuel vapor from entering
atmosphere. System consists of special fuel tank with vapor separator
tanks (if equipped), vacuum relief filler cap, overfill limiter (2-wa\
y
valve), fuel check valve, thermovalve (if equipped), charcoal
canister, purge control valve, purge control solenoid valve, and
connecting lines and hoses.
Purge Control Solenoid Valve
Page 469 of 1501
Junction Block Behind left side of dash.
Passenger Compartment Relay Box Behind left side of dash.
Power Seat Relay Box Under driver's seat.
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CONTROL UNITS
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Component Component Location \
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ABS Control Unit Mounted on top of right rear
wheelwell, under metal plate.
A/C Control Unit On top of evaporator case.
Antenna Motor ECU Behind center console.
Auto-Cruise Control ECU Behind center of dash.
Page 471 of 1501
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Component Component Location \
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ABS Speed Sensors (4) On bracket, on each wheel hub.\
Air Inlet Sensor In evaporator air duct.
Camshaft Position Sensor At bottom of left camshaft
gear.
Crankshaft Position Sensor Above crankshaft gear.
Engine Coolant Temperature Gauge Unit On thermostat housing.
Engine Coolant Temperature Sensor On thermostat housing.
Front Impact Sensor (Left) (SRS) On left front of engine
compartment.
Front Impact Sensor (Right) (SRS) On right front of engine
compartment.
Fuel Gauge Unit In fuel tank.
Fuel Tank Differential Pressure Sensor
(Calif.) Top of fuel tank.
G-Sensor (ABS) In center console, rear of
parking brake lever.
Geomagnetic Sensor (Compass) On top center of dash.
Page 472 of 1501
Heated Oxygen Sensor (Front)
(Federal) Underside of vehicle, forward
of catalytic converter.
Heated Oxygen Sensor (Front)
(Left Bank) (Calif.) In left exhaust manifold.
Heated Oxygen Sensor (Front)
(Right Bank) (Calif.) In right exhaust manifold.
Heated Oxygen Sensor (Rear)
(Federal) Underside of vehicle, behind
catalytic converter.
Heated Oxygen Sensor (Rear) (Left Bank)
(Calif.) In left exhaust pipe, below
engine.
Heated Oxygen Sensor (Rear) (Right Bank)
(Calif.) In right exhaust pipe, below
engine.
Input Shaft Speed Sensor On side of transmission.
Intake Air Temperature Sensor Mounted on outside of
evaporator case.
Manifold Differential Pressure Sensor On top left rear of engine.
Output Shaft Speed Sensor On rear of transmission.
Page 473 of 1501
Outside Air Temperature Sensor Below left headlamp.
Park/Neutral Position Sensor On left side of transmission.
Throttle Position Sensor On throttle body.
Vehicle Speed Sensor (VSS) On transmission tailshaft.
Volume Airflow Sensor In air cleaner duct (includes
intake air temperature sensor
& barometric pressure sensor).
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SOLENOIDS & SOLENOID VALVES
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Component Component Location \
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ABS Hydraulic Unit (w/Built-In
Solenoid Valve) In right rear corner of engine
compartment.
Cruise Control Actuator (w/Built-In
Control Valve & Release Valve)
(Calif.) In right rear of engine
compartment.
Cruise Control Actuator (w/Built-In
Control Valve & Release Valve)
(Federal) In left rear of engine
compartment.
EGR Solenoid In right rear of engine
compartment.
ELC 4-Speed Automatic Transmission
Control Solenoid Inside transmission.
Evaporative Emission Purge Solenoid On front of engine.
Evaporative Emission Ventilation
Solenoid In left rear of engine
compartment.
Solenoid Valves "A" & "B" In right side of engine
compartment.
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SWITCHES
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Component Component Location \
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A/T Fluid Temperature Switch On left side of transmission.
Brake Fluid Level Switch In brake master cylinder
reservoir.
Center Differential Lock Detection
Switch On transfer case.
Page 535 of 1501
Fig. 3: Typical Thermostatic Air Cleaner System
FUEL EVAPORATIVE SYSTEM (EVAP)
The EVAP system allows for proper fuel system ventilation
while preventing fuel vapors from reaching the atmosphere. This means
that vapors must be caught and stored while the engine is off, which
is when most fuel evaporation occurs. When the engine is started,
these fuel vapors can be removed from storage and burned. In most
systems, storage is provided by an activated charcoal (or carbon)
canister. See Fig. 4. On a few early systems, charcoal canisters are
not used. Instead, fuel vapors are vented into the PCV system and
stored inside the crankcase.
The main components of a fuel evaporation system are a sealed
fuel tank, a liquid-vapor separator and vent lines to a vapor-storing
canister filled with activated charcoal. The filler cap is normally
not vented to the atmosphere, but is fitted with a valve to allow both
pressure and vacuum relief.
Although a few variations do exist between manufacturers,
basic operation is the same for all systems. Check for presence of
vapor storage canister or crankcase storage connections when required.
Ensure required hoses, solenoids, etc., are present and connected
properly. Check for proper type fuel tank cap. Check for any non-OEM
or auxiliary fuel tanks for compliance and the required number of
evaporation canisters.
Page 536 of 1501
Fig. 4: Typical Fuel Evaporative System
CATALYTIC CONVERTERS
Oxidation Catalyst (OC)
This type of converter is the most common. It may use pellets
or monolith medium, depending upon application. See Fig. 5. Platinum
and palladium (or platinum alone) are used as catalyst in this type of\
converter.
Visually check for presence of catalytic converter(s). Check
for external damage such as severe dents, removed or damaged heat
shields, etc. Also check for pellets or pieces of converter in the
tailpipe.
Fig. 5: Typical Oxidation Catalytic Converter (Pellet Type) Shown;
Typical Three-Way Catalytic Converter Is Similar
Courtesy of General Motors Corp.
Three-Way Catalyst (TWC)
This type of converter is nearly identical to a conventional
Page 546 of 1501
EARLY FUEL EVAPORATION (EFE)
The EFE valve is actuated by either a vacuum actuator or a
bimetal spring (heat-riser type). The EFE valve is closed when engine
is cold. The closed valve restricts exhaust gas flow from the exhaust
manifold. This forces part of the exhaust gas to flow up through a
passage below the carburetor. As the exhaust gas quickly warms the
intake mixture, distribution is improved. This results in better cold
engine driveability, shorter choke periods and lower emissions.
Ensure EFE valve in exhaust manifold is not frozen or rusted
in a fixed position. On vacuum-actuated EFE system, check EFE thermal
vacuum valve and check valve(s). Also check for proper vacuum hose
routing. See Fig. 15.
Fig. 15: Typical Vacuum-Actuated EFE System
Courtesy of General Motors Corp.
EMISSION MAINTENANCE REMINDER LIGHT (EMR) (IF EQUIPPED)
Page 589 of 1501
CLUTCH PEDAL POSITION SWITCHES
COLD START INJECTORS
CONNECTORS
COOLANT
COOLANT RECOVERY TANKS
COOLING FAN MOTOR MODULES
COOLING FAN MOTOR RELAYS AND MODULES
COOLING FAN MOTOR RESISTORS
COOLING FAN MOTOR SENSORS AND SWITCHES
COOLING FAN MOTOR SWITCHES
COOLING FAN MOTORS
CRANKSHAFT POSITION SENSORS
DECEL VALVES
DEFLECTORS
DIP STICKS AND TUBES
DIP STICK TUBES
DISTRIBUTOR ADVANCES AND RETARDERS (MECHANICAL AND VACUUM)
DISTRIBUTOR BOOTS AND SHIELDS
DISTRIBUTOR CAPS
DISTRIBUTOR RETARDERS (MECHANICAL AND VACUUM)
DISTRIBUTOR ROTORS
DISTRIBUTOR SHIELDS
DISTRIBUTORS
EARLY FUEL EVAPORATION VALVES (HEAT RISER ASSEMBLIES)
EGR COOLERS
EGR EXHAUST MANIFOLD PASSAGES
EGR INTAKE AND EXHAUST MANIFOLD PASSAGES
EGR PLATES AND COOLERS
ELECTRONIC SPARK CONTROL MODULES
ELECTRONIC TRANSMISSION CONTROL DEVICES
ELECTRONIC TRANSMISSION FEEDBACK DEVICES
ENGINE COOLANT TEMPERATURE SENSORS
ENGINE COOLING SYSTEMS
ENGINE COVERS (OIL PAN, VALVE COVER, TIMING COVER)
ENGINE OIL
ENGINE OIL CANISTERS
ENGINE OIL COOLERS (EXTERNAL)
ENGINE OIL DRAIN PLUGS AND GASKETS
ENGINE OIL FILTERS AND CANISTERS
ENGINE OIL GASKETS
ENGINE OIL PRESSURE GAUGES (MECHANICAL)
EVAPORATIVE EMISSION (EVAP) CANISTER FILTERS
EVAPORATIVE EMISSION (EVAP) CANISTER PURGE DEVICES
EVAPORATIVE EMISSION (EVAP) CANISTERS
EVAPORATIVE EMISSION (EVAP) FEEDBACK DEVICES
EXHAUST GAS RECIRCULATION DEVICES
EXHAUST GAS RECIRCULATION FEEDBACK DEVICES
EXPANSION PLUGS
FAN CONTROL SENSORS
FUEL
FUEL ACCUMULATORS AND DAMPERS
FUEL AND COLD START INJECTORS
FUEL DAMPERS
FUEL DELIVERY CHECK VALVES
FUEL DISTRIBUTORS (BOSCH CIS)
FUEL FILLER NECKS AND RESTRICTORS
FUEL FILTERS
FUEL INJECTORS
FUEL LEVEL SENDERS7
FUEL PRESSURE REGULATORS
FUEL PUMPS (IN-TANK AND EXTERNAL, ELECTRICAL OR MECHANICAL)
FUEL RAILS
FUEL RESTRICTORS
Page 624 of 1501
Thrust washer missing ... C .. Require repair or replacement.
Thrust washer worn,
affecting performance .. A .. Require repair or replacement.
Thrust washer worn, not
affecting performance .. 1 .. Suggest repair or replacement.
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EARLY FUEL EVAPORATION VALVES (HEAT RISER ASSEMBLIES)
EARLY FUEL EVAPORATION VALVE (HEAT RISER ASSEMBLY) INSPECTION \
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Condition Code Procedure
Broken .................. A . Require replacement of affected
parts.
Diaphragm inoperative ... A .......... ( 1) Further inspection
required.
Leaking ................. A .. Require repair or replacement.
Noisy ................... 2 .. Suggest repair or replacement.
Seized .................. A . Require replacement of affected
parts.
Spring broken ........... B .......... Require replacement of
spring(s).
Spring inoperative ...... A ...... ( 2) Require replacement of
spring(s).
( 1) - Inoperative includes intermittent operation or out of
OEM specification. If the inoperative diaphragm is
separate from the heat riser, then require replacement
of the inoperative diaphragm. If the inoperative
diaphragm is part of the heat riser, then replace the
heat riser.
( 2) - Inoperative includes intermittent operation or out of OEM
specification.
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EGR COOLERS
See EGR PLATES AND COOLERS .
EGR EXHAUST MANIFOLD PASSAGES
See EGR INTAKE AND EXHAUST MANIFOLD PASSAGES .
EGR INTAKE AND EXHAUST MANIFOLD PASSAGES
EGR INTAKE AND EXHAUST MANIFOLD PASSAGE INSPECTION \
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Condition Code Procedure
Leaking ................. A .. Require repair or replacement.
Restricted, affecting
performance ............ A .. Require repair or replacement.
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EGR PLATES AND COOLERS
EGR PLATE AND COOLER INSPECTION \
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Condition Code Procedure
Leaking ................. A .. Require repair or replacement.