performance ............ A .. Require repair or replacement.
Fins damaged, not
affecting performance .. .. ........ No service suggested or
required.
Internal restrictions ... B .. Require repair or replacement.
Leaking ................. A .. Require repair or replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A .. Require repair or replacement.
Tubes damaged, affecting
performance ............ A .. Require repair or replacement.
Tubes damaged, not
affecting performance .. .. ........ No service suggested or
required.
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TRANSMISSION MOUNTS
See MOUNTS (ENGINE, TRANSAXLE AND TRANSMISSION) .
TRANSMISSION PANS
TRANSMISSION PAN INSPECTION \
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Condition Code Procedure
Bent, interfering with
filter or other internal
components ............. A .. Require repair or replacement.
Leaking ................. A .. Require repair or replacement.
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TRANSMISSION RANGE INDICATORS (PRNDL)
TRANSMISSION RANGE INDICATOR (PRNDL) INSPECTION \
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Condition Code Procedure
Binding ................. A .. Require repair or replacement.
Broken .................. A .. Require repair or replacement.
Components missing ...... C .. Require replacement of missing
components.
Loose, affecting
performance ............ A .. Require repair or replacement.
Out of adjustment ....... A ................. Require repair.
Worn, affecting
performance ............ A .. Require repair or replacement.
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TUBES
See HOSES, LINES AND TUBES .
UNIVERSAL JOINTS (CARDON OR CROSS TYPE)
UNIVERSAL JOINT (CARDON OR CROSS TYPE) INSPECTION \
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Condition Code Procedure
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
E - THEORY/OPERATION
1998 Mitsubishi Montero
1998 ENGINE PERFORMANCE
Mitsubishi - Theory & Operation
Diamante, Eclipse, Galant, Mirage, Montero, Montero Sport,
3000GT
INTRODUCTION
This article covers basic description and operation of engine
performance-related systems and components. Read this article before
diagnosing vehicles or systems with which you are not completely
familiar.
AIR INDUCTION SYSTEM
NON-TURBOCHARGED ENGINES
Mirage equipped with 1.5L engine uses a Manifold Absolute
Pressure (MAP) sensor instead of a Volume Airflow (VAF) sensor.
Filtered air is ducted to a plenum-mounted throttle body.
All other models use same basic air induction system using a
remote air filter (with VAF sensor) connected to a plenum-mounted
throttle body.
TURBOCHARGED ENGINES
In addition to basic air induction system, turbocharging
system components include turbocharger(s), charge air cooler(s), air\
by-pass valve(s), wastegate actuator(s), wastegate control solenoid
valve(s) and intake duct(s).
Wastegate Control Solenoid Valve(s)
Powertrain Control Module (PCM) energizes solenoid valve(s)\
,
controlling bleed-off rate of turbocharger pressure by wastegate
actuator(s).
COMPUTERIZED ENGINE CONTROLS
Sequential Fuel Injection (SFI) is a computerized engine
control system, which controls fuel injection, ignition timing, idle
speed and emission control systems.
POWERTRAIN CONTROL MODULE (PCM)
PCM, also known as Engine Control Module (ECM), receives and
processes signals from input devices. Operating conditions such as
cold starting, altitude, acceleration and deceleration affect input
device signals. Based on signals received, PCM sends signals to
various components, which control fuel injection, ignition timing,
idle speed and emission control systems. For PCM location, see
PCM LOCATION table.
PCM LOCATION TABLE
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Application Location
Eclipse 2.0L Non-Turbo .......... In Front of Left Front Strut Tower
usage on specific models, see appropriate wiring diagram in
L - WIRING DIAGRAMS article. For theory and operation on each
output component, refer to system indicated after component.
Data Link Connector (DLC)
See SELF-DIAGNOSTIC SYSTEM .
EGR Control Solenoid Valve
See EXHAUST GAS RECIRCULATION (EGR) CONTROL under EMISSION
SYSTEMS.
Fuel Injectors
See FUEL CONTROL under FUEL SYSTEM.
Fuel Pressure Control Solenoid Valve (Turbo)
See FUEL DELIVERY under FUEL SYSTEM.
Fuel Pressure Regulator
See FUEL DELIVERY under FUEL SYSTEM.
Idle Air Control (IAC) Motor
See IDLE SPEED under FUEL SYSTEM.
Malfunction Indicator Light
See SELF-DIAGNOSTIC SYSTEM .
Power Transistor(s) & Ignition Coils
See IGNITION SYSTEMS .
Purge Control Solenoid Valve
See EVAPORATIVE CONTROL under EMISSION SYSTEMS.
Wastegate Control Solenoid Valve
See TURBOCHARGED ENGINES under AIR INDUCTION SYSTEM.
FUEL SYSTEM
FUEL DELIVERY
Electric fuel pump, located in gas tank, feeds fuel through
in-tank fuel filter, external fuel filter (located in engine
compartment) and fuel injector rail.
Fuel Pump
Fuel pump consists of a motor-driven impeller. Pump has an
internal check valve to maintain system pressure, and a relief valve
to protect fuel pressure circuit. Pump receives voltage supply from
MFI control relay.
Fuel Pressure Control Solenoid Valve (Turbo)
Valve prevents rough idle due to fuel percolation. On engine
restart, if engine coolant or intake air temperature reaches a preset
value, PCM applies voltage to fuel pressure control solenoid valve for
2 minutes after enginerestart. Valve will open, allowing atmospheric
pressure to be applied to fuel pressure regulator diaphragm. This
allows maximum available fuel pressure at injectors, enriching fuel
mixture and maintaining stable idle at high engine temperatures.
Fuel Pressure Regulator
Located on fuel injector rail, this diaphragm-operated relief
valve adjusts fuel pressure according to engine manifold vacuum.
As engine manifold vacuum increases (closed throttle), fuel
inspection procedures.
A visual inspection is made to determine if any required
emission control devices are missing, modified or disconnected.
Missing, modified or disconnected systems must be made fully
operational before a vehicle can be certified.
POSITIVE CRANKCASE VENTILATION (PCV)
PCV controls the flow of crankcase fumes into the intake
manifold while preventing gases and flames from traveling in the
opposite direction. PCV is either an open or closed system. See Fig. 2
.
Ensure PCV system is installed as required. Verify valve,
required hoses, connections, flame arresters, etc., are present,
routed properly and in serviceable condition.
Fig. 2: Typical Open & Closed Type PCV System
THERMOSTATIC AIR CLEANER (TAC)
The TAC supplies warm air to air intake during cold engine
operation. This system is active during cold engine warm-up only.
Under all other operating conditions, air cleaner function is the same
as any non-thermostatic unit.
Ensure required exhaust shroud, hot air duct, vacuum hoses
and air cleaner components are present and installed properly. See
Fig. 3 . Ensure any required thermostatic vacuum switches are in place
and vacuum hoses are installed and in serviceable condition. Also
ensure air cleaner lid is installed right side up. Check for oversized
air filter elements and for additional holes in the air cleaner
housing.
Spark control systems are designed to ensure the air/fuel
mixture is ignited at the best possible moment to provide optimum
efficiency and power and cleaner emissions.
Ensure vacuum hoses to the distributor, carburetor, spark
delay valves, thermal vacuum switches, etc., are in place and routed
properly. On Computerized Engine Controls (CEC), check for presence of\
required sensors (O2, MAP, CTS, TPS, etc.). Ensure they have not been
tampered with or modified.
Check for visible modification or replacement of the feedback
carburetor, fuel injection unit or injector(s) with a non-feedback
carburetor or fuel injection system. Check for modified emission-
related components unacceptable for use on pollution-controlled
vehicles.
AIR INJECTION SYSTEM (AIS)
Air Pump Injection System (AP)
The air pump is a belt-driven vane type pump, mounted to
engine in combination with other accessories. The air pump itself
consists of the pump housing, an inner air cavity, a rotor and a vane
assembly. As the vanes turn in the housing, filtered air is drawn in
through the intake port and pushed out through the exhaust port. See
Fig. 13 .
Check for missing or disconnected belt, check valve(s),
diverter valve(s), air distribution manifolds, etc. Check air
injection system for proper hose routing.
Fig. 13: Typical Air Pump Injection System
Courtesy of General Motors Corp.
Pulsed Secondary Air Injection (PAIR) System
PAIR eliminates the need for an air pump and most of the
associated hardware. Most systems consists of air delivery pipe(s),
pulse valve(s) and check valve(s). The check valve prevents exhaust
gases from entering the air injection system. See Fig. 14.
Ensure required check valve(s), diverter valve(s), air
distribution manifolds, etc., are present. Check air injection system
for proper hose routing.
* ENGINE SYSTEMS UNIFORM INSPECTION GUIDELINES *
1998 Mitsubishi Montero
GENERAL INFORMATION
Engine Performance and Maintenance Motorist Assurance Program
Standards For Automotive Repair
All Makes and Models
INTRODUCTION TO MOTORIST ASSURANCE PROGRAM (MAP)
CONTENTS
Motorist Assurance Program (MAP)
OVERVIEW OF MOTORIST ASSURANCE PROGRAM
OVERVIEW OF SERVICE REQUIREMENTS AND SUGGESTIONS
Engine Assemblies
CYLINDER HEAD ASSEMBLIES
LONG BLOCK ASSEMBLIES
SHORT BLOCK ASSEMBLIES
Engine Components
ACCELERATOR PEDAL POSITION SENSORS
ACCESSORY BELTS
ACCESSORY PULLEYS
ACTUATORS
AIR CONDITIONING CYCLING SWITCHES
AIR CONDITIONING PRESSURE SENSORS
AIR DUCTS AND TUBES
AIR FILTER ELEMENTS
AIR FILTER GASKETS
AIR FILTER HOUSINGS AND GASKETS
AIR FUEL RATIO SENSORS
AIR INJECTION CONTROL SOLENOIDS
AIR PLENUMS
AIR PUMP BELTS
AIR PUMPS (ELECTRIC-DRIVEN)
AIR TUBES
ASPIRATOR, CHECK AND DECEL VALVES
BAFFLES
BALLAST PRIMARY SUPPLY RESISTOR WIRES
BALLAST RESISTORS AND PRIMARY SUPPLY RESISTOR WIRES
BAROMETRIC PRESSURE SENSORS
BATTERIES
BATTERY CABLES, WIRES AND CONNECTORS
BATTERY CONNECTORS
BATTERY TRAYS AND HOLD DOWN HARDWARE
BATTERY WIRES
BELT-DRIVEN AIR PUMPS
BELT IDLER ASSEMBLIES (ACCESSORY AND CAM BELTS)
BELT TENSIONERS (ACCESSORY AND CAM BELTS)
BOOST CONTROL MECHANISMS
CAMSHAFT POSITION SENSORS
CARBURETORS AND CHOKES
CASTING CORE PLUGS AND EXPANSION PLUGS
CHARGE AIR COOLERS "INTERCOOLERS" (CAC)
CHECK VALVES
CHOKES
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.
Leaking ................. A .. Require repair or replacement.
Missing ................. C ............ Require replacement.
Restricted, affecting
performance ............ A .. Require repair or replacement.
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AIR FILTER ELEMENTS
AIR FILTER ELEMENT INSPECTION \
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Condition Code Procedure
Leaking ................. A ............ Require replacement.
Paper filter element
oil-soaked ............ A ........ ( 1) Require replacement.
Maintenance intervals ... 3 ... Suggest replacement to comply
with vehicle's OEM recommended
service intervals.
Melted .................. A ........... Required replacement.
Missing ................. C ............ Require replacement.
Restricted, affecting
performance ............ A ............ Require replacement.
Water-contaminated ...... A ........ ( 1) Require replacement.
( 1) - Further inspection required to determine cause.
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AIR FILTER GASKETS
See AIR FILTER HOUSINGS AND GASKETS .
AIR FILTER HOUSINGS AND GASKETS
AIR FILTER HOUSING AND GASKET INSPECTION \
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Condition Code Procedure
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.
Leaking ................. A .. Require repair or replacement.
Missing ................. C ............ Require replacement.
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AIR FUEL RATIO SENSORS
(1) - Determine cause and correct prior to repair or
replacement of part.
( 2) - Determine source of contamination, such as engine
coolant, fuel, metal particles, or water. Require
repair or replacement.
( 3) - Inoperative includes intermittent operation or out of
OEM specification. Some components may be serviceable;
check for accepted cleaning procedure.
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ENGINE COOLING SYSTEMS
NOTE: Overheating, poor engine performance, and insufficient
cabin heat can be affected by, but are not limited to,
all of the components in the engine cooling system.
ENGINE COVERS (OIL PAN, VALVE COVER, TIMING COVER)
ENGINE COVER (OIL PAN, VALVE COVER, TIMING COVER) INSPECTION \
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Condition Code Procedure
Attaching hardware
incorrect .............. B ............ Require replacement.
Attaching hardware
loose .................. A .. Require repair or replacement.
Attaching hardware
missing ................ C ............ Require replacement.
Baffle loose ............ 2 .. Suggest repair or replacement.
Baffle missing .......... C ............ Require replacement.
Bent, affecting
performance ............ A .. Require repair or replacement.
Bent, not affecting
performance ............ .. ....... No service suggested or
required.
Cracked (not leaking) ... 2 .. Suggest repair or replacement.
Leaking externally ...... A .. Require repair or replacement.
Leaking internally,
causing fluid
contamination .......... A .. Require repair or replacement.
Missing ................. C ............ Require replacement.
Restricted passage ...... A .. Require repair or replacement.
Threads damaged ......... A .. Require repair or replacement.
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ENGINE OIL
ENGINE OIL INSPECTION \
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Condition Code Procedure
Contaminated ............ A .. ( 1) Require replacement of oil
and filter.
Level high .............. B ... Determine source of incorrect
level and require repair.
Level low ............... B ... Determine source of incorrect
level and require repair.
Maintenance intervals ... 3 ... Suggest replacement to comply
with vehicle's OEM recommended
service intervals.
( 1) - Determine source of contamination, such as engine coolant,
fuel, metal particles, or water when changing oil. Require