fuel MITSUBISHI MONTERO 1998 Service Manual

specified, replace solenoid. If solenoid tests as specified, go to
next step.
4) Ensure solenoid holds vacuum with nipple "B" unplugged,
and negative jumper wire connected. If solenoid does not test as
specified, replace solenoid. If solenoid tests as specified, go to
next step.
5) Check resistance between solenoid terminals. If resistance
is not 36-44 ohms at 68
F (20C), replace solenoid. If resistance is
as specified, go to step 7).
6) Turn ignition switch to ON position. Using scan tool, turn
fuel pressure solenoid on and off (item 09). Clicking sound should be
heard. If clicking sound is heard, go to step 9). If clicking sound is
not heard, go to next step.
7) Disconnect fuel pressure solenoid connector. Using DVOM,
check for voltage between chassis ground and fuel pressure solenoid
terminal No. 1. If battery voltage does not exist, repair wiring
harness as necessary. If battery voltage exists, go to next step.
8) Turn ignition switch to OFF position. Disconnect PCM
connector. Ground PCM connector terminal No. 48. Check continuity
between chassis ground and fuel pressure solenoid connector terminal
No. 2. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, go to next step.
9) Test is complete. Intermittent problem may exist. Road
test vehicle (if necessary) and attempt to duplicate conditions that
caused original complaint. Recheck for DTCs. If no DTCs are displayed,
go to INTERMITTENT DTCS .
DTC P1400: MANIFOLD DIFFERENTIAL PRESSURE (MDP) SENSOR
CIRCUIT FAILURE
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
1) Component testing procedure without using scan tool not
available from manufacturer at time of publication. Warm vehicle to
normal operating temperature and allow engine to idle. Go to next
step.
2) Using scan tool, read intake manifold pressure (item 95).\
See INTAKE MANIFOLD PRESSURE SPECIFICATIONS table. If scan tool does
not read as specified, replace MDP sensor. If scan tool reads as
specified, go to next step.
INTAKE MANIFOLD PRESSURE SPECIFICATIONS TABLE









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Application psi (kPa)
Montero .............................. 3.0-4.9 (20.6-34.0)
3000GT
DOHC
Non-Turbo ........................ 3.7-5.7 (25.5-38.9)
Turbo ............................ 4.2-6.2 (29.0-42.4)
SOHC ............................... 3.9-5.8 (26.5-39.9)









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3) Disconnect MDP sensor connector. Using DVOM, check
continuity between chassis ground and MDP sensor connector terminal
No. 2. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, go to next step.
4) Turn ignition switch to OFF position. With MDP sensor
connector disconnected, disconnect PCM connector. Ground PCM connector
terminal No. 92. Check continuity between chassis ground and MDP
sensor connector terminal No. 1. If continuity does not exist, repair

H - TESTS W/O CODES
1998 Mitsubishi Montero
1998 ENGINE PERFORMANCE
Mitsubishi - Trouble Shooting - No Codes
Diamante, Eclipse, Galant, Mirage, Montero, Montero Sport,
3000GT
INTRODUCTION
Before using this article to diagnose symptoms or
intermittent faults, perform testing in F - BASIC TESTING article and
G - TESTS W/CODES article. Use this article to diagnose driveability
problems existing when a hard Diagnostic Trouble Code (DTC) is not
present.
NOTE: Some driveability problems may have been corrected by
manufacturer with a revised Powertrain Control Module (PCM).
Check with manufacturer for latest PCM.
Symptom checks can direct technician to malfunctioning
component(s) for further diagnosis. A symptom should lead to a
specific component, system test or adjustment.
Use intermittent test procedures to locate driveability
problems that DO NOT occur when vehicle is being tested. These test
procedures should also be used if an intermittent DTC was present, but
no problem was found during self-diagnostic testing.
NOTE: For specific testing procedures, see G - TESTS W/CODES
article. For specifications, see D - ADJUSTMENTS or
C - SPECIFICATIONS article.
SYMPTOMS
SYMPTOM DIAGNOSIS
Symptom checks cannot be used unless problem occurs while
vehicle is being tested. Before using this article to diagnose any
symptom, perform basic diagnostic procedures in F - BASIC TESTING
article and self-diagnostics in G - TESTS W/CODES article in order to
reduce diagnostic time. The following symptoms are available for
diagnosis:
* Difficult To Start/No Start (Cranks Okay)
* Rough Or Unstable Idle
* Engine Hesitates Or Poor Acceleration
* Engine Surges
* Detonation Or Knocking
* Poor Fuel Mileage
DIFFICULT TO START/NO START (CRANKS OKAY)
* Check idle air control (DC) motor (if applicable).
* Check idle air control (stepper) motor (if applicable).
* Check ignition switch.
* Check camshaft position sensor.
* Check crankshaft position sensor.
* Check park/neutral position switch (A/T).
* Check volume airflow sensor.
* Check engine coolant temperature sensor.

* Check power supply to PCM.
* Check fuel pressure.
* Check ignition timing.
* Check for disconnected or damaged vacuum hoses.
* Check for control relay malfunction.
* Check for SFI system malfunction.
* Check for fuel pump drive control system malfunction.
* Check for ignition coil malfunction.
* Check for power transistor malfunction (if applicable).
* Check for fuel injector malfunction.
* Check for PCM malfunction.
* Ensure electrical harness, connectors and wires are not
broken, bent or loose.
ROUGH OR UNSTABLE IDLE
* Check intake air temperature sensor.
* Check EVAP purge control solenoid valve (if applicable).
* Check vehicle speed sensor.
* Check engine coolant temperature sensor.
* Check barometric pressure sensor (if applicable).
* Check manifold absolute pressure sensor (if applicable).
* Check ignition switch.
* Check throttle position sensor.
* Check camshaft position sensor.
* Check crankshaft position sensor.
* Check power steering oil pressure switch (if applicable).
* Check A/C switch and power relay (if applicable).
* Check park/neutral position switch (A/T).
* Check heated oxygen sensor.
* Check volume airflow sensor.
* Check fuel pressure.
* Check for disconnected or damaged vacuum hoses.
* Check for SFI system malfunction.
* Check idle air control (DC) motor (if applicable).
* Check idle air control (stepper) motor (if applicable).
* Check for fuel injector malfunction.
* Check for power transistor malfunction (if applicable).
* Check for vehicle speed sensor malfunction.
* Check for PCM malfunction.
* Ensure electrical harness, connectors and wires are not
broken, bent or loose.
ENGINE HESITATES OR POOR ACCELERATION
* Check intake air temperature sensor.
* Check engine coolant temperature sensor.
* Check barometric pressure sensor (if applicable).
* Check manifold absolute pressure sensor (if applicable).
* Check ignition switch.
* Check ignition coil.
* Check EGR control solenoid valve (if applicable).
* Check throttle position sensor.
* Check camshaft position sensor.
* Check crankshaft position sensor.
* Check power steering oil pressure switch (if applicable).
* Check A/C switch and power relay (if applicable).
* Check park/neutral position switch (A/T).
* Check heated oxygen sensor.
* Check volume airflow sensor.
* Check fuel pressure.
* Check for disconnected or damaged vacuum hoses.
* Check for SFI system malfunction.

* Check idle air control (DC) motor (if applicable).
* Check idle air control (stepper) motor (if applicable).
* Check for fuel injector malfunction.
* Check for power transistor malfunction (if applicable).
* Check A/C switch and power relay (if applicable).
* Check for PCM malfunction.
* Ensure electrical harness, connectors and wires are not
broken, bent or loose.
ENGINE SURGES
* Check engine coolant temperature sensor.
* Check EGR control solenoid valve (if applicable).
* Check fuel pressure.
* Check for fuel injector malfunction.
DETONATION OR KNOCKING
* Check for knock sensor malfunction (if applicable).
* Check volume airflow sensor.
* Check for engine cooling system problems.
* Check fuel quality.
* Check intake air temperature sensor.
* Check barometric pressure sensor (if applicable).
* Check manifold absolute pressure sensor (if applicable).
* Check ignition coil.
* Check power transistor (if applicable).
* Check for EGR system malfunction.
POOR FUEL MILEAGE
* Check intake air temperature sensor.
* Check engine coolant temperature sensor.
* Check barometric pressure sensor (if applicable).
* Check manifold absolute pressure sensor (if applicable).
* Check ignition switch.
* Check throttle position sensor.
* Check camshaft position sensor.
* Check crankshaft position sensor.
* Check power steering oil pressure switch (if applicable).
* Check A/C switch and power relay (if applicable).
* Check park/neutral position switch (A/T).
* Check heated oxygen sensor.
* Check volume airflow sensor.
* Check fuel pressure.
* Check for SFI system malfunction.
* Check idle air control (DC) motor (if applicable).
* Check idle air control (stepper) motor (if applicable).
* Check for fuel injector malfunction.
* Check for power transistor malfunction (if applicable).
INTERMITTENTS
INTERMITTENT PROBLEM DIAGNOSIS
Intermittent fault testing requires duplicating circuit or
component failure to identify problem. These procedures may lead to
computer setting a Diagnostic Trouble Code (DTC) which may help in
diagnosis.
If problem vehicle does not produce DTCs, monitor voltage or
resistance values using a DVOM while attempting to reproduce
conditions causing intermittent fault. A status change on DVOM

* PLEASE READ THIS FIRST *
WARNING: To avoid injury from accidental air bag deployment, read and
carefully follow all SERVICE PRECAUTIONS and DISABLING &
ACTIVATING AIR BAG SYSTEM procedures in AIR BAG RESTRAINT
SYSTEM article.
CAUTION: When removing or installing floor console, DO NOT allow any
impact or shock to Supplemental Restraint System Electronic
Control Unit (SRS-ECU).
FRONT HEATER UNIT & HEATER CORE
Removal
1) Deactivate air bag system. See AIR BAG RESTRAINT SYSTEM
article. Remove front and rear floor consoles. Remove hood release
handle. Remove fuel door release handle. Remove knee protector and
support brackets. Remove speaker covers.
NOTE: On A/T models, when removing front floor console, set A/T
selector lever in "L" position.
2) Remove glove box door stop, glove box and glove box frame.
Remove passenger-side air bag module. Remove heater control panel
cover. Remove heater control panel and radio. Remove plug from
instrument cluster cover. Remove instrument cluster cover and
instrument cluster.
3) Remove steering column cover. Remove clock or plug. Remove
side defroster covers. Remove side mirror control switch. Remove front
speakers.
4) Remove rheostat, rear wiper/washer switch, and door lock
switch. Disconnect ventilation control cable and harness connector.
See Fig. 9. Remove instrument panel. See INSTRUMENT PANEL. Drain
coolant and disconnect heater hoses from heater unit.
5) Remove shower ducts, lap duct, joint duct and center duct.
See Fig. 1 . Remove center reinforcement. Remove heater unit. Remove
distribution duct. Remove heater core.
Installation
Install heater core, distribution duct, heater unit and
center reinforcement. Install remaining ducts in reverse order of
removal. Install instrument panel. Tighten steering column bolts to 16
ft. lbs. (22 N.m). Install and adjust ventilation control cable. See
ADJUSTMENTS . To complete installation, reverse removal procedure. Add
coolant and check for leaks.
INSTRUMENT PANEL
Removal & Installation
Remove instrument panel components and then instrument panel,
in order listed on appropriate illustration. See Fig. 9. To install,
reverse removal procedures.

Brake On/Off (BOO) Switch ................... Cruise Control Systems\
Engine Performance
Shift Interlock Systems
Buzzer Module ...................................... Warning Systems
Camshaft Position (CMP) Sensor .................. Engine Performance\
Central Control Module ........................... Anti-Theft System
Clockspring ............................... Air Bag Restraint System
Cruise Control Systems
Steering Column Switches
Clutch Pedal Position Switch .............................. Starters
Clutch Start Switch ....................................... Starters
Combination Meter ......................... Analog Instrument Panels
Constant Control Relay Module (CCRM) ............ Engine Performance\
Electric Cooling Fans
Convenience Center .............................. Power Distribution
Illumination/Interior Lights
Convertible Top Motor ........................ Power Convertible Top
Convertible Top Switch ....................... Power Convertible Top
Crankshaft Position (CKP) Sensor ................ Engine Performance\
Cruise Control Module ....................... Cruise Control Systems
Cruise Control Switch ....................... Cruise Control Systems
Condenser Fan Relay(s) ....................... Electric Cooling Fans\
Data Link Connector (DLC) ....................... Engine Performance\
Daytime Running Lights Module ............... Daytime Running Lights
Exterior Lights
Defogger Relay ................................ Rear Window Defogger
Diagnostic Energy Reserve Module (DERM) ... Air Bag Restraint System\
Discriminating Sensor (Air Bag) ........... Air Bag Restraint System\
Distributor ..................................... Engine Performance
Door Lock Actuators ............................... Power Door Locks
Remote Keyless Entry
Door Lock Relay(s) ................................ Power Door Locks\
Electrochromic Mirror ................................ Power Mirrors
Electronic Level Control (ELC)
Height Sensor .............................. Electronic Suspension
Electronic Level Control (ELC) Module ........ Electronic Suspension\
Engine Coolant Temperature (ECT)
Sending Unit ............................ Analog Instrument Panels
Engine Coolant Temperature (ECT) Sensor ......... Engine Performance\
Engine Control Module ........................... Engine Performance
Generators & Regulators
Starters
ETACS ECU .......................................... Warning Systems
Power Windows
Remote Keyless Entry
Evaporative (EVAP) Emissions Canister ........... Engine Performance\
EVAP Canister Purge Solenoid .................... Engine Performance
EVAP Canister Vent Solenoid ..................... Engine Performance
Exhaust Gas Recirculation (EGR) Valve ........... Engine Performance\
Fuel Tank Vacuum Sensor ......................... Engine Performance
Fog Lights ....................................... Headlight Systems
Daytime Running Lights
Fog Light Relay .................................. Headlight Systems
Daytime Running Lights
Fuel Door Release Solenoid ................. Power Fuel Door Release
Fuel Gauge Sending Unit ................... Analog Instrument Panels
Fuel Injectors .................................. Engine Performance
Fuel Pump ....................................... Engine Performance
Fuel Pump Relay ................................. Engine Performance
Power Distribution
Fuse/Relay Block ................................ Power Distribution
Fusible Links ................................... Power Distribution
Generators & Regulators

Starters
Generator .................................. Generators & Regulators
Engine Performance
Power Distribution
Generic Electronic Module (GEM) ............... Body Control Modules\
Electronic Suspension
Glow Plug Relay ................................. Engine Performance
Glow Plugs ...................................... Engine Performance
Grounds ........................................ Ground Distribution
Headlight Door Module .............................. Headlight Doors
Headlight Relay .................................. Headlight Systems
Daytime Running Lights
Headlights ....................................... Headlight Systems
Daytime Running Lights
Heated Oxygen Sensor(s) (HO2S) .................. Engine Performan\
ce
Heated Windshield Control Module ................ Heated Windshields
Height Sensor ................................ Electronic Suspension
Horns ..................................... Steering Column Switches
Horn Relay ................................ Steering Column Switches
Idle Air Control (IAC) Motor/Valve .............. Engine Performance\
Ignition Coil(s) ................................ Engine Performance\
Ignition Key Lock Cylinder ....................... Anti-Theft System
Ignition Module ................................. Engine Performance
Ignition Switch ................................. Power Distribution
Engine Performance
Generators & Regulators
Starters
Illuminated Entry Module .............. Illumination/Interior Lights
Illumination Lights ................... Illumination/Interior Lights
Impact Sensor ............................. Air Bag Restraint System
Inertia Fuel Shutoff Switch ..................... Engine Performance
Inhibit Relay ............................................. Starters
Instrument Cluster ........................ Analog Instrument Panels
Intake Air Temperature (IAT) Sensor ............. Engine Performance\
Interior Lights ....................... Illumination/Interior Lights
Interlock Switch .......................................... Starters
Junction Block .................................. Power Distribution
Keyless Entry Receiver ........................ Remote Keyless Entry
Key Reminder Switch ....................................... Starters
Knock Sensor .................................... Engine Performance
Lamp Control Module ................................ Exterior Lights
License Plate Lamp ................................. Exterior Lights
Lighting Control Module ................... Lighting Control Modules
Anti-Theft System
Daytime Running Lights
Headlight Systems
Lower Relay .................................. Power Convertible Top
Malfunction Indicator Light (MIL) ............... Engine Performance\
Instrument Panels
Manifold Absolute Pressure (MAP) Sensor ......... Engine Performance\
Mass Airflow (MAF) Sensor ....................... Engine Performance\
Mega Fuse .................................. Generators & Regulators
Memory Seat/Mirror Module ........................... Memory Systems
Mirror Defogger ............................... Rear Window Defogger
Moon Roof Motor .................................... Power Moon Roof
Moon Roof Relay .................................... Power Moon Roof
Multi-Function Control Module ...................... Warning Systems
Neutral Safety Switch ..................................... Starters
Oil Level Switch ................................ Engine Performance
Oil Pressure Switch/Sending Unit .......... Analog Instrument Panels
Engine Performance
Overhead Console .................................. Overhead Console
Oxygen Sensor(s) (O2S) .......................... Engine Performan\
ce

Torque Converter Clutch Solenoid/Switch ......... Engine Performance
Traction Control Switch ........................... Anti-Lock Brakes
Trailer Tow Connector .............................. Exterior Lights
Trailer Tow Relay .................................. Exterior Lights
Transmission/Transaxle .......................... Engine Performance
Transmission Control Module (TCM) ............... Engine Performance\
Starters
Transmission Range Sensor ................................. Starters
Back-Up Lights
Engine Performance
Transmission Range Switch ........................... Back-Up Lights
Engine Performance
Anti-Theft System
Turn Signal Flasher ................................ Exterior Lights
Turn Signal Lights ................................. Exterior Lights
Twilight Sentinel Switch ......................... Headlight Systems
Daytime Running Lights
Vapor Canister Leak Detection Pump .............. Engine Performance
Vehicle Control Module (VCM) .................... Engine Performance\
Vehicle Dynamic Module ....................... Electronic Suspension
Vehicle Speed Control Servo ................. Cruise Control Systems
Vehicle Speed Sensor .......................... Data Link Connectors
Analog Instrument Panels
Cruise Control Systems
Electronic Suspension
Voltage Regulator .......................... Generators & Regulators
Water-In-Fuel Sensor ............................ Engine Performance
Analog Instrument Panels
Wheel Speed Sensors ............................... Anti-Lock Brakes
Window Timer Module .......................... Power Convertible Top
Windshield Intermittent Wiper Relay ........... Wiper/Washer Systems
Windshield Washer Motor ....................... Wiper/Washer Systems
Wiper Motor ................................... Wiper/Washer Systems









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THROTTLE POSITION (TP) SWITCH or THROTTLE POSITION (TP) SENSOR in G \
-
TESTS W/CODES article.
Engine Coolant Temperature Sensor
See G - TESTS W/CODES article.
Heated Oxygen Sensor
See G - TESTS W/CODES article.
Intake Air Temperature (IAT) Sensor
On all models except Eclipse 2.0L non-turbo and Mirage 1.5L,
IAT sensor is a part of volume airflow sensor assembly. On all models,
see G - TESTS W/CODES article.
Manifold Absolute Pressure Sensor
See G - TESTS W/CODES article.
Manifold Differential Pressure Sensor
See G - TESTS W/CODES article.
Power Steering Oil Pressure (PSP) Switch
On Eclipse 2.0L non-turbo, see DTC 115 in G - TESTS W/CODES -
NON-TURBO article. On all other models except Eclipse 2.0L non-turbo,
see G - TESTS W/CODES article.
Throttle Position Sensor
See G - TESTS W/CODES article.
Vehicle Speed Sensor
See G - TESTS W/CODES article.
Volume Airflow Sensor
See G - TESTS W/CODES article.
MOTORS, RELAYS & SOLENOIDS
MOTORS
Idle Air Control Motor
See G - TESTS W/CODES article.
RELAYS
ASD, Fuel Pump & MFI Relay
See G - TESTS W/CODES article.
Radiator Cooling Fan Control Relay (High & Low)
See G - TESTS W/CODES article.
SOLENOIDS
EGR Control Solenoid Valve
See EXHAUST GAS RECIRCULATION (EGR) under EMISSION SYSTEMS &
SUB-SYSTEMS.
EVAP Purge Control Solenoid Valve
See FUEL EVAPORATION under EMISSION SYSTEMS & SUB-SYSTEMS.
Fuel Pressure Regulator Control Solenoid Valve (Turbo Models)
See FUEL DELIVERY under FUEL SYSTEM.
Wastegate Control Solenoid Valve

See TURBOCHARGER under AIR INDUCTION SYSTEMS.
FUEL SYSTEM
FUEL DELIVERY
NOTE: For fuel system pressure testing, see
F - BASIC TESTING article.
Fuel Pressure Regulator Control Solenoid Valve (Turbo Models)
See G - TESTS W/CODES article.
FUEL CONTROL
Fuel Injectors
See G - TESTS W/CODES article.
IDLE CONTROL SYSTEM
ELECTRICAL LOAD SWITCH
3000GT (DOHC)
1) Turn ignition off. Disconnect PCM connector. See
POWERTRAIN CONTROL MODULE (PCM) LOCATION table under COMPUTERIZED
ENGINE CONTROLS. Go to next step.
2) Turn headlights on. Using DVOM, check voltage between PCM
connector terminal No. 58 and chassis ground. If battery voltage is
present, turn headlights off and go to next step. If battery voltage
is not present, check and repair circuit between headlight relay
connector and PCM connector.
3) Turn defogger switch on. Using DVOM, check voltage between
PCM connector terminal No. 58 and chassis ground. If battery voltage
is present, turn defogger switch off and go to next step. If battery
voltage is not present, check and repair circuit between defogger
relay connector and PCM connector.
4) Turn blower switch on. Using DVOM, check voltage between
PCM connector terminal No. 58 and chassis ground. If battery voltage
is present, turn blower switch off and go to next step. If battery
voltage is not present, check and repair circuit between blower switch
connector and PCM connector.
5) If battery voltage is present and preceding tests do not
show any system or component malfunction and PCM is suspected,
substitute PCM with known-good unit and retest system.
IDLE AIR CONTROL (IAC) MOTOR
For testing procedures, see G - TESTS W/CODES article.
IGNITION SYSTEM
NOTE: For basic ignition checks, see F - BASIC TESTING article.
TIMING CONTROL SYSTEMS
Camshaft Position Sensor
See G - TESTS W/CODES article.
Crankshaft Position Sensor
See G - TESTS W/CODES article.