MITSUBISHI MONTERO 1998 Service Manual
Page 701 of 1501
leaking) ............... A ............ Require replacement.
Sound quality
unsatisfactory ......... 2 .. Suggest replacement to address
customer need and/or request.
Split (exhaust leaking) . A ............ Require replacement.
Weak due to corrosion, but
no leaks present ....... 1 ............ Suggest replacement.
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F - BASIC TESTING
1998 Mitsubishi Montero
1998 ENGINE PERFORMANCE
Mitsubishi - Basic Diagnostic Procedures
Diamante, Eclipse, Galant, Mirage, Montero, Montero Sport,
3000GT
INTRODUCTION
The following diagnostic steps will help prevent overlooking
a simple problem. This is also where to begin diagnosis for a no-start
condition. The first step in diagnosing any driveability problem is
verifying the customer's complaint with a test drive under the
conditions the problem reportedly occurred.
Before entering self-diagnostics, perform a careful and
complete visual inspection. Most engine control problems result from
mechanical breakdowns, poor electrical connections or
damaged/misrouted vacuum hoses. Before condemning the computerized
system, perform each test listed in this article.
NOTE: Perform all voltage tests with a Digital Volt-Ohmmeter
(DVOM) with a minimum 10-megohm input impedance, unless
stated otherwise in test procedure.
PRELIMINARY INSPECTION & ADJUSTMENTS
VISUAL INSPECTION
Visually inspect all electrical wiring, looking for chafed,
stretched, cut or pinched wiring. Ensure electrical connectors fit
tightly and are not corroded. Ensure vacuum hoses are properly routed
and are not pinched or cut. See M - VACUUM DIAGRAMS article to verify
routing and connections (if necessary). Inspect air induction system
for possible vacuum leaks.
MECHANICAL INSPECTION
Compression
Check engine mechanical condition with a compression gauge,
vacuum gauge, or an engine analyzer. See engine analyzer manual for
specific instructions.
WARNING: DO NOT use ignition switch during compression tests on fuel
injected vehicles. Use a remote starter to crank engine.
Fuel injectors on many models are triggered by ignition
switch during cranking mode, which can create a fire hazard
or contaminate the engine's oiling system.
Check engine compression with engine at normal operating
temperature, all spark plugs removed and throttle wide open. See
COMPRESSION SPECIFICATIONS table.
COMPRESSION SPECIFICATIONS TABLE
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Application (1) Specification
Compression Ratio
1.5L (VIN A) ..................................... 9.0:1
1.8L (VIN C) ..................................... 9.5:1
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2.0L
(VIN F) ........................................ 8.5:1
(VIN Y) ........................................ 9.6:1
2.4L (VIN G) ..................................... 9.5:1
3.0L
(VIN H) ........................................ 8.9:1
(VIN J) ....................................... 10.0:1
(VIN K) ........................................ 8.0:1
(VIN P) ........................................ 9.0:1
3.5L (VIN M & P) ................................. 9.0:1
Compression Pressure
1.5L (VIN A) ..................... 192 psi (13.4 kg/cm
)
1.8L (VIN C) ..................... 199 psi (13.9 kg/cm)
2.0L (VIN F) ..................... 178 psi (12.5 kg/cm)
2.0L (VIN Y) ............ 170-225 psi (11.7-15.5 kg/cm)
2.4L (VIN G) ..................... 192 psi (13.4 kg/cm)
3.0L
(VIN H & P) .................... 171 psi (12.0 kg/cm
)
(VIN J) ........................ 185 psi (13.0 kg/cm)
(VIN K) ........................ 156 psi (10.9 kg/cm)
3.5L (VIN M & P) ................. 171 psi (12.0 kg/cm)
Maximum Variation
Between Cylinders ( 2) ............... 14 psi (1.0 kg/cm
)
( 1) - See A - ENGINE/VIN ID article for VIN information.
( 2) - On Eclipse 2.0L non-turbo engine, maximum variation
between cylinders is 25%.
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Exhaust System Backpressure
The exhaust system can be tested with a vacuum or pressure
gauge. If using a pressure gauge, remove HO2S or air injection check
valve (if equipped). Connect a 0-5 psi pressure gauge and run engine
at 2500 RPM. If exhaust system backpressure is greater than 2 psi,
exhaust system or catalytic converter is plugged.
If using a vacuum gauge, connect vacuum gauge hose to intake
manifold vacuum port. Start engine. Observe vacuum gauge. Open
throttle part way and hold steady. If vacuum gauge indication slowly
drops after stabilizing, inspect exhaust system for restriction.
FUEL SYSTEM
* PLEASE READ THIS FIRST *
WARNING: ALWAYS relieve fuel pressure before disconnecting any fuel
injection-related component. DO NOT allow fuel to contact
engine or electrical components.
RELIEVING FUEL PRESSURE
1) On Diamante, disconnect fuel pump harness connector at
fuel tank from underneath vehicle. On Montero and Montero Sport,
remove cargo compartment carpet, remove access plate and disconnect
fuel pump harness connector. On all other models, remove rear seat
cushion, remove access plate (if required) and disconnect fuel pump
harness connector.
2) On all models, start engine. Let engine run until it
stops. Turn ignition off. Disconnect negative battery cable. Connect
fuel pump harness connector. Install rear seat and/or carpet as
necessary.
WARNING: Before disconnecting high pressure fuel hose at fuel
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delivery pipe, cover fuel hose connection with a rag. Some
residual fuel pressure may still be in system.
FUEL PRESSURE
1) Relieve fuel pressure. See RELIEVING FUEL PRESSURE. On
models with fuel rail service valve, connect fuel pressure gauge to
fuel rail. On models without fuel rail service valve, disconnect high
pressure fuel inlet line at fuel rail. Remove throttle body bracket
(if necessary). Connect fuel pressure gauge with adapter between fuel
rail and high pressure fuel inlet line. See Fig. 1.
Fig. 1: Installing Fuel Pressure Tester (Typical)
Courtesy of Mitsubishi Motor Sales of America
2) On Eclipse 2.0L non-turbo and Montero Sport, use scan tool
to operate fuel pump. On all other models, operate fuel pump by
connecting battery voltage to fuel pump test terminal. See
FUEL PUMP TEST TERMINAL LOCATION table. Ensure no fuel leaks are
present. Disconnect battery voltage from fuel pump test terminal.
FUEL PUMP TEST TERMINAL LOCATION TABLE
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Application Wire Color Location
Diamante .................. Black/Blue ............ (1)
Eclipse (Turbo & 2.4L) .... Black/Blue ............. ( 2)
Galant .................... Black/Blue ............ ( 3)
Mirage .................... Black/Blue ............ ( 1)
Montero ...................... White .............. ( 4)
3000GT .................... Black/Blue ............ ( 6)
( 1) - On firewall, above brake master cylinder.
( 2) - On firewall behind battery.
( 3) - On main wiring harness, near center of firewall.
( 4) - On main wiring harness, near right center of firewall.
( 5) - Near left rear corner of engine compartment, below
cruise control actuator (if equipped).
( 6) - On main wiring harness, near wiper motor on firewall,
behind battery.
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3) Start engine and allow it to idle. Measure fuel pressure
with vacuum hose connected to fuel pressure regulator. Record fuel
pressure reading. See FUEL PUMP PERFORMANCE table. Disconnect and plug
vacuum hose from fuel pressure regulator. Record fuel pressure
reading.
4) Check for fuel pressure in fuel return hose by gently
pinching hose while increasing engine speed. If fuel volume is low,
fuel pressure in return hose will not be felt. Increase engine speed
to 2500-3000 RPM, 2-3 times. Return engine to idle. Fuel pressure
should not drop when engine is returned to idle.
5) Turn ignition off. Ensure fuel pressure reading does not
decrease within 2 minutes. If a decrease is noted, monitor speed of
decrease.
6) If fuel pressure is lower than specification, fuel
pressure drops at idle after increasing engine speed to 2500-3000 RPM,
or no fuel pressure in fuel return hose can be felt, check for clogged
fuel filter, or faulty fuel pressure regulator or fuel pump.
7) If fuel pressure is greater than specification, check for
a faulty fuel pressure regulator or plugged fuel return line. If fuel
pressure does not change when vacuum hose to regulator is connected or
disconnected, check for a leaking or clogged vacuum hose to fuel
pressure regulator or faulty fuel pressure regulator.
8) If fuel pressure decreases suddenly after engine is
stopped, check valve in fuel pump is not seated. Replace fuel pump. If
fuel pressure drops slowly, fuel injector is leaking or fuel pressure
regulator valve seat is leaking. Check for faulty fuel injector or
fuel pressure regulator. Repair as necessary.
9) When fuel pressure test is complete, repeat fuel pressure
release procedure before disconnecting fuel pressure gauge. Install
NEW "O" ring at end of high pressure fuel inlet line. Check for fuel
leaks.
FUEL PUMP PERFORMANCE TABLE
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At Idle w/Vacuum At Idle w/o Vacuum
Application psi (kg/cm) psi (kg/cm)
Eclipse 2.0L
Non-Turbo ........... ( 1) ............ 47-50 (3.3-3.5)
Turbo ............. 33 (2.3) ......... 42-45 (3.0-3.5)
3000GT Turbo ........ 34 (2.4) ......... 43-45 (3.0-3.1)
All Other Models .... 38 (2.7) ......... 47-50 (3.3-3.5)
( 1) - Information is not available from manufacturer at time
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MFI CONTROL RELAY
MFI control relay switches power to vehicle sensors and
actuators including Volume Airflow (VAF) sensor, crankshaft position
sensor, idle speed control, injectors and fuel pump. When ignition
switch is turned to RUN position, PCM energizes coils controlling
injectors, VAF sensor and idle air control. When ignition switch is
turned to START position, PCM energizes coils (through park/neutral
position switch on A/T models) to supply power to fuel pump. Relay
failure will cause a no-start condition. For testing procedure, see I
- SYSTEM/COMPONENT TESTS article.
IGNITION CHECKS
* PLEASE READ THIS FIRST *
NOTE: Perform all circuit tests with a Digital Volt-Ohmmeter
(DVOM) with a minimum 10-megohm input impedance, unless
stated otherwise in test procedure.
SPARK
Check for spark at coil wire (if applicable) and at each
spark plug wire using a high output spark tester. Check spark plug
wire resistance on suspect wires. Wire resistance should not exceed
22,000 ohms for all models except Eclipse 2.0L non-turbo and Montero.
On Eclipse 2.0L non-turbo, resistance should not exceed 8000 ohms. On
Montero, resistance should not exceed 26,000 ohms.
CAMSHAFT POSITION (CMP) SENSOR
For CMP sensor testing procedure, see G - TESTS W/CODES
article.
CRANKSHAFT POSITION (CKP) SENSOR
For CKP sensor testing procedure, see G - TESTS W/CODES
article.
DISTRIBUTORLESS IGNITION SYSTEM (DIS - 4-CYLINDER)
Ignition Coil Resistance (Eclipse)
1) On Mirage 1.8L, see POWER TRANSISTOR (MIRAGE). On Eclipse\
2.0L non-turbo, go to step 3). On Eclipse 2.0L turbo and 2.4L,
disconnect ignition coil connector. Go to next step.
2) On Eclipse 2.0L turbo, use DVOM to measure primary coil
resistance between ignition coil connector terminals No. 2 and 3 (coil
for cylinders No. 1 and 4) and terminals No. 1 and 3 (coil for
cylinders No. 2 and 3). See Fig. 3. On Eclipse 2.4L, use DVOM to
measure primary coil resistance Between ignition coil terminals. Go to
step 4).
Fig. 2: Ignition Coil Connector Terminals (Eclipse 2.0L Non-Turbo)
Courtesy of Mitsubishi Motor Sales of America
Page 707 of 1501
Fig. 3: Ignition Coil Connector Terminals (Eclipse 2.0L Turbo)
Courtesy of Mitsubishi Motor Sales of America
3) Disconnect ignition coil connector. Using DVOM, measure
primary coil resistance at coil (component side) 3-pin connector.
Page 708 of 1501
Measure between center and right terminals of connector for cylinders
No. 1 and 4, and between center and left terminals of connector for
cylinders No. 2 and 3.
4) On all models, remove ignition wires from coil. Measure
secondary coil resistance between coil towers for cylinders No. 1 and
4 and between coil towers for cylinders No. 2 and 3. Primary and
secondary coil resistance should be within specification. See
IGNITION COIL RESISTANCE (ECLIPSE) table. Connect coil harness
connector. Connect ignition wires to coil.
IGNITION COIL RESISTANCE (ECLIPSE) - Ohms @ 68
F (20C) TABLE \
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Application Primary Secondary
2.0L
Non-Turbo ............ .51-.61 ......... 11,500-13,500
Turbo ................ .70-.86 ......... 11,300-15,300
2.4L ................... .74-.90 ......... 20,100-27,300
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Power Transistor (Eclipse 2.0L Turbo & 2.4L)
1) To test the section of the power transistor that controls
cylinders No. 1 and 4, disconnect power transistor connector. Using a
1.5-volt dry cell battery, connect negative end of battery to terminal
No. 3 of power transistor and positive end to terminal No. 7. See
Fig. 4 .
Fig. 4: Identifying Power Transistor Connector Terminals (Eclipse
2.0L Turbo & 2.4L)
Courtesy of Mitsubishi Motor Sales of America
2) Using an analog ohmmeter, check for continuity between
terminals No. 3 and 8 of power transistor. Continuity should exist.
With positive end of 1.5-volt battery disconnected, there should be no
continuity. Replace power transistor if it fails test.
3) To test the section of the power transistor that controls
cylinders No. 2 and 3, connect negative end of 1.5-volt dry cell
battery to terminal No. 3 of power transistor and positive end to
terminal No. 2.
4) Using an analog ohmmeter, check for continuity between
terminals No. 1 and 3 of power transistor. Continuity should exist.
With positive end of 1.5-volt battery disconnected, there should be no
continuity. Replace power transistor if it fails test.
Power Transistor (Mirage)
1) Disconnect power transistor (distributor) connector. Usin\
g
a 1.5-volt dry cell battery, connect negative end of battery to
terminal No. 4 of power transistor and positive end to terminal No. 3.
See Fig. 5 .
Page 709 of 1501
Fig. 5: Power Transistor Connector Terminals (Mirage 1.8L)
Courtesy of Mitsubishi Motor Sales of America
2) Using an analog ohmmeter, check for continuity between
terminals No. 2 and 3 of power transistor. Continuity should exist.
With positive end of 1.5-volt battery disconnected, there should be no
continuity. Replace power transistor if it fails test.
DISTRIBUTORLESS IGNITION SYSTEM (DIS - V6)
Ignition Coil Resistance
1) On 3000GT DOHC, go to next step. On Montero and Montero
Sport, use DVOM to measure primary coil resistance between each
individual coil. To check secondary coil resistance, measure
resistance between towers of each individual coil. Replace coil if
primary and secondary coil resistances are not within specification.
See IGNITION COIL RESISTANCE (V6) table.
2) Using DVOM, measure primary coil resistance between
terminal No. 3 (power terminal) and each individual coil terminal. See\
Fig. 6 . Terminal No. 1 controls coil "B", terminal No. 2 controls coil
"A", and terminal No. 4 controls coil "C". See Fig. 7. To check
secondary coil resistance, measure resistance between towers of each
individual coil. Replace coil if primary and secondary coil
Page 710 of 1501
resistances are not within specification. See
IGNITION COIL RESISTANCE (V6) table.
IGNITION COIL RESISTANCE (V6) - Ohms @ 68
F (20C) TABLE \
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Application Primary Secondary
3.0L
VIN J & K ............ .67-.81 ......... 11,300-15,300
VIN P ................ .74-.90 ......... 20,100-27,300
3.5L (VIN M) ........... .74-.90 ......... 20,100-27,300
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Fig. 6: Identifying Ignition Coil Terminals (3000GT DOHC)
Courtesy of Mitsubishi Motor Sales of America