engine MITSUBISHI MONTERO 1991 Workshop Manual

Page 158 of 1333

exists in wire between alternator terminal "S" and positive battery
terminal or fusible link is blown.
4) Start engine. Ensure all lights and accessories are off.
Operate engine at 2500 RPM and read voltmeter when alternator output
current drops to 10 amps or less. Voltage regulator is okay if voltage
output is within specification. See REGULATOR VOLTAGE SPECIFICATIONS
table.
BENCH TESTING
RECTIFIER ASSEMBLY
1) Using ohmmeter, check for continuity between both diodes
and stator coil lead connection. See Fig. 11. Reverse leads. If
continuity exists in both directions, diode is shorted. Replace
rectifier assembly.
2) To check entire diode assembly, use an ohmmeter to check
for continuity between both ends of each diode. See Fig. 11. Switch
ohmmeter leads. Continuity should exist in one direction, but not
other. If no continuity exists or continuity exists in both
directions, diode is defective. Replace rectifier assembly.
Fig. 11: Testing Rectifier Assembly
Courtesy of Mitsubishi Motor Sales of America.
ROTOR

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\003
F - B ASIC T E STIN G

1991 M it s u bis h i M onte ro
1991 ENGINE PERFORMANCE
Basic Diagnostic Procedures
Chrysler; Colt, Colt 200, Colt Vista, Ram-50, Stealth,
Summit
Mitsubishi; Eclipse, Galant, Mirage, Montero, Pickup, 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. First step in diagnosing any driveability problem is
verifying customer's complaint with a test drive under conditions
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 computerized system,
perform each test listed in 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 distributor cap and rotor are
free of cracks, carbon trails or contamination. Ensure vacuum hoses
are properly routed and not pinched or cut. See M - VACUUM DIAGRAMS
article in the ENGINE PERFORMANCE Section 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. 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 engine's oiling
system.
COMPRESSION SPECIFICATIONS TABLE (1)
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Application Specification
psi (kg/cm)
1.5L (VIN X) .............................. 137 (9.6)
1.6L (VIN Y) ............................. 171 (12.0)
1.8L (VIN T) .............................. 131 (9.2)

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2.0L (VIN R) DOHC ......................... 137 (9.6)
2.0L (VIN U) DOHC Turbo ................... 114 (8.0)
2.0L (VIN V) SOHC ......................... 119 (8.4)
2.4L (VIN W) SOHC ......................... 119 (8.4)
3.0L (VIN S) SOHC ......................... 119 (8.4)
3.0L (VIN B) DOHC ......................... 139 (9.8)
3.0L (VIN C) DOHC Turbo ................... 115 (8.1)
(1) - Maximum variation between cylinders 14 psi
(1.0 kg/cm
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Exhaust System Backpressure
Exhaust system can be checked with a vacuum or pressure
gauge. Remove O2 sensor or air injection check valve (if equipped).
Connect a 1-10 psi pressure gauge and run engine at 2500 RPM. If
exhaust system backpressure is greater than 1 3/4-2 psi, exhaust
system or catalytic converter is plugged. If a vacuum gauge is used,
connect vacuum gauge hose to intake manifold vacuum port and start
engine. Observe vacuum gauge. Open throttle part way and hold steady.
If vacuum gauge reading slowly drops after stabilizing, exhaust system
should be checked for a restriction.
FUEL PRESSURE
Basic diagnosis of fuel system should begin with determining
fuel system pressure.
FUEL INJECTED ENGINES
WARNING: ALWAYS relieve fuel pressure before disconnecting any fuel
injection-related component. DO NOT allow fuel to contact
engine or electrical components.
Fuel Pressure
1) On all models except Colt and Mirage, disconnect fuel pump
harness connector at fuel tank. On Colt and Mirage, remove rear seat
cushion to disconnect fuel pump harness connector.
2) On all models, start engine. Let engine run until it
stops. Turn ignition off. Disconnect negative battery terminal.
Connect fuel pump harness connector.
WARNING: Before disconnecting high pressure fuel hose at fuel delivery
pipe, cover fuel hose connection with a rag. Some residual
fuel pressure may still be in system.
3) On Galant 2.0L (DOHC), remove brace for access to high
pressure fuel delivery pipe. On all engines, disconnect high pressure
fuel hose at fuel delivery pipe.
4) Connect fuel pressure gauge with adapter between fuel
delivery pipe and high pressure hose. See Fig. 1. Connect negative
battery terminal. Connect battery voltage to fuel pump test terminal.
See FUEL PUMP TEST TERMINAL LOCATION table. Ensure no fuel leaks are
present. Disconnect battery voltage to fuel pump test terminal.

Page 164 of 1333

Fig. 1: Fuel Pressure Testing Connection ID (Typical Fuel Inj. Eng.)
Courtesy of Mitsubishi Motor Sales of America.
5) Start engine and let idle. Measure fuel pressure with
vacuum hose connected to fuel pressure regulator. Record fuel pressure
reading. Disconnect and plug vacuum hose from fuel pressure regulator.
Record fuel pressure reading. See REGULATED FUEL PRESSURE table.
6) 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.
7) Turn engine off. Ensure fuel pressure reading does not
decrease within 2 minutes. If a decrease is noted, monitor speed of
decrease.
8) 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, faulty fuel pressure regulator, or fuel pump.
9) If fuel pressure is higher 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.
10) If fuel pressure decreases suddenly after engine is
stopped, check valve within fuel pump is not seated. Replace fuel

Page 165 of 1333

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 required.
11) When fuel pressure test is complete, repeat fuel pressure
release procedure in steps 1) and 2) before disconnecting fuel
pressure gauge. Install new "O" ring at end of high pressure hose.
Check for fuel leaks.
FUEL PUMP TEST TERMINAL LOCATION TABLE
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Application Wire Color Location
Colt, Colt 200 ......... BLK/WHT .............. Center Of Firewall
Colt Vista ............. BLK/WHT ........ Right Center Of Firewall
Eclipse ................ BLK/WHT .......... Rear Of Battery Compt.
Galant ................. YEL/GRN ........... Left Rear Eng. Compt.
Mirage 1.5L ............ BLK/WHT .............. Center Of Firewall
Mirage 1.6L ............ BLK/BLU .............. Center Of Firewall
Montero .................. WHT .......... Right Center Of Firewall
Pickup ................. BLK/BLU ....... Right Side Of Eng. Compt.
Precis ................... YEL ............. Left Rear Eng. Compt.
Summit ................. BLK/WHT .............. Center Of Firewall
Ram-50 ................. BLK/BLU ....... Right Side Of Eng. Compt.
Stealth, 3000GT ........ BLK/BLU .......... Rear Of Battery Compt.
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REGULATED FUEL PRESSURE TABLE\
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At Idle At Idle
w/Vacuum w/o Vacuum
Application psi (kg/cm
) psi (kg/cm)
Non-Turbo .................. 38 (2.7) ....... 47-50 (3.3-3.5)
Turbo
Except Eclipse A/T ....... 27 (1.9) ....... 36-38 (2.5-2.7)
Eclipse A/T .............. 33 (2.3) ....... 36-38 (2.9-3.2)
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Control Relay
Multipurpose relay switches power to vehicle sensors and
actuators including airflow sensor, crank angle sensor, idle speed
control, injectors and fuel pump. When ignition switch is turned to ON
position, ECU energizes coils controlling injectors, airflow sensor
and idle speed control. When ignition switch is turned to START
position, ECU energizes coils (through inhibitor switch on A/T models)\
to supply power to fuel pump. Relay failure will cause a no-start
condition. For testing procedure, see SYSTEM & COMPONENT TESTING
article.
IGNITION CHECKS
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. For wire resistance specification,
see C - SPECIFICATIONS article in the ENGINE PERFORMANCE Section.
CRANK ANGLE SENSOR
For crank angle sensor testing procedure on all models except
Ram-50, Stealth, Eclipse, Laser, Pickup and 3000GT, see TEST NS-5:

Page 166 of 1333

TESTING CRANK ANGLE SENSOR CIRCUIT - G - TESTS W/CODES article in the
ENGINE PERFORMANCE section.
On Eclipse and Laser, see NS-4A: REPAIRING CRANK ANGLE SENSOR
in G - TESTS W/CODES - 1.8L article.
On Ram-50, Stealth, Pickup and 3000GT testing information not
available at time of publication.
DISTRIBUTORLESS IGNITION SYSTEM (DIS)
Ignition Coil Resistance (4-Cyl Vehicles Except Eclipse 2.0L)
1) Using a Digital Volt/Ohmmeter (DVOM), measure primary coi\
l
resistance between ignition coil connector terminals No. 2 and No. 3
(coils for cylinders No. 1 and No. 4) and terminals No. 1 and No. 3
(coils for cylinders No. 2 and No. 3). See Fig. 2.
Fig. 2: Testing Ignition Coil Primary Resistance (4-Cylinder)
Courtesy of Mitsubishi Motor Sales of America.
2) Measure secondary coil resistance between coil towers for
cylinders No. 1 and No. 4 and between coil towers for cylinders No. 2
and No. 3. See Fig. 3. Primary and secondary coil resistance should be
within specification. See DIS IGNITION COIL RESISTANCE table.
Fig. 3: Testing Ignition Coil Secondary Resistance (4-Cylinder)
Courtesy of Mitsubishi Motor Sales of America.

Page 173 of 1333

Application Primary Secondary
1.5L (VIN A) ........... .9-1.2 .......... 20,000-29,000
1.8L (VIN T)
Except Eclipse ....... .72-.88 ......... 10,300-13,900
Eclipse .............. .90-1.2 ......... 19,000-27,000
2.0L (VIN V) ........... .72-.88 ......... 10,800-13,200
2.4L (VIN W) ........... .72-.88 ......... 10,300-13,900
3.0L (VIN B & C) ....... .67-.81 ......... 11,300-15,300
3.0L (VIN S) ........... .72-.88 ......... 10,300-13,900
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IGNITION TIMING
IGNITION TIMING TABLE (Degrees BTDC @ RPM)\
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Application (1) Basic (2)(3) Actual
1.5L
Colt, Colt
200 & Mirage ......... 5 @ 600-800 ..... 10 @ 600-800
Colt Vista ............ 5 @ 600-800 ..... 15 @ 600-800
1.6L
Colt, Colt 200
Mirage & Summit ...... 5 @ 650-850 ...... 8 @ 650-850
1.8L
Colt Vista ............ 5 @ 600-800 ..... 15 @ 600-800
Eclipse ............... 5 @ 600-800 ..... 10 @ 600-800
2.0L
Colt Vista
& Galant (VIN V) ..... 5 @ 650-850 ..... 12 @ 650-850
Eclipse ............... 5 @ 650-850 ...... 8 @ 650-850
Galant (VIN R) ........ 5 @ 650-850 ...... 8 @ 650-850
2.4L
Pickup, Ram-50 ........ 5 @ 650-850 ...... 8 @ 650-850
3.0L
Montero,
Stealth & 3000GT ..... 5 @ 600-800 ..... 15 @ 600-800
Pickup & Ram-50 ....... 8 @ 600-800 ..... 15 @ 600-800
(1) - With ignition timing adjustment connector grounded or
vacuum hose (farthest from distributor) disconnected.
(2) - With ignition timing adjustment connector ungrounded
or vacuum hose (farthest from distributor) connected.
Ignition timing may fluctuate.
(3) - If vehicle altitude is more than 2300 ft. above sea
level, actual timing may be advanced.
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SUMMARY
If no faults were found while performing F - BASIC TESTING,
proceed to G - TESTS W/ CODES article in the ENGINE PERFORMANCE
Section. If no hard codes are found in self-diagnostics, proceed to H
- TESTS W/O CODES article in the ENGINE PERFORMANCE Section for
diagnosis by symptom (i.e., ROUGH IDLE, NO-START, etc.), or
intermittent diagnostic procedures.

Page 175 of 1333

SHOE HARDWARE
SHOES
SOCKETS
SPEED SENSORS (ELECTRONIC WHEEL AND VEHICLE)
STEEL BRAKE LINES
STOPLIGHT SWITCHES
SWITCHES
TIRES
TOOTHED RINGS (TONE WHEEL)
VACUUM BOOSTERS
VACUUM HOSES
VALVES
WHEEL ATTACHING HARDWARE
WHEEL BEARINGS, RACES AND SEALS
WHEEL CYLINDERS
WIRING HARNESSES
INTRODUCTION TO MOTORIST ASSURANCE PROGRAM (MAP)
OVERVIEW OF MOTORIST ASSURANCE PROGRAM
The Motorist Assurance Program is the consumer outreach
effort of the Automotive Maintenance and Repair Association, Inc.
(AMRA). Participation in the Motorist Assurance Program is drawn from
retailers, suppliers, independent repair facilities, vehicle
manufacturers and industry associations.
Our organization's mission is to strengthen the relationship
between the consumer and the auto repair industry. We produce
materials that give motorists the information and encouragement to
take greater responsibility for their vehicles-through proper,
manufacturer-recommended, maintenance. We encourage participating
service and repair shops (including franchisees and dealers) to adopt:\
1) a Pledge of Assurance to their Customers and
2) the Motorist Assurance Program Standards of Service.
All participating service providers have agreed to subscribe
to this Pledge and to adhere to the promulgated Standards of Service
demonstrating to their customers that they are serious about customer
satisfaction.
These Standards of Service require that an inspection of the
vehicle's (problem) system be made and the results communicated to the\
customer according to industry standards. Given that the industry did
not have such standards, the Motorist Assurance Program successfully
promulgated industry inspection communication standards in 1994-95 for
the following systems: Exhaust, Brakes, ABS, Steering and Suspension,
Engine Maintenance and Performance, HVAC, and Electrical Systems.
Further, revisions to all of these inspection communication standards
are continually re-published. In addition to these, standards for
Drive Train and Transmissions have recently been promulgated.
Participating shops utilize these Uniform Inspection & Communication
Standards as part of the inspection process and for communicating
their findings to their customers.
The Motorist Assurance Program continues to work
cooperatively and proactively with government agencies and consumer
groups toward solutions that both benefit the customer and are
mutually acceptable to both regulators and industry. We maintain the
belief that industry must retain control over how we conduct our
business, and we must be viewed as part of the solution and not part
of the problem. Meetings with state and other government officials
(and their representatives), concerned with auto repair and/or
consumer protection, are conducted. Feedback from these sessions is
brought back to the association, and the program adjusted as needed.
To assure auto repair customers recourse if they were not

Page 176 of 1333

satisfied with a repair transaction, the Motorist Assurance Program
offers mediation and arbitration through MAP/BBB-CARE and other non-
profit organizations. MAP conducted pilot programs in twelve states
before announcing the program nationally in October, 1998. During the
pilots, participating repair shops demonstrated their adherence to the
Pledge and Standards and agreed to follow the UICS in communicating
the results of their inspection to their customers. To put some
"teeth" in the program, an accreditation requirement for shops was
initiated. The requirements are stringent, and a self-policing method
has been incorporated which includes the "mystery shopping" of
outlets.
We welcome you to join us as we continue our outreach with
your support, both the automotive repair industry and your customers
will reap the benefits. Please visit MAP at our Internet site www.
motorist.org or contact us at:
1444 I Street, NW Suite 700
Washington, DC 20005
Phone (202) 712-9042 Fax (202) 216-9646
January 1999
MAP UNIFORM INSPECTION GENERAL GUIDELINES
OVERVIEW OF SERVICE REQUIREMENTS AND SUGGESTIONS
It is MAP policy that all exhaust, brake, steering,
suspension, wheel alignment, drive-line, engine performance and
maintenance, and heating, ventilation and air conditioning, and
electrical services be offered and performed under the standards and
procedures specified in these sections.
Before any service is performed on a vehicle, an inspection
of the appropriate system must be performed. The results of this
inspection must be explained to the customer and documented on an
inspection form. The condition of the vehicle and its components will
indicate what services/part replacements may be "Required" or
"Suggested". In addition, suggestions may be made to satisfy the
requests expressed by the customer.
When a component is suggested or required to be repaired or
replaced, the decision to repair or replace must be made in the
customer's best interest, and at his or her choice given the options
available.
This section lists the various parts and conditions that
indicate a required or suggested service or part replacement.
Although this list is extensive, it is not fully inclusive. In
addition to this list, a technician may make a suggestion. However,
any suggestions must be based on substantial and informed experience,
or the vehicle manufacturer's recommended service interval and must be
documented.
Some conditions indicate that service or part replacement is
required because the part in question is no longer providing the
function for which it is intended, does not meet a vehicle
manufacturer's design specification or is missing.
Example:
An exhaust pipe has corroded severely and has a hole in it
through which exhaust gases are leaking. Replacement of the
exhaust pipe in this case is required due to functional
failure.
Example:
A brake rotor has been worn to the point where it measures
less than the vehicle manufacturer's discard specifications.

Page 186 of 1333

same axle to eliminate uneven braking behavior. Always wash drums
after servicing or before installing.
DRUM INSPECTION
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Condition Code Procedure
Balance weight missing .. .. ........ No service suggested or
required.
Bell-mouthed, affecting
performance ............ A ....... Require reconditioning or
replacement.
Cooling fin broken ...... .. ........ No service suggested or
required.
Cracked ................. B ............ Require replacement.
Drum diameter is greater
than OEM "machine to"
specifications but less
than "discard at"
specifications, and the
drum does not require
reconditioning ......... 1 ........ (1) Suggest replacement.
Drum diameter will exceed
OEM "machine to"
specifications after
required
reconditioning ......... B ........ ( 2) Require replacement.
Hard-spotted ............ 2 ....... Suggest reconditioning or
replacement.
Measured diameter is
greater than OEM discard
specifications ......... B ............ Require replacement.
Out-of-round (runout),
affecting performance .. A ....... Require reconditioning or
replacement.
Out-of-round (runout),
exceeding manufacturer's
specifications ......... B ....... Require reconditioning or
replacement.
Scored .................. B ....... Require reconditioning or
replacement.
Surface threaded due to
improper machining ..... B ....... Require reconditioning or
replacement.
Tapered, affecting
performance ............ A ....... Require reconditioning or
replacement.
( 1) - Only applies to vehicles for which OEM "machine to"
specifications exist. If OEM does not supply "machine to"
specifications, the drum may be worn to discard
specifications.
( 2) - If OEM does not supply "machine to" specifications, you
may machine to discard specifications.
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ELECTRICAL PUMPS AND MOTORS
Copied fuel pump conditions from engine UIGs & deleted
pulsator from leaking conditions.
ELECTRICAL PUMP AND MOTOR INSPECTION
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