spark plugs MITSUBISHI MONTERO 1991 User Guide
[x] Cancel search | Manufacturer: MITSUBISHI, Model Year: 1991, Model line: MONTERO, Model: MITSUBISHI MONTERO 1991Pages: 1333, PDF Size: 24.61 MB
Page 737 of 1333
Air Filter ....................... 30,000
Automatic Transaxle Fluid ........ 30,000
Belts ............................ 30,000
Coolant .......................... 30,000
Fuel & Vapor Hoses ............... 50,000
Oil
Non-Turbo ........................ 7500
Turbo ............................ 5000
Oil Filter
Non-Turbo ...................... 15,000
Turbo .......................... 10,000
Spark Plugs ...................... 30,000
Timing Belt ...................... 60,000
Galant
Air Filter ....................... 30,000
Automatic Transaxle Fluid ........ 30,000
Belts ............................ 30,000
Coolant .......................... 30,000
Fuel & Vapor Hoses ............... 50,000
Oil
Non-Turbo ........................ 7500
Turbo ............................ 5000
Oil Filter
Non-Turbo ...................... 15,000
Turbo .......................... 10,000
Rear Axle Fluid .................. 30,000
Spark Plugs ...................... 30,000
Timing & Balance Shaft Belts ..... 60,000
Montero
Air Filter ....................... 30,000
Automatic Transmission Fluid ..... 30,000
Belts ............................ 30,000
Coolant .......................... 30,000
Front & Rear Axle Fluid .......... 30,000
Fuel Filter ...................... 50,000
Fuel & Vapor Hoses ............... 50,000
Oil ................................ 7500
Oil Filter ....................... 15,000
O2 Sensor (2) .................... 80,000
Spark Plugs ...................... 30,000
Spark Plug Wires ( 2) ............. 60,000
Timing Belt ...................... 60,000
Transfer Case Fluid .............. 30,000
Vapor Canister ( 2) .............. 100,000
Pickup & Ram-50
Air Filter ....................... 30,000
Automatic Transmission Fluid ..... 30,000
Belts ............................ 30,000
Coolant .......................... 30,000
EGR Valve (2.4L) ( 2) ............. 50,000
Front & Rear Axle Fluid .......... 30,000
Fuel Filter ...................... 50,000
Fuel & Vapor Hoses ............... 50,000
Oil ................................ 7500
Oil Filter ....................... 15,000
O2 Sensor ( 2) .................... 80,000
Spark Plugs ...................... 30,000
Spark Plug Wires ( 2) ............. 60,000
Timing Belt ...................... 60,000
Transfer Case Fluid .............. 30,000
Vapor Canister ( 2) .............. 100,000
Stealth
Air Filter ....................... 30,000
Page 738 of 1333
Automatic Transaxle Fluid ........ 30,000
Belts ............................ 30,000
Coolant .......................... 30,000
Front & Rear Axle Fluid .......... 30,000
Fuel & Vapor Hoses ............... 50,000
Oil
Non-Turbo ........................ 7500
Turbo ............................ 5000
Oil Filter
Non-Turbo ...................... 15,000
Turbo .......................... 10,000
Spark Plugs ...................... 60,000
Timing Belt ...................... 60,000
3000GT
Air Filter ....................... 30,000
Belts ............................ 30,000
Coolant .......................... 30,000
Fuel & Vapor Hoses ............... 50,000
Front & Rear Axle Fluid .......... 30,000
Oil
Non-Turbo ........................ 7500
Turbo ............................ 5000
Oil Filter
Non-Turbo ...................... 15,000
Turbo .......................... 10,000
Spark Plugs ...................... 60,000
Timing Belt ...................... 60,000
(1) - Federal 4WD models only.
( 2) - Federal models only.
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BELT ADJUSTMENT \
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Deflection
Application ( 1) In. (mm)
Colt, Colt 200, Mirage & Summit
1.5L ...................................... .28-.35 (7.1-8.9)
1.6L ..................................... .35-.45 (8.9-11.4)
Colt Vista
2.0L ..................................... .28-.40 (7.1-10.2)
Eclipse
1.8L ..................................... .32-.43 (8.1-11.1)
2.0L ..................................... .35-.45 (8.9-11.4)
Galant
Alternator Belt .......................... .35-.45 (8.9-11.4)
A/C Belt .......................................... .32 (8.1)
Power Steering Belt ....................... .24-.35 (6.1-8.9)
Montero
3.0L ...................................... .20-.24 (5.1-6.1)
Pickup & Ram-50
2.4L ...................................... .27-.39 (6.8-9.9)
3.0L ...................................... .32-.39 (8.1-9.9)
Stealth & 3000GT
SOHC
Alternator & Power Steering Belt ........ .24-.35 (6.1-8.9)
A/C Belt ................................ .28-.37 (7.1-9.5)
DOHC
Alternator Belt (With or Without A/C) ... .16-.22 (4.1-5.6)
Power Steering Belt .................... .35-.43 (8.9-11.1)
( 1) - With 22 lbs. (10 kg) pressure applied midway on belt run.
Page 739 of 1333
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MECHANICAL CHECKS
ENGINE COMPRESSION](/img/19/57332/w960_57332-738.png "MITSUBISHI MONTERO 1991 User Guide \
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MECHANICAL CHECKS
ENGINE COMPRESSION")
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MECHANICAL CHECKS
ENGINE COMPRESSION
Check engine compression with engine at normal operating
temperature at specified cranking speed, all spark plugs removed and
throttle wide open.
COMPRESSION SPECIFICATIONS
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Application (1) Specification
Compression Ratio
1.5L (VIN A) ...................... 9.4:1
1.6L (VIN Y) ...................... 9.2:1
1.8L (VIN T) ...................... 9.0:1
2.0L (VIN R) ...................... 9.0:1
2.0L (VIN U) ...................... 9.0:1
2.0L (VIN V) ...................... 8.5:1
2.4L (VIN W) ...................... 8.5:1
3.0L (VIN B) ..................... 10.0:1
3.0L (VIN C) ...................... 8.0:1
3.0L (VIN S) ...................... 8.9:1
Compression Pressure ( 2)
1.5L (VIN A) ....... 137 psi (9.6 kg/cm
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1.6L (VIN Y) ...... 171 psi (12.0 kg/cm)
1.8L (VIN T) ....... 131 psi (9.2 kg/cm)
2.0L (VIN R) ....... 137 psi (9.6 kg/cm)
2.0L (VIN U) ....... 114 psi (8.0 kg/cm)
2.0L (VIN V) ....... 119 psi (8.4 kg/cm)
2.4L (VIN W) ....... 119 psi (8.4 kg/cm)
3.0L (VIN B) ....... 139 psi (9.8 kg/cm)
3.0L (VIN C) ....... 115 psi (8.1 kg/cm)
3.0L (VIN S) ....... 119 psi (8.4 kg/cm)
( 1) - See A - ENGINE/VIN ID article in the
ENGINE PERFORMANCE Section for VIN
information.
( 2) - Maximum variation between cylinders is
14 psi (1.0 kg/cm
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VALVE CLEARANCE
NOTE: Valve adjustment is required on 1.5L engines only. Check
adjustment at 15,000 mile intervals.
VALVE CLEARANCE SPECIFICATIONS - 1.5L
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Application ( 1) In. (mm)
Hot Engine
Intake ....................... .006 (.15)
Exhaust ...................... .010 (.25)
Cold Engine
Intake ....................... .003 (.07)
Exhaust ...................... .007 (.17)
( 1) - Adjust valves with engine hot.
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Page 741 of 1333
No. 3 Wire ....................... 12,000
No. 4 Wire ....................... 14,000
3.0L (VIN B & C)
Coil Wire ...................... Not Used
No. 1 Wire ......................... 8600
No. 2 Wire ....................... 13,900
No. 3 Wire ......................... 6400
No. 4 Wire ....................... 11,500
No. 5 Wire ......................... 4500
3.0L (VIN S)
Coil Wire .......................... 3000
No. 1 Wire ......................... 9000
No. 2 Wire ......................... 8500
No. 3 Wire ....................... 10,000
No. 4 Wire ......................... 9000
No. 5 Wire ....................... 12,000
No. 6 Wire ....................... 10,000
No. 6 Wire ....................... 11,700
(1) - See A - ENGINE/VIN ID article in the
ENGINE PERFORMANCE Section for VIN
information.
( 2) - Information not available from mfg.
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SPARK PLUGS
SPARK PLUG TYPE \
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Application Nippondenso No.
1.5L (VIN A) .................... W20EPR-11
1.6L (VIN Y) .................... W20EPR-11
1.8L (VIN T) .................... W20EPR-11
2.0L (VIN R) ....................... W20EPR
2.0L (VIN U & V) ................ W20EPR-11
2.4L (VIN W) .................... W20EPR-11
3.0L (VIN B & C) ............... PK20PR-P11
3.0L (VIN S) .................... W16EPR-11
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SPARK PLUG SPECIFICATIONS \
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Gap Torque
Application In. (mm) Ft. Lbs. (N.m\
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2.0L (VIN R & U) ....... .028-.031 (.7-.8) ......... 15-21 (20-\
30)
All Others ............ .039-.043 (1.0-1.1) ........ 15-21 (20-30\
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FIRING ORDER & TIMING MARKS
WARNING: On the 3.0L V6, the firing order and the spark plug
connection order on the top of the distributor do not match.
Circuits internal to the distributor cap differ from the
external spark plug wire connections. This is intentional and
is done to avoid spark plug wires crossover. See Fig. 3.
Page 1146 of 1333
motor to increase idle speed. To prevent A/C compressor from switching
on before idle speed has increased, ECU momentarily opens A/C relay
circuit.
Idle Speed Control (ISC) Motor
Controls pintle-type air valve (DOHC engines) or throttle
plate angle (SOHC engines) to regulate volume of intake air at idle.
During start mode, ECU controls idle intake air volume
according to coolant temperature input. After starting, with idle
position switch activated (throttle closed), fast idle speed is
controlled by ISC motor and fast idle air control valve (if equipped).\
When idle switch is deactivated (throttle open), ISC motor
moves to a preset position in accordance with coolant temperature
input.
When automatic transmission (if equipped) is shifted from
Neutral to Drive, A/C is turned on or power steering pressure reaches
a preset value, ECU signals ISC motor to increase engine RPM.
Fast Idle Air Control Valve
Some models use a coolant temperature-sensitive fast idle air
control valve, located on throttle body, to admit additional intake
air volume during engine warm-up. Control valve closes as temperature
increases, restricting by-pass airflow rate. At engine warm-up, valve
closes completely.
IGNITION SYSTEMS
DIRECT IGNITION SYSTEM (DIS) - DOHC ENGINES
Ignition system is a 2-coil, distributorless ignition system.
Crankshaft angle and TDC sensor assembly, mounted in place of
distributor, are optically controlled.
Power Transistors & Ignition Coils
Based on crankshaft angle and TDC sensor inputs, ECU controls
timing and directly activates each power transistor to fire coils.
Power transistor "A" controls primary current of ignition coil "A" to
fire spark plugs on cylinders No. 1 and 4 at the same time. Power
transistor "B" controls primary current of ignition coil "B" to fire
spark plugs on cylinders No. 2 and 3 at the same time.
Although each coil fires 2 plugs at the same time, ignition
takes place in only one cylinder since the other cylinder is on its
exhaust stroke when plug fires.
ELECTRONIC IGNITION SYSTEM - SOHC ENGINES
Mitsubishi breakerless electronic ignition system uses a disc
and optical sensing unit to trigger power transistor.
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. ECU 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 ECU. ECU adjusts timing
based upon various conditions, such as engine temperature, altitude
and detonation (turbo vehicles only).
Page 1205 of 1333
Incorrect ignition timing Reset ignition timing,
See TUNE-UP
Leaking valves Replace valves, See
ENGINES
Worn fuel pump diaphragm Replace diaphragm or
or piston piston
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Intake Backfire Improper ignition timing Reset ignition timing,
See TUNE-UP
Faulty accelerator pump Replace accelerator
discharge pump
Improper choke operation Check choke and adjust
as required
Defective EGR valve Replace EGR valve
Fuel mixture too lean Reset air/fuel mixture,
See TUNE-UP
Choke valve initial Reset choke valve
clearance too large initial clearance
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Exhaust Backfire Vacuum leak Inspect and repair
vacuum system
Faulty vacuum diverter Replace vacuum diverter
valve valve
Faulty choke operation Check choke and adjust
as required
Exhaust system leak repair exhaust system
leak
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Engine Ignition timing too far Reset ignition timing,
Detonation advanced See TUNE-UP
Faulty ignition system Check ignition timing,
See TUNE-UP
Spark plugs loose or Retighten or replace
faulty plugs
Fuel delivery system Inspect lines, pump and
clogged filter for clog
EGR valve inoperative Replace EGR valve
PCV system inoperative Inspect and/or replace
hoses or valve
Vacuum leaks Check vacuum system and
repair leaks
Excessive combustion
chamber deposits Remove built-up
deposits
Leaking, sticking or Inspect and/or replace
broken valves valves
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External Oil Fuel pump improperly seated Remove pump, replace
Leakage or worn gasket gasket and seat
properly
Oil pan gasket broken or Straighten pan and
pan bent replace gasket
Timing chain cover gasket Replace timing chain
broken cover gasket
Rear main oil seal worn Replace rear main oil
seal
Oil pan drain plug not Remove and reinstall
seated properly drain plug
Camshaft bearing drain Remove restriction
hole blocked
Oil pressure sending Remove and reinstall
switch leaking sending switch
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Excessive cylinder wear Rebore or replace
block
Excessive valve guide Worn or loose bearing
clearance
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Gap Bridged Deposits in combustion Clean combustion
chamber becoming fused chamber of deposits
to electrode
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Blistered Engine overheating Check cooling system
Electrode
Wrong type of fuel Replace with correct
fuel
Loose spark plugs Retighten spark plugs
Over-advanced ignition Reset ignition timing
timing see ENGINE PERFORMANCE
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Pre-Ignition or Incorrect type of fuel Replace with correct
Melted Electrodes fuel
Incorrect ignition timing Reset ignition timing
see ENGINE PERFORMANCE
Burned valves Replace valves
Engine Overheating Check cooling system
Wrong type of spark plug, Replace with correct
too hot spark plug, see
ENGINE PERFORMANCE
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Chipped Severe detonation Check for over-
Insulators advanced timing or
combustion
Improper gapping Re-gap spark plugs
procedure
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Rust Colored Additives in unleaded Try different fuel
Deposits fuel brand
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Water In Combus- Blown head gasket or Repair or replace
tion Chamber cracked head head or head gasket
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NOTE: Before diagnosing an electronic ignition system, ensure that
all wiring is connected properly between distributor, wiring
connector and spark plugs. Ignition problem will show up
either as: Engine Will Not Start or Engine Runs Rough.
BASIC ELECTRONIC IGNITION TROUBLE SHOOTING CHARTS
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CONDITION POSSIBLE CAUSE CORRECTION \
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Engine Won't Open circuit between Repair circuit
Start distributor and bulkhead
connector
Open circuit between Repair circuit
bulkhead connector and
Page 1224 of 1333
![MITSUBISHI MONTERO 1991 User Guide ignition switch
Open circuit between Repair circuit
ignition switch and
starter solenoid
\](/img/19/57332/w960_57332-1223.png "MITSUBISHI MONTERO 1991 User Guide ignition switch
Open circuit between Repair circuit
ignition switch and
starter solenoid
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ignition switch
Open circuit between Repair circuit
ignition switch and
starter solenoid
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Engine Runs Fuel lines leaking or Tighten fitting,
Rough clogged remove restriction
Initial timing incorrect Reset ignition timing
see ENGINE PERFORMANCE
Centrifugal advance Repair distributor
malfunction advance
Defective spark plugs or Replace plugs or plug
wiring wiring
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Component Failure Spark arc-over on cap, Replace cap, rotor or
rotor or coil or coil
Defective pick-up coil Replace pick-up coil
Defective ignition coil Replace ignition coil
Defective vacuum unit Replace vacuum unit
Defective control module Replace control module
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BASIC ELECTRONIC IGNITION TROUBLE SHOOTING
CHARTS - USING OSCILLOSCOPE PATTERNS
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CONDITION POSSIBLE CAUSE CORRECTION \
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Firing Voltage Retarded ignition timing Reset ignition
Lines are the Same, timing, see ENGINE
but Abnormally High PERFORMANCE section
Fuel mixture too lean Readjust carburetor,
see ENGINE PERFORMANCE
High resistance in coil Replace coil wire
wire
Corrosion in coil tower Clean and/or replace
terminal coil
Corrosion in distributor Clean and/or replace
coil terminal distributor cap
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Firing Voltage Fuel mixture too rich Readjust carburetor,
Lines are the Same see ENGINE PERFORMANCE
but Abnormally Low
Breaks in coil wire causing Replace coil wire
arcing
Cracked coil tower causing Replace coil
arcing
Low coil output Replace coil
Low engine compression Determine cause and
Page 1225 of 1333
![MITSUBISHI MONTERO 1991 User Guide repair \
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repair \
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One or More, But Carburetor idle mixture Readjust carburetor,
Not All Firing not balanced see ENGINE PERFORMANCE
Voltage Lines are
Higher Than Others EGR valve stuck open Clean and/or replace
valve
High resistance in spark Replace spark plug
plug wires wires
Cracked or broken spark Replace spark plugs
plug insulator
Intake vacuum leak Repair leak
Defective spark plugs Replace spark plugs
Corroded spark plug Replace spark plugs
terminals
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One or More, But Curb idle mixture not Readjust carburetor,
Not All Firing balanced see ENGINE PERFORMANCE
Voltage Lines Are
Lower Than Others Breaks in plug wires Replace plug wires
causing arcing
Cracked coil tower causing Replace coil
arcing
Low compression Determine cause and
repair
Defective spark plugs Replace spark plugs
Corroded spark plugs Replace spark plugs
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Cylinders Not Cracked distributor cap Replace distributor
Firing terminals cap
Shorted spark plug wire Determine cause and
repair
Mechanical problem in Determine cause and
engine repair
Defective spark plugs Replace spark plugs
Spark plugs fouled Replace spark plugs
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BASIC DRIVEABILITY PROBLEMS TROUBLE SHOOTING TABLE \
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CONDITION POSSIBLE CAUSE CORRECTION \
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Hard Starting Binding carburetor linkage Eliminate binding
Binding choke linkage Eliminate binding
Binding choke piston Eliminate binding
Restricted choke vacuum Check vacuum lines
for blockage
Page 1226 of 1333
Worn or dirty needle valve Clean carburetor, see
and seat ENGINE PERFORMANCE
Float sticking Readjust or replace
float see the ENGINE
PERFORMANCE section
Incorrect choke adjustment Reset choke adjustment
see ENGINE PERFORMANCE
Defective coil Replace coil
Improper spark plug gap Regap spark plugs
Incorrect ignition timing Reset ignition timing
see ENGINE PERFORMANCE
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Detonation Over-advanced ignition Reset ignition timing
timing see ENGINE PERFORMANCE
Defective spark plugs Replace spark plugs
Fuel lines clogged Clean fuel lines
EGR system malfunction Check and repair EGR
system
PCV system malfunction Repair PCV system
Vacuum leaks Check and repair
vacuum system
Loose fan belts Tighten or replace
fan belts, see ENGINE
PERFORMANCE
Restricted airflow Remove restriction
Vacuum advance malfunction Check distributor
operation
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Dieseling Binding carburetor linkage Eliminate binding
Binding throttle linkage Eliminate blinding
Binding choke linkage or Eliminate binding
fast idle cam
Defective idle solenoid Replace idle solenoid
see ENGINE PERFORMANCE
Improper base idle speed Reset idle speed, see
see ENGINE PERFORMANCE
Incorrect ignition timing Reset ignition timing
see ENGINE PERFORMANCE
Incorrect idle mixture Reset idle mixture,
setting see ENGINE PERFORMANCE
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Faulty Incorrect ignition timing Reset ignition timing
Acceleration see ENGINE PERFORMANCE