check engine MITSUBISHI MONTERO 1991 Service Manual
[x] Cancel search | Manufacturer: MITSUBISHI, Model Year: 1991, Model line: MONTERO, Model: MITSUBISHI MONTERO 1991Pages: 1333, PDF Size: 24.61 MB
Page 1220 of 1333
connections for
tight and clean
connections
Ignition switch faulty Adjust or replace
or misadjusted ignition switch as
necessary
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Starter Cranks Battery weak or Charge or replace
Engine Slowly defective battery as necessary
Engine overheated See ENGINE COOLING
SYSTEM article
Engine oil too heavy Check that proper
viscosity oil
is used
Poor battery-to-starter Check that all
connections between
battery and starter are
clean and tight
Current draw too low or See Bench Tests in
too high STARTER article
Bent armature, loose pole See STARTER article
shoes screws or worn
bearings
Burned solenoid contacts Replace solenoid
Faulty starter Replace starter
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Starter Engages Engine timing too far See Ignition Timing in
Engine Only advanced TUNE-UP article
Momentarily
Overrunning clutch not Replace overrunning
engaging properly clutch. See STARTER
article
Broken starter clutch See STARTER article
Broken teeth on engine Replace flywheel and
flywheel check starter pinion
gear for damage
Weak drive assembly See STARTER article
thrust spring
Weak hold-in coil See Bench Tests in
STARTER article
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Starter Drive Defective point assembly See Testing in STARTER
Will Not Engage article
Poor point assembly ground See Testing in STARTER
article
Defective pull-in coil Replace starter
solenoid
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Starter Relay Dead battery Charge or replace
Page 1221 of 1333
Does Not Close battery as necessary
Faulty wiring Check all wiring and
connections leading to
relay
Neutral safety switch Replace neutral safety
faulty switch
Starter relay faulty Replace starter relay
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Starter Drive Starter motor loose on Tighten starter
Will Not mountings attach bolts
Disengage
Worn drive end bushing See STARTER article
Damaged engine flywheel Replace flywheel and
teeth starter pinion gear for
damage
Drive yolk return spring Replace return spring
broken or missing
Faulty ignition switch Replace ignition switch
Insufficient clearance Replace starter
between winding leads to solenoid
solenoid terminal and main
contact in solenoid
Starter clutch not Replace starter clutch
disengaging
Ignition starter switch Replace ignition switch
contacts sticking
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Starter Relay Faulty solenoid switch, Check all wiring
Operates but switch connections or between relay and
Solenoid Does Not solenoid or replace
relay or solenoid as
necessary
Broken lead or loose Repair wire or wire
soldered connections connections as
necessary
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Solenoid Plunger Weak battery Charge or replace
Vibrates When battery as necessary
Switch is Engaged
Solenoid contacts Clean contacts or
corroded replace solenoid
Faulty wiring Check all wiring
leading to solenoid
Broken connections inside Repair connections or
switch cover replace solenoid
Open hold-in wire Replace solenoid
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Low Current Draw Worn brushes or weak Replace brushes or
brush springs as
necessary
Page 1222 of 1333
![MITSUBISHI MONTERO 1991 Service Manual \
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High Pitched Whine Distance too great")
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High Pitched Whine Distance too great Align starter or check
During Cranking between starter that correct starter
Before Engine pinion and flywheel and flywheel are being
Fires but Engine used
Fires and Cranks
Normally
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High Pitched Distance too small between
Whine After Engine starter pinion and flywheel
Fires With Key Flywheel runout contributes
released. Engine to the intermittent nature
Fires and Cranks
Normally
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TUNE-UP TROUBLE SHOOTING - GAS ENGINE VEHICLES
NOTE: This is GENERAL information. This article is not intended
to be specific to any unique situation or individual vehicle
configuration. The purpose of this Trouble Shooting
information is to provide a list of common causes to
problem symptoms. For model-specific Trouble Shooting,
refer to SUBJECT, DIAGNOSTIC, or TESTING articles available
in the section(s) you are accessing.
BASIC SPARK PLUG TROUBLE SHOOTING CHARTS
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CONDITION POSSIBLE CAUSE CORRECTION \
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Normal Spark Light Tan or Gray deposits No Action
Plug Condition
Electrode not burned or No Action
fouled
Gap tolerance not changed No Action
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Cold Fouling or Overrich air/fuel mixture Adjust air/fuel
Carbon Deposits mixture, see ENGINE
PERFORMANCE section
Faulty choke Replace choke
assembly, see ENGINE
PERFORMANCE section
Clogged air filter Clean and/or replace
air filter
Incorrect idle speed or Reset idle speed and/
dirty carburetor or clean carburetor
Faulty ignition wires Replace ignition
wiring
Prolonged operation Shut engine off
at idle during long idle
Sticking valves or worn Check valve train
valve guide seals
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Wet Fouling Worn rings and pistons Install new rings and
or Oil Deposits pistons
Page 1223 of 1333
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 1225 of 1333
![MITSUBISHI MONTERO 1991 Service Manual 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
Page 1227 of 1333
Engine cold and choke too Adjust choke and
lean allow engine to warm-
up
Defective spark plugs Replace spark plugs
Defective coil Replace coil
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Faulty Low Speed Clogged idle transfer slots Clean idle transfer
Operation slots, see FUEL
Restricted idle air bleeds Disassemble and clean
and passages carburetor, see FUEL
Clogged air cleaner Replace air filter
Defective spark plugs Replace spark plugs
Defective ignition wires Replace ignition wire
see ENGINE PERFORMANCE
Defective distributor cap Replace distributor
cap
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Faulty High Speed Incorrect ignition timing Reset ignition timing
Operation see ENGINE PERFORMANCE
Defective distributor Replace advance
centrifugal advance mechanism
Defective distributor Replace advance unit
vacuum advance
Incorrect spark plugs or Check gap and/or
plug gap replace spark plugs
Faulty choke operation Check choke and
repair as required
Clogged vacuum passages Remove restrictions
Improper size or clogged Check jet size and
main jet clean, see FUEL
Restricted air cleaner Check filter and
replace as necessary
Defective distributor cap, Replace cap, rotor or
rotor or coil coil
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Misfire at All Defective spark plugs Replace spark plugs
Speeds
Defective spark plug wires Replace spark plug
wires
Defective distributor cap, Replace cap, rotor,
rotor, or coil or coil
Cracked or broken vacuum Replace vacuum hoses
hoses
Page 1228 of 1333
![MITSUBISHI MONTERO 1991 Service Manual Vacuum leaks Repair vacuum leaks
Fuel lines clogged Remove restriction
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Fuel lines clogged Remove restriction
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Vacuum leaks Repair vacuum leaks
Fuel lines clogged Remove restriction
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Hesitation Cracked or broken vacuum Replace vacuum hoses
hoses
Vacuum leaks Repair Vacuum leaks
Binding carburetor linkage Eliminate binding
Binding throttle linkage Eliminate binding
Binding choke linkage or Eliminate binding
fast idle cam
Improper float setting Readjust float
setting, see FUEL
Cracked or broken ignition Replace ignition
wires wires
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Rough idle, Incorrect curb idle or fast Reset idle speed, see
Missing or idle speed see ENGINE PERFORMANCE
Stalling
Incorrect basic timing Reset ignition timing
see ENGINE PERFORMANCE
Improper idle mixture Reset idle mixture,
adjustment see ENGINE PERFORMANCE
Improper feedback system Check feedback system
operation see ENGINE PERFORMANCE
Incorrect spark plug gap Reset spark plug gap,
see ENGINE PERFORMANCE
Moisture in ignition Dry components
components
Loose or broken ignition Replace ignition
wires wires
Damaged distributor cap or Replace distributor
or rotor cap or rotor
Faulty ignition coil Replace ignition coil
Fuel filter clogged or worn Replace fuel filter
Damaged idle mixture screw Replace idle mixture
screw, see FUEL
Improper fast idle cam Reset fast idle cam
adjustment adjustment, see TUNE-
see ENGINE PERFORMANCE
Improper EGR valve operation Replace EGR valve
Faulty PCV valve air flow Replace PCV valve
Choke binding or improper Reset choke or
choke setting eliminate binding
Page 1229 of 1333
Vacuum leak Repair vacuum leak
Improper float bowl fuel Reset float
level adjustment, see FUEL
Clogged air bleed or idle Clean carburetor
passages passages, see FUEL
Clogged or worn air cleaner Replace air filter
filter
Faulty choke vacuum Replace diaphragm,
diaphragm see ENGINE PERFORMANCE
Exhaust manifold heat valve Replace heat valve
inoperative
Improper distributor spark Check distributor
advance operation
Leaking valves or valve Check and repair
components valvetrain
Improper carburetor Remove and remount
mounting carburetor
Excessive play in Replace distributor
distributor shaft
Loose or corroded wiring Repair or replace as
connections required
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Engine Surges Improper PCV valve airflow Replace PCV valve
Vacuum leaks Repair vacuum leaks
Clogged air bleeds Remove restriction
EGR valve malfunction Replace EGR valve
Restricted air cleaner Replace air filter
filter
Cracked or broken vacuum Replace vacuum hoses
hoses
Cracked or broken ignition Replace ignition
wires wires
Vacuum advance malfunction Check unit and
replace as necessary
Defective or fouled spark Replace spark plugs
plugs
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Ping or Spark Incorrect ignition timing Reset ignition timing
Knock see ENGINE PERFORMANCE
Distributor centrifugal or Check operation and
vacuum advance malfunction replace as necessary
Carburetor setting too lean Readjust mixture
Page 1241 of 1333
![MITSUBISHI MONTERO 1991 Service Manual Brakes dragging See BRAKES article \
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Brakes dragging See BRAKES article \
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Instability Low or uneven tire Inflate to proper
pressure pressure
Loose or worn wheel See FRONT SUSPENSION
bearings article
Loose or worn idler arm See FRONT SUSPENSION
bushing article
Loose or worn strut See FRONT SUSPENSION
bushings article
Incorrect front wheel See WHEEL ALIGNMENT
alignment article
Steering gear not See MANUAL STEERING
centered GEARS article
Springs or shock Check and replace if
necessary
Improper cross shaft See MANUAL STEERING
GEARS article
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POWER STEERING TROUBLE SHOOTING
NOTE: This is GENERAL information. This article is not intended
to be specific to any unique situation or individual vehicle
configuration. The purpose of this Trouble Shooting
information is to provide a list of common causes to
problem symptoms. For model-specific Trouble Shooting,
refer to SUBJECT, DIAGNOSTIC, or TESTING articles available
in the section(s) you are accessing.
BASIC POWER STEERING TROUBLE SHOOTING CHART
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CONDITION POSSIBLE CAUSE CORRECTION \
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Rattle or Pressure hoses touching Adjust to proper
Chucking Noise engine parts clearance
Loose Pitman shaft Adjust or replace if
necessary
Tie rods ends or Pitman Tighten and check system
arm loose
Rack and pinion mounts Tighten all mounting
loose bolts
Free play in worm and See POWER STEERING GEAR
article
Loose sector shaft or See POWER STEERING GEAR
thrust bearing adjustment
Free play in pot coupling See STEERING COLUMN
article