engine oil 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 1224 of 1333
![MITSUBISHI MONTERO 1991 Service Manual ignition switch
Open circuit between Repair circuit
ignition switch and
starter solenoid
\](/img/19/57332/w960_57332-1223.png "MITSUBISHI MONTERO 1991 Service Manual 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 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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\](/img/19/57332/w960_57332-1227.png "MITSUBISHI MONTERO 1991 Service Manual Vacuum leaks Repair vacuum leaks
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 1231 of 1333
Excessive Noise Loose pump-to-drive Tighten screws
assembly screws
Loose tube on pump assembly Tighten tube
Valves not functioning Replace valves
properly
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Oil Leakage Loose end plug Tighten end plug
Bad seal crimp Remove and re-crimp
seal
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MANUAL TRANSMISSION
MANUAL TRANSMISSION 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.
MANUAL TRANSMISSION/TRANSAXLE TROUBLE SHOOTING
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Condition Possible Cause \
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Noisy In Forward Gears .Low gear oil level,
.Loose bell housing bolts,
.Worn bearings or gears
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Clunk On Deceleration
(FWD Only) .Loose engine mounts,
.Worn inboard CV joints,
.Worn differential pinion shaft,
.Side gear hub counterbore
in case worn oversize
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Gear Clash When Shifting
Forward Gears .Clutch Out Of Adjustment,
.Shift linkage damaged or
out of adjustment,
.Gears or synchronizers damaged,
.Low gear oil level
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Transmission Noisy When
Moving (RWD Only) Quiet In
Neutral With Clutch Engaged .Worn rear outputshaft bearing
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Gear Rattle .Worn bearings,
.Wrong gear oil,
.Low gear oil,
.Worn gears
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Steady Ticking At Idle
(Increases With RPM) .Broken tooth on gear
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Gear Clash When Shifting
Forward Gears .Worn or broken synchronizers
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Loud Whine In Reverse .Normal condition ( 1) \
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Page 1233 of 1333
![MITSUBISHI MONTERO 1991 Service Manual \
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CONDITION POSSIBLE CAUSE](/img/19/57332/w960_57332-1232.png "MITSUBISHI MONTERO 1991 Service Manual \
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CONDITION POSSIBLE CAUSE")
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CONDITION POSSIBLE CAUSE CORRECTION \
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Chattering or Incorrect clutch adjustment Adjust clutch
Grabbing
Oil, grease or glaze on Disassemble and clean
facings or replace
Loose "U" joint flange See DRIVE AXLES
article
Worn input shaft spline Replace input shaft
Binding pressure plate Replace pressure plate
Binding release lever See CLUTCH article
Binding clutch disc hub Replace clutch disc
Unequal pressure plate Replace worn/misaligned
contact components
Loose/bent clutch disc Replace clutch disc
Incorrect transmission Realign transmission
alignment
Worn pressure plate, disc Replace damaged
or flywheel components
Broken or weak pressure Replace pressure
springs plate
Sticking clutch pedal Lubricate clutch pedal
& linkage
Incorrect clutch disc Replace clutch disc
facing
Engine loose in chassis Tighten all mounting
bolts
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Failure to Oil or grease on clutch Clean or replace clutch
Release facings clutch disc
Incorrect release lever or See CLUTCH article
pedal adjustment
Worn or broken clutch Replace clutch disc
facings
Bent clutch disc or Replace damaged
pressure plate components
Clutch disc hub binding on Clean or replace clutch
input shaft disc and/or input shaft
Binding pilot bearing Replace pilot bearing
Sticking release bearing Replace release bearing
sleeve and/or sleeve
Binding clutch cable See CLUTCH article
Page 1235 of 1333
Dry or binding clutch Lubricate and align
pedal hub components
Floor mat interference Lay mat flat in proper
with pedal area
Dry or binding ball/fork Lubricate and align
pivots components
Faulty clutch cable Replace clutch cable
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Noisy Clutch Faulty interlock switch Replace interlock
Pedal switch
Self-adjuster ratchet Lubricate or replace
noise self-adjuster
Speed control interlock Lubricate or replace
switch interlock switch
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Clutch Pedal Binding clutch cable See CLUTCH article
Sticks Down
Springs weak in pressure Replace pressure plate
plate
Binding in clutch linkage Lubricate and free
linkage
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Noisy Dry release bearing Lubricate or replace
release bearing
Dry or worn pilot bearing Lubricate or replace
bearing
Worn input shaft bearing Replace bearing
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Transmission Weak springs in pressure Replace pressure plate
Click plate
Release fork loose on ball Replace release fork
stud and/or ball stud
Oil on clutch disc damper Replace clutch disc
Broken spring in slave Replace slave cylinder
cylinder
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DRIVE AXLE - NOISE DIAGNOSIS
Unrelated Noises
Some driveline trouble symptoms are also common to the
engine, transmission, wheel bearings, tires, and other parts of the
vehicle. Ensure cause of trouble actually is in the drive axle before
adjusting, repairing, or replacing any of its parts.
Non-Drive Axle Noises
A few conditions can sound just like drive axle noise and
have to be considered in pre-diagnosis. The 4 most common noises are
exhaust, tires, CV/universal joints and wheel trim rings.
Page 1244 of 1333
Reaction ring sticking See POWER STEERING GEAR
in housing head article
Steering pump internal See POWER STEERING PUMP
leakage article
Steering gear-to-column See STEERING COLUMN
misalignment article
Lack of lubrication in Service front suspension
linkage
Lack of lubrication in Service front suspension
ball joints
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Increased Effort High internal pump leakage See POWER STEERING PUMP
When Turning article
Wheel Fast Power steering pump belt Adjust or replace if
Foaming, Milky slipping necessary
Power Steering
Fluid, Low Fluid Low fluid level Check and fill to
Level or Low proper level
Pressure
Engine idle speed to low Adjust to correct
setting
Air in pump fluid system See POWER STEERING PUMP
article
Pump output low See POWER STEERING PUMP
article
Steering gear See POWER STEERING GEAR
malfunctioning article
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Wheel Surges Low fluid level Check and fill to proper
or Jerks level
Loose fan belt Adjust or replace if
necessary
Insufficient pump See POWER STEERING PUMP
pressure article
Sticky flow control valve See POWER STEERING PUMP
article
Linkage hitting oil pan Replace bent components
at full turn
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Kick Back or Air in pump fluid system See POWER STEERING PUMP
Free Play article
Worn poppet valve in See POWER STEERING PUMP
steering gear article
Excessive over center See POWER STEERING GEAR
lash article
Thrust bearing out of See POWER STEERING GEAR
adjustment article
Page 1273 of 1333
3800 engines were suffering from exactly this. The point is that a
lack of detail could cause misdiagnosis.
As you might have guessed, a lab scope would not miss this.
RELATIONSHIP BETWEEN DWELL & DUTY CYCLE READINGS TABLE (1)
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Dwell Meter (2) Duty Cycle Meter
1
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15 .................................................. 25%
30 .................................................. 50%
45 .................................................. 75%
60 ................................................. 100%
( 1) - These are just some examples for your understanding.
It is okay to fill in the gaps.
( 2) - Dwell meter on the six-cylinder scale.
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THE TWO TYPES OF INJECTOR DRIVERS
OVERVIEW
There are two types of transistor driver circuits used to
operate electric fuel injectors: voltage controlled and current
controlled. The voltage controlled type is sometimes called a
"saturated switch" driver, while the current controlled type is
sometimes known as a "peak and hold" driver.
The basic difference between the two is the total resistance
of the injector circuit. Roughly speaking, if a particular leg in an
injector circuit has total resistance of 12 or more ohms, a voltage
control driver is used. If less than 12 ohms, a current control driver
is used.
It is a question of what is going to do the job of limiting
the current flow in the injector circuit; the inherent "high"
resistance in the injector circuit, or the transistor driver. Without
some form of control, the current flow through the injector would
cause the solenoid coil to overheat and result in a damaged injector.
VOLTAGE CONTROLLED CIRCUIT ("SATURATED SWITCH")
The voltage controlled driver inside the computer operates
much like a simple switch because it does not need to worry about
limiting current flow. Recall, this driver typically requires injector
circuits with a total leg resistance of 12 or more ohms.
The driver is either ON, closing/completing the circuit
(eliminating the voltage-drop), or OFF, opening the circuit (causing \
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total voltage drop).
Some manufacturers call it a "saturated switch" driver. This
is because when switched ON, the driver allows the magnetic field in
the injector to build to saturation. This is the same "saturation"
property that you are familiar with for an ignition coil.
There are two ways "high" resistance can be built into an
injector circuit to limit current flow. One method uses an external
solenoid resistor and a low resistance injector, while the other uses
a high resistance injector without the solenoid resistor. See the left
side of Fig. 1.
In terms of injection opening time, the external resistor
voltage controlled circuit is somewhat faster than the voltage
controlled high resistance injector circuit. The trend, however, seems
to be moving toward use of this latter type of circuit due to its
lower cost and reliability. The ECU can compensate for slower opening