oil temperature ISUZU TROOPER 1995 Workshop Manual

FLUID LEVEL CHECK
A fluid loss in any system (except windshield
washer) may indicate a problem. Repair the system
at once.
Engine
oil level -Check level and add if
necessary. The best time to check the engine oil
level is
when the oil is warm. After stopping the
engine with the vehicle on a level surface, wait a
few minutes for the oil to drain back to the oil pan.
Pull
out the oil level indicator (dipstick). Wipe it
clean and push the oil level indicator back down all
the
way. Pull out the oil level indicator, keeping the
tip down, and look at the oil level on it.
Add oil, if needed, to keep the oil level above
the
"ADD" mark and between the "ADD" and
"FULL" marks in the operating range area. Avoid
overfilling the engine since this may cause engine
damage. Push
the oil level indicator back down all
the
way after taking the reading.
If you check the oil level when the oil is cold, do
not run the engine first. The cold oil will not drain
back
to the pan fast enough to give a true oil level.
Engine coolant level and condition -Check
engine coolant level in the coolant reservoir and
add engine
coolant if necessary. Inspect the engine
coolant and replace it if dirty or rusty.
Windshield washer fluid level -Check washer
fluid level in reservoir and add if necessary.
Power steering system reservoir level-Check
and keep at
proper level.
Brake master cylinder reservoir level -Check
fluid. Keep fluid at proper level. A low fluid level
can indicate
worn disc brake pads which may need
to be serviced.
Hydraulic clutch system -Check fluid l~vel in
the reservoir.
Add fluid as required.
Battery fluid level -Check fluid level in the
battery.
FLUID LEAK CHECK
Check for fuel, water, oil or other fluid leaks by
looking at the surface beneath the vehicle after it
has been parked for a while. Water dripping from
the air conditioning system after use is normal. If
you notice gasoline fumes or fluid at any time,
locate the source and correct it at once.
ENGINE OIL AND OIL FILTER
REPLACEMENT
Always use API SE, SF, SG, SH or ILSAC GF-1
quality oils of the proper viscosity.
When choosing an oil, consider the range of
temperatures the car will be operated in before the
next oil change. Then, select the recommended oil
viscosity
from the chart (Fig. OB-1).
Always change the oil and the oil filter as soon as
possible after driving in a dust storm.
MAINTENANCE AND LUBRICATION OB-5
ENGINE COOLING SYSTEM INSPECTION
Inspect coolant/anti-freeze. If coolant is dirty or
rusty, drain, flush and refill with new coolant. Keep
coolant at the proper mixture for proper freeze
protection,
corrosion inhibitor level and best engine
operating temperature.
Inspect hoses and replace if
cracked, swollen or deteriorated. Tighten hose
clamps if equipped with screw-type clamps. Clean
outside of radiator and air conditioning condenser.
Wash
filler cap and neck. To help ensure proper
operation, a pressure test of both the cooling
system and cap is also recommended.
EXHAUST SYSTEM INSPECTION
Visually inspect the exhaust pipes, muffler, heat
shields and hangers
for cracks, deterioration, or
damage.
Be alert to any changes in the sound of the exhaust
system
or any smell of fumes. These are signs the
system may be leaking or overheating. Repair the
system at once,
if these conditions exist. (See also
"Engine Exhaust Gas Safety" and "Three Way
Catalytic Converter" in Owner's manual.)
FUEL CAP, FUEL LINES, AND FUEL TANK
INSPECTION
Inspect the fuel tank, the fuel cap and the fuel lines
every
60,000 miles (96,000 km) for damage which
could cause leakage.
Inspect the fuel cap and the gasket for correct sealing
and physical damage. Replace any damaged parts.
DRIVE BELT INSPECTION
Check the belts driving the steering oil pump, the air
conditioning compressor, and the generator
for
cracks, fraying, wear, and correct tension every 30,000
miles (48,000 km). Adjust or replace as necessary.
WHEEL ALIGNMENT, BALANCE AND
TIRES OPERATION
Uneven or abnormal tire wear, or a pull right or left
on a straight and level road may show the need for
a wheel alignment. A vibration of the steering
wheel or seat at normal highway speeds means a
wheel balancing is needed. Check tire pressure
when the tires are "cold" (include the spare).
Maintain pressure as shown in the tire placard,
which is located on the driver's door lock pillar.
STEERING SYSTEM OPERATION
Be alert for any changes in steering action. An
inspection
or service is needed when the steering
wheel is harder
to turn or has too much free play, or
if there are unusual sounds when turning or parking.

MAINTENANCE AND LUBRICATION 08-9
LUBRICANT VISCOSITY CHART
Lubricants should be carefully selected according to the lubrication chart. It is also important to select viscosity of
lubricants according to the ambient temperature by referring to the following table.
OIL VISCOSITY CHART FOR GASOLINE ENGINE
(Single grade) VISCOSITY GRADE -AMBIENT TEMPERATURE
Fig.
OB-1
OIL VISCOSITY CHART FOR MANUAL TRANSMISSION AND TRANSFER CASE
(Single grade)
Fig.
08-2

The refrigeration cycle includes the following four
processes as the refrigerant changes repeatedly
from liquid to gas and back to liquid while circulat­
ing.
EVAPORATION
The refrigerant is changed from a liquid to a gas in­
side
the evaporator. The refrigerant mist that enters
the evaporator vaporizes readily. The liquid refrige­
rant removes
the required quantity of heat (latent
heat of vaporization) from the air around the evap­
orator core cooling fins and rapidly vaporizes.
Removing the heat cools the air, which is then
radiated
from the fins and lowers the temperature of
the air inside the vehicle.
The refrigerant liquid sent from the expansion valve
and the vaporized refrigerant gas are both present
inside the
evaporator and the liquid is converted to
gas.
With this change from liquid to gas, the pressure
inside
the evaporator must be kept low enough for
vaporization to occur at a lower temperature.
Because of that, the vaporized refrigerant is sucked
into the compressor.
COMPRESSION
The refrigerant is compressed by the compressor
until it is easily liquefied at normal temperature.
The vaporized
refrigerant in the evaporator is sucked
into the compressor. This action maintains the
refrigerant inside the evaporator at a low pressure
so
that it can easily vaporize, even at low tempera­
tures close to ooc (32°F).
Also, the refrigerant sucked into the compressor is
compressed inside the
cylinder to increase the
pressure and temperature to values such that the
refrigerant can easily liquefy at normal ambient
temperatures.
CONDENSATION
The refrigerant inside the condenser is cooled by the
outside air and changes from gas to liquid.
The high temperature, high pressure gas coming
from the compressor is cooled and liquefied by the
condenser with outside air and accumulated in the
receiver/drier. The heat radiated to the outside air by
the high temperature, high pressure gas in the
compressor is called heat of condensation. This is
the total quantity of heat (heat of vaporization) the
refrigerant removes
from the vehicle interior via the
evaporator and the work (calculated as the quantity
of heat) performed for compression.
'-' EXPANSION
The expansion valve lowers the pressure of the
refrigerant liquid so that it can easily vaporize.
AIR CONDITIONING 1 B -3
The process of lowering the pressure to encourage
vaporization before the
liquefied refrigerant is sent
to the evaporator is called expansion. In addition,
the expansion valve controls the flow rate of the
refrigerant liquid while decreasing the pressure.
That is, the quantity of refrigerant liquid vaporized
inside
the evaporator is determined by the quantity
of heat which must be removed at a prescribed
vaporization temperature.
It is important that the
quantity of refrigerant be controlled to exactly the
right value.
COMPRESSOR
It compressor performs two main functions:
It compresses low-pressure and low-temperature
refrigerant vapor from the evaporator into high­
pressure and high-temperature
refrigerant vapor to
the condenser. And it pumps refrigerant and
refrigerant
oil through the air conditioning system.
This vehicle is equipped with five-vane rotary com­
pressor.
The
thermo sensor is installed to the front head of
the compressor to protect it by stopping its
operation when the refrigerant gas is insufficient or
when the temperature is abnormally high.
• OFF ...... 160 ±soc (320.0 ± 9.0°F)
• ON
...... 135 ±soc (27S.O ± 9.0°F)
The specified amount of the compressor oil is 1SOcc
(S.O fl.oz.).
The oil used in the HFC-134a system compressor
differs from that used in R-12 systems.
Also, compressor oil to be used varies according to
the compressor model. Be sure to avoid mixing two
or more different types of oil.
If the wrong oil is used, lubrication will be poor and
the compressor will seize or malfunction.
The magnetic clutch connector is a waterproof
type.
MAGNETIC CLUTCH
The compressor is driven by the drive belt from the
crank
pulley of the engine. If the compressor is ac­
tivated each
time the engine is started, this causes
too much load to the engine. The magnetic clutch
transmits the power from the engine to the com­
pressor and activates it when the air conditioning is
"ON". Also, it cuts off the power from the engine to
the compressor when the air conditioning is "OFF".
(Magnetic clutch repair procedure can be found in
Section 1 D.)

DIAGNOSIS
AIR CONDITIONING CYCLE DIAGNOSIS
TROUBLE POSSIBLE CAUSE
No cooling or 1. Magnetic clutch does not run
insufficient cooling
2. Compressor is not rotating properly
• Drive belt loosened or broken
• Magnetic clutch face is not
clean and slips
• Incorrect clearance between
magnetic
drive plate and pulley
• Compressor oil leaks from shaft
seal
or shell
• Compressor seized
3. Insufficient or excessive charge of
refrigerant
4. Leaks in the refrigerant system
5. Condenser clogged or insufficient
radiation
6. Temperature control link unit of the
heater
unit defective
7. Unsteady operation due to foreign
substance in expansion valve
8. Poor operation of electronic
thermostat
Insufficient velocity 1. Evaporator clogged or frosted
of cooling air
2. Air leaking from cooling unit or air
duct
3. Blower motor does not rotate prop-
erly
AIR CONDITIONING 1 B - 9
CORRECTION
• Refer to "MAGNETIC CLUTCH
• DIAGNOSIS" in this section
• Adjust the drive belt to the specified
tension
or replace the drive belt
• Clean the magnetic clutch face or
replace
• Adjust the clearance (Refer to Sec-
• tion 1 D "COMPRESSOR OVER-
HAUL")
• Replace the compressor
• Replace the compressor
• Discharge and recover refrigerant.
Recharge
to specified amount.
• Check refrigerant system for leaks
and repair
as necessary
Discharge and recover refrigerant.
Recharge
to specified amount.
• Clean the condenser or replace as
necessary
• Repair the link unit
• Replace the expansion valve
• Check electronic thermostat and
replace
as necessary
• Check evaporator core and replace
or clean the core
• Check evaporator and duct connec-
tion, then repair as necessary
• Refer to Section 1A for "FAN CON-
TROL KNOB
(FAN SWITCH) DIAG-
NOSIS"
* For the execution of the charging and discharging operation in the table above, refer to the "RECOVERY,
RECYCLING, EVACUATING
AND CHARGING" in this section.

1 B -20 AIR CONDITIONING
OK NG NG
0 X X
ffB-mEt
0-ring
Raised portion
Fig. 18-17
0
Fig. 18-18
Leak at Refrigerant Line Connections
1. Check the torque on the refrigerant line fitting
and, if too loose, tighten to the specified torque.
• Use two wrenches to prevent twisting and
damage to the line.
•
Do not over tighten.
2. Perform a leak test on the refrigerant line fitting.
3. If the leak is still present, discharge and recover
the refrigerant from the system.
4. Replace the 0-rings.
• 0-rings cannot be reused. Always replace
with new ones.
• Be sure to apply specified compressor oil to
the new 0-rings.
5. Retighten the refrigerant line fitting to the spe­
cified torque.
• Use two wrenches to prevent twisting and
damage to the line.
6. Evacuate, charge and retest the system.
Leaks in the Hose
If the compressor inlet or outlet hose is leaking, the
entire hose must be replaced. Refrigerant hose must
not be cut or spliced for repair.
1.
2.
3.
4.
5.
Locate the leak.
Discharge and recover the refrigerant.
Remove
the hose assembly.
• Cap the open connections at once.
Connect
the new hose assembly.
•
Use two wrenches to prevent twisting or
damage to the hose fitting.
• Tighten the hose fitting to the specified
torque.
Evacuate, charge and test the system.
Compressor Leaks
If leaks are located around the compressor shaft seal
or shell, replace or repair the compressor.
Recovery, Recycling, Evacuation and Charging
Handling HFC-134a:
Air conditioning systems contain HFC-134a.
This is a chemical mixture which requires special
handling procedures to avoid personal injury.
• Always wear safety goggles and protective
gloves.
•
Always work in a well-ventilated area. Do not
weld or steam clean on or near any vehicle­
installed air conditioning lines or components.
• If HFC-134a should come in contact with any part
of the body, flush the exposed area with cold
water and immediately seek medical help.
•
If it is necessary to transport or carry any
container of HFC-134a in a vehicle, do not carry it
in the passenger compartment.
• If it is necessary to fill a small HFC-134a container
from a large one, never fill the container com­
pletely. Space should always be allowed above
the liquid for expansion.
• HFC-134a and R-12 should never be mixed as their
compositions are not the same.
• HFC-134a PAG oil tends to absorb moisture more
quickly than R-12 mineral oil and, therefore,
should be handled more carefully.
•
Keep HFC-134a containers stored below 40°C
(100°F).
WARNING: • SHOULD
HFC-134a CONTACT YOUR EYE(S),
CONSULT
A DOCTOR IMMEDIATELY.
•
DO NOT RUB THE AFFECTED EYE(S). INSTEAD,
SPLASH QUANTITIES
OF FRESH COLD WATER
OVER THE AFFECTED AREA TO GRADUALLY
RAISE THE TEMPERATURE OF THE RE­
FRIGERANT ABOVE THE FREEZING POINT.
• OBTAIN
PROPER MEDICAL TREATMENT AS
SOON
AS POSSIBLE. SHOULD THE HFC-134a
TOUCH THE SKIN, THE INJURY MUST BE
TREATED THE SAME AS SKIN WHICH HAS BEEN
FROSTBITTEN OR FROZEN.

COMPRESSOR OVERHAUL 1 D - 1
SECTION 10
COMPRESSOR OVERHAUL
CONTENTS
General Description . . . . . . . . . . . . . . . . . . . . . 1 D-1
Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
D-2
General Information . . . . . . . . . . . . . . . . . . . . 1 D-3
Compressor Oil . . . . . . . . . . . . . . . . . . . . . . 1 D-3
Service Procedures . . . . . . . . . . . . . . . . . . . . . 1D-5
Magnetic Clutch Assembly . . . . . . . . . . . . . 1 D-5
Main Data and Specifications . . . . . . . . . . . . . 1 D-8
General Specifications . . . . . . . . . . . . . . . . . 1 D-8
Torque Specifications . . . . . . . . . . . . . . . . . 1 D-8
Special Tools . . . . . . . . . . . . . . . . . . . . . . . . . . 1D-9
GENERAL DESCRIPTION
When servicing the compressor, keep dirt or foreign
material from getting on or into the compressor
parts and system. Clean tools and a clean work area
are
important for proper service. The compressor
connections and the outside of the compressor
should be cleaned before any "On-Vehicle" repair,
or before removal of the compressor. The parts must
be kept clean at all times and any parts to be
reassembled
should be cleaned with Trichloro­
ethane, naphtha, kerosene, or equivalent solvent,
and
dried with dry air. Use only lint free cloths to
wipe parts.
The
operations described below are based on bench
overhaul
with compressor removed from the
vehicle, except as noted. They have been prepared
in
order of accessibility of the components. When
the compressor is removed from the vehicle for
servicing, the oil remaining in the compressor
should be discarded and new compressor oil added
to the compressor.
Magnetic clutch assembly repair procedures require
that the system be discharged of refrigerant. (Refer
to Section 1 B for "REFRIGERANT RECOVERY".)
Compressor malfunction will appear in one of four
ways: noise, seizure, leakage or low discharge
pressure. Resonant
compressor noises are not
cause for alarm; however, irregular noise or rattles
may indicate broken parts or excessive clearances
due to wear. To check seizure, de-energize the
magnetic clutch and check to see if the drive plate
can be rotated.
If rotation is impossible, the com­
pressor is seized. Low discharge pressure may be
due to a faulty internal seal of the compressor, or a
restriction in the compressor.
Low discharge pres­
sure
may also be due to an insufficient refrigerant
charge
or a restriction elsewhere in the system.
These possibilities
should be checked prior to
servicing the compressor. If the compressor is
inoperative,
but is not seized, check to see if current
is being supplied to the magnetic clutch coil
terminals.
This vehicle is equipped with five-vane rotary com­
pressor.
The
compressor has vanes built into a rotor which is
mounted on a shaft.
When the shaft rotates, the vanes built into the
cylinder block assembly are opened by centrifugal
force.
This changes the volume of the space formed by the
rotor and cylinder, resulting in the intake and
compression of the refrigerant gas. The discharge
valve and the
valve stopper, which protects the
discharge valve, are
built into the cylinder block
assembly. There is no suction valve but a shaft seal
is
installed between the shaft and head; a trigger
valve, which applies back pressure to the vanes, is
installed in the cylinder block and a refrigerant gas
temperature sensor is installed in the front head.
The specified
quantity of compressor oil is contained
in
the compressor to lubricate the various parts
using
the refrigerant gas discharge pressure.
The thermo sensor is installed to the front head of
the compressor to protect it by stopping its
operation when the refrigerant gas is insufficient or
when the temperature get abnormally high.
•OFF ..... 160 ±soc (320.0 ± 9.0°F)
•ON ..... 135 ±soc (275.0 ± 9.0°F)
The oil used in the HFC-134a system compressor
differs from that used in R-12 systems.
Also, compressor
oil to be used varies according to
the compressor model. Be sure to avoid mixing two
or more different types of oil.
If the wrong oil is used, lubrication will be poor and
the compressor will seize or malfunction.
The specified
amount of the compressor oil is
150cc (5.0 fl.oz.).

POWER STEERING SYSTEM TEST
TEST PROCEDURE
Test of fluid pressure in the power steering system is
performed to determine whether
or not the oil pump
and
power steering unit are functioning normally.
The power steering system test is method used to
identify and
isolate hydraulic circuit difficulties. Prior
to performing this test, the following inspections and
corrections,
if necessary, must be made.
[!) INSPECT
• Pump reservoir for proper fluid level.
•
Pump belt for proper tension.
• Pump driver pulley condition.
1. Place a container under the pump to catch the
fluid when disconnecting or connecting the
hoses.
2. With the engine NOT running, disconnect the
pressure hose
at the power steering pump and
install Power Steering tester (Fig. 3B1-3).
The gage
must be between the shutoff valve and
pump.
Open the shutoff valve.
li5\l Tester: J-29877-A
~ Adapter: J-39213
3. Check the fluid level. Fill the reservoir with power
steering fluid, to the "Full" mark. Start the engine
and,
momentarily holding steering wheel against
stop, check the connections at tester
for leakage.
4. Bleed the system. Refer to "Bleeding the Power
Steering
System".
POWER STEERING GEAR AND PUMP 381-3
5. Start the engine and check the pump fluid level.
And power steering fluid if required. When the
engine is at
normal operating temperature,
increase engine speed to 1500 rpm.
U7 CAUTION:
VI Do not leave shutoff valve fully closed for more
than 5 seconds,
as the pump could become
damaged
internally.
6. Fully close the shutoff valve. Record the highest
pressures.
• If the pressure recorded is within 9300-9800
kPa (1350-1420 psi), the pump is functioning
within its specifications.
• If the pressure recorded is higher than 9800 kPa
(1420 psi), the valve in the pump is defective.
• If the pressure recorded is lower than 9300 kPa
(1350 psi), the valve or the rotating group in the
pump is defective.
7. If the pump checks within specifications, leave the
valve open and turn (or have someone else turn)
the steering
wheel fully in both directions. Record
the highest pressures and compare
with the
maximum pump pressure recorded in step
6. If
this pressure cannot be built in either (or one) side
ofthe gear, the gear is leaking internally and must
be disassembled and repaired.
8. Shut the engine off, remove the testing gage,
reconnect the pressure hose, check the
fluid level
and make the needed repairs.
9. If the problem still exists, the steering and front
suspension must be thoroughly examined.
Shut off Valve
J-29877-A
Oil Pressure Gauge
J-29877-A
Fig. 3B1-3

381 - 4 POWER STEERING GEAR AND PUMP
ON-VEHICLE SERVICE
MAINTENANCE
The hydraulic system should be kept clean and fluid
level in the reservoir should be checked at regular
intervals
and fluid added when required. Refer to
"MAINTENANCE AND LUBRICATION" in section OB
ofthe manual for type offluid to be used and intervals
for filling.
If the system contains some dirt, flush it as detailed
later
in this section. If it is exceptionally dirty, both the
pump and the gear must be completely disassembled
before further usage.
All tubes, hoses, and fittings should be inspected for
leakage at regular intervals. Fittings must be tight.
Make sure the clips, clamps and supporting tubes and
hoses are in
place and properly secured.
Power steering hoses and lines must not be twisted,
kinked or tightly bent. Air in the system will cause
spongy action and noisy operation. When a hose is
disconnected
or when fluid is lost, for any reason, the
system must be bled after refilling. Refer to "Bleeding
the Power Steering System" in this section.
FLUID LEVEL
1. Run the engine until the power steering fluid
reaches normal operating temperature, about
55°C (130°F), then shut the engine off.
2. Check the level of fluid in the reservoir.
3. If the fluid level is low, add power steering fluid
as specified in "MAINTENANCE AND LUBRI­
CATION" in Section OB to the proper level and
install the receiver cap.
4. When checking the fluid level after the steering
system has been serviced,
air must be bled from
the system. Refer to "Bleeding the Power
Steering
System" in this section.
BLEEDING THE POWER STEERING
SYSTEM
When a power steering pump or gear has been
installed, or an oil line has been disconnected, the air
that has entered the system must be bled out before
the vehicle is operated. If air is allowed to remain in
the power steering fluid system, noisy and
unsatisfactory operation of the system may result.
BLEEDING PROCEDURE
When bleeding the system, and any time fluid is
added
to the power steering system, be sure to use
only power steering fluid as specified in
"MAINTENANCE AND LUBRICATION" in section OB.
1. Fill the pump fluid reservoir to the proper level
and let the fluid settle for at least two minutes.
2. Start the engine and let it run for a few seconds.
Do
not turn the steering wheel. Then turn the
engine off.
3. Add fluid if necessary.
4. Repeat the above procedure until the fluid level
remains constant after running the engine.
5. Raise the front end of the vehicle so that the
wheels are off the ground.
6. Start the engine. Slowly turn the steering wheel
right and left, lightly contacting the wheel stops.
7. Add power steering fluid if necessary.
8. Lower the vehicle and turn the steering wheel
slowly from lock to lock.
9. Stop the engine. Check the fluid level and refill
as required.
10.
If the fluid is extremely foamy, allow the vehicle
to stand a few minutes and repeat the above
procedure.
~ INSPECT
• Belt for tightness.
• Pulley for looseness or damage. The pulley
should not wobble with the engine running.
• Hoses so they are not touching any other parts
of the vehicle.
• Fluid level
and fill to the proper level.
FLUSHING THE POWER STEERING
SYSTEM
1. Raise the front end of the vehicle off the ground
until the wheels are free to turn.
2. Remove the fluid return line at the pump inlet
connector and plug the connector port on the
pump.
Position the line toward a large container to
catch the draining fluid.
3. While running the engine at idle, fill the reservoir
with new power steering fluid. Turn the steering
wheel in both directions. DO NOT contact wheel
stops or hold the wheel in a corner, or fluid will
stop and the pump will be in pressure relief mode.
A sudden
overflow from the reservoir may
develop if the wheel is held at a stop.
4. Install all the lines and hoses. Fill the system with
new power steering fluid and bleed the system
as described in "Bleeding The Power Steering
System". Operate the engine for about 15
minutes.
Remove the
pump return line at the pump inlet
and plug the connection on the pump. While
refilling the reservoir, check the draining fluid for
contamination. If foreign material is still evident,
replace all lines, disassemble and clean or replace
the power steering system components. Do not
re-use any drained power steering fluid.
~
~

6-4 ENGINE DIAGNOSIS
HARD STARTING (Cont'd)
4. Engine lacks compression
Condition Possible cause
Spark plug loosely fitted or spark plug
gasket defective
Valve timing incorrect
Cylinder head gasket defective
Valve incorrectly seated
Valve stem seized
Valve spring weakened
Cylinder or piston rings worn
Piston ring seized
ENGINE COMPRESSION TEST
PROCEDURE
1. Start and run the engine until the engine reaches
normal operating temperature.
2. Turn the engine off.
3. Remove all the spark plugs.
4. Remove ignition coil fuse (15A) and disable the
ignition system.
5. Remove the fuel pump relay from the relay and
fuse box.
6. Engage the starter and check that the cranking
speed is approximately
300 rpm.
7. Install cylinder compression gauge into spark plug
hole.
8. With the throttle valve opened fully, keep the
starter engaged
until the compression gage
needle reaches the
maximum level. Note the
reading.
9. Repeat the test with each cylinder.
If
the compression pressure obtained falls below the
limit, engine overhaul is necessary.
Limit; 883
kPa (128 psi) Correction
Tighten
to specified torque or
replace gasket
Adjust
Replace gasket
Lap
valve
Replace valve
and valve guide
Replace
Overhaul engine
Overhaul engine.

6-6 ENGINE DIAGNOSIS
ROUGH ENGINE RUNNING
Complaint
Faulty parts Possible cause Correction
Engine misfires Ignition coil
Coil layer shorted Replace
regularly
high-tension Primary lead wire broken leakage due
Correct cables to defective insulator
Spark plugs
Fouling Clean
or install hotter type
plug
Insulator
nose leaking Replace
Fuel
injectors Fuel injector(s) defective Replace
Dropping register defective Replace
Engine Control
Faulty Replace
Module
Engine knocks Spark plugs
Spark plugs running too hot Install colder type spark
regularly
plugs
Engine Control Faulty
Replace
Module
Engine lacks Spark plugs
Fouled Clean
power Multipart Fuel
Fuel injectors defective Replace
Injection Manifold Absolute Pressure (MAP)
Correct or replace system Sensor or Manifold Absolute Pressure
Sensor
circuit defective
Engine
Coolant Temperature Sensor or Correct or replace
Engine Coolant Temperature Sensor
circuit dcefective
Engine
Control Module faulty Replace
Intake
Air Temperature Sensor or Intake
Air Temperature Sensor circuit Correct or replace
defective
Throttle Position Sensor or Throttle Correct or replace
Position Sensor
circuit defective
Knock
Sensor or Knock Sensor circuits Correct or replace
defective (DOHC only)
Knock Sensor Module or Knock Sensor Correct or replace .
Module
circuits defective (DOHC only)
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