2002 ISUZU AXIOM compression pressure

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±19
Evaporation
The refrigerant is changed from a liquid to a gas inside the
evaporator. The refrigerant mist that enters the
evaporator vaporizes readily. The liquid refrigerant
removes the required quantity of heat (latent heat of
vaporization) from the air around the evaporator 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 as 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 temperatures close to 0
C
(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.
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
The 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.
It pumps refrigerant and refrigerant oil through the air
conditioning system.
This vehicle is equipped with a five-vane rotary
compressor.
The specified amount of the compressor oil is 150cc
(5.0 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 activated 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 compressor 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. Refer to
Compressor in this section for magnetic
clutch repair procedure.
871RX026
Legend
(1) Magnetic Clutch
(2) Magnetic Clutch Connector
(3) Compressor
Condenser
The condenser assembly is located in front of the radiator.
It provides rapid heat transfer from the refrigerant to the
cooling fins.
Also, it functions to cool and liquefy the high-pressure and
high-temperature vapor sent from the compressor by the
radiator fan or outside air.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±27
ConditionPossible causeCorrection
Discharge (High Gauge) Pressure
Abnormally High
Condenser clogged or dirty.Clean the condenser fins
Abnormally HighCooling fan does not operate
properly.Check the cooling fan operation.
Discharge (High Gauge) Pressure
Abnormally High.
Insufficient cooling.Excessive refrigerant in system.Discharge and recover refrigerant.
Recharge to specified amount.
Discharge (High Gauge) Pressure
Abnormally High.
High pressure gauge drop. (After
stopping A/C, the pressure drops
approx. 196 kPa (28 psi) quickly)Air in system.Evacuate and charge refrigerant
system.
Discharge (High Gauge) Pressure
Abnormally Low.
Insufficient coolingInsufficient refrigerant in system.Check for leaks. Discharge and
recover the refrigerant. Recharge to
the specified amount.
Discharge (High Gauge) Pressure
Abnormally Low.
Low pressure gauge indicates
vacuum.Clogged or defective expansion
valve.Replace the expansion valve.
Discharge (High Gauge) Pressure
Abnormally Low.
Frost or dew on refrigerant line
before and after the receiver/drier or
expansion valve, and low pressure
gauge indicates vacuum.Restriction caused by debris or
moisture in the receiver/drier.Check system for restriction and
replace the receiver/drier.
Discharge (High Gauge) Pressure
Abnormally Low.Compressor seal defectiveRepair or replace the compressor.
High and low pressure gauge
balanced quickly. (After turned off
A/C)Poor compression due to a defective
compressor gasket.Repair or replace the compressor.
Suction (Low Gauge) Pressure
Abnormally High.
Low pressure gauge (Low pressure
gauge is lowered after condenser is
cooled by water.)Excessive refrigerant in system.Discharge and recover refrigerant
Recharge to specified amount.
Suction (Low Gauge) Pressure
Abnormally High.
Low pressure hose temperature.
(Low pressure hose temperature
around the compressor refrigerant
Unsatisfactory valve operation due
to defective temperature sensor of
expansion valve.Replace the expansion valve.
around the com ressor refrigerant
line connector is lower than around
evaporator.)Expansion valve opens too long.Replace the expansion valve.
Suction (Low Gauge) Pressure
Abnormally High.
High and low pressure gauge
balanced quickly. (After turned off
A/C)Compressor gasket is defective.Repair or replace the compressor.
Suction (Low Gauge) Pressure
Abnormally Low.
Insufficient cooling.Insufficient refrigerant in system.Check for leaks. Discharge and
recover the refrigerant. Recharge to
specified amount.
Suction (Low Gauge) Pressure
Abnormally Low.
Frost on the expansion valve inlet
lineExpansion valve clogged.Replace the expansion valve.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±53
Compressor
Service Precaution
WARNING: THIS VEHICLE HAS A SUPPLEMENTAL
RESTRAINT SYSTEM (SRS). REFER TO THE SRS
COMPONENT LOCATION VIEW IN ORDER TO
DETERMINE WHETHER YOU ARE PERFORMING
SERVICE ON OR NEAR THE SRS COMPONENTS OR
THE SRS WIRING. WHEN YOU ARE PERFORMING
SERVICE ON OR NEAR THE SRS COMPONENTS OR
THE SRS WIRING, REFER TO THE SRS ON-VEHICLE
SERVICE INFORMATION. FAILURE TO FOLLOW
CAUTIONS COULD RESULT IN POSSIBLE AIR BAG
DEPLOYMENT, PERSONAL INJURY, OR
OTHERWISE UNNEEDED SRS SYSTEM REPAIRS.
CAUTION: Always use the correct fastener in the
proper location. When you replace a fastener, use
ONLY the exact part number for that application.
ISUZU will call out those fasteners that require a
replacement after removal. ISUZU will also call out
the fasteners that require thread lockers or thread
sealant. UNLESS OTHERWISE SPECIFIED, do not
use supplemental coatings (paints, greases, or other
corrosion inhibitors) on threaded fasteners or
fastener joint interfaces. Generally, such coatings
adversely affect the fastener torque and the joint
clamping force, and may damage the fastener. When
you install fasteners, use the correct tightening
sequence and specifications. Following these
instructions can help you avoid damage to parts and
systems.
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
ºOn±Vehicleº 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
Trichloroethane, 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.
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 tosee if the drive plate can be rotated. If rotation is
impossible, the compressor is seized. Low discharge
pressure may be due to a faulty internal seal of the
compressor, or a restriction in the compressor. Low
discharge pressure 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.
The compressor 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.
DKV-14G Type Compressor
DKV±14G is equipped with five±vane rotary compressor.
These vanes are built into a rotor which is mounted on a
shaft.
When the shaft rotates, the vanes built into the cylinder
block assembly are operated by centrifugal force.
This changes the volume of the spare 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.
871RX002

6A±3
ENGINE MECHANICAL (6VE1 3.5L)
General Description
Engine Cleanliness And Care
An automobile engine is a combination of many
machined, honed, polished and lapped surfaces with
tolerances that are measured in the thousandths of a
millimeter (ten thousandths of an inch). Accordingly,
when any internal engine parts are serviced, care and
cleanliness are important. Throughout this section, it
should be understood that proper cleaning and protection
of machined surfaces and friction areas is part of the
repair procedure. This is considered standard shop
practice even if not specifically stated.

A liberal coating of engine oil should be applied to all
friction areas during assembly to protect and lubricate
the surfaces on initial operation.

Whenever valve train components, pistons, piston
rings, connecting rods, rod bearings, and crankshaft
journal bearings are removed for service, they should
be retained in order.

At the time of installation, they should be installed in
the same locations and with the same mating
surfaces as when removed.

Battery cables should be disconnected before any
major work is performed on the engine. Failure to
disconnect cables may result in damage to wire
harness or other electrical parts.

The six cylinders of this engine are identified by
numbers; Right side cylinders 1, 3 and 5, Left side
cylinders 2, 4 and 6, as counted from crankshaft
pulley side to flywheel side.
General Information on Engine Service
The following information on engine service should be
noted carefully, as it is important in preventing damage
and contributing to reliable engine performance.

When raising or supporting the engine for any reason,
do not use a jack under the oil pan. Due to the small
clearance between the oil pan and the oil pump
strainer, jacking against the oil pan may cause
damage to the oil pick±up unit.

The 12±volt electrical system is capable of damaging
circuits. When performing any work where electrical
terminals could possibly be grounded, the ground
cable of the battery should be disconnected at the
battery.

Any time the intake air duct or air cleaner is removed,
the intake opening should be covered. This will
protect against accidental entrance of foreign
material into the cylinder which could cause extensive
damage when the engine is started.
Cylinder Block
The cylinder block is made of aluminum die±cast casting
for 75
V±type six cylinders. It has a rear plate integrated
structure and employs a deep skirt. The cylinder liner is
cast and the liner inner diameter and crankshaft journal
diameter are classified into grades. The crankshaft is
supported by four bearings of which width is different
between No.2, No.3 and No.1, No.4; the width of No.3
bearing on the body side is different in order to support the
thrust bearing. The bearing cap is made of nodular cast
iron and each bearing cap uses four bolts and two side
bolts.
Cylinder Head
The cylinder head, made of aluminum alloy casting
employs a pent±roof type combustion chamber with a
spark plug in the center. The intake and exhaust valves
are placed in V±type design. The ports are cross±flow
type.
Valve Train
Intake and exhaust camshaft on both banks are driven
with a camshaft drive gear by the timing belt. The valves
are operated by the camshaft and the valve clearance is
adjusted to select suitable thickness shim.
Intake Manifold
The intake manifold system is composed of the aluminum
cast common chamber and intake manifold attached with
six fuel injectors.
Exhaust Manifold
The exhaust manifold is made of nodular cast iron.
Pistons and Connecting Rods
Aluminum pistons are used after selecting the grade that
meets the cylinder bore diameter. Each piston has two
compression rings and one oil ring. The piston pin made
of chromium steel is offset 1mm toward the thrust side,
and the thrust pressure of piston to the cylinder wall varies
gradually as the piston travels. The connecting rods are
made of forged steel. The connecting rod bearings are
graded for correct size selection.
Crankshaft and Bearings
The crankshaft is made of Ductile cast±iron. Pins and
journals are graded for correct size selection for their
bearing.

6A±5
ENGINE MECHANICAL (6VE1 3.5L)
4. Engine Lacks Compression
Condition
Possible causeCorrection
Engine lacks compressionSpark plug loosely fitted or spark
plug gasket defectiveTighten to specified torque or replace
gasket
Valve timing incorrectAdjust
Cylinder head gasket defectiveReplace gasket
Valve incorrectly seatedLap valve
Valve stem seizedReplace valve and valve guide
Valve spring weakened or brokenReplace
Cylinder or piston rings wornOverhaul engine
Piston ring seizedOverhaul engine.
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; 1000 kPa (145 psi)

6A±6
ENGINE MECHANICAL (6VE1 3.5L)
Rough Engine Idling or Engine Stalling
ConditionPossible causeCorrection
Trouble in fuel injection systemThrottle shutting off incompleteCorrect or replace
Throttle position sensor circuit open
or shortedCorrect or replace
Fuel injector circuits open or shortedCorrect or replace
Fuel injectors damagedReplace
Fuel pump relay defectiveReplace
Mass Airflow Sensor circuit open or
poor connectionsCorrect or replace
Mass Airflow Sensor defectiveReplace
Manifold Absolute Pressure Sensor
circuit open or poor connectionsCorrect or replace
Manifold Absolute Pressure Sensor
defectiveReplace
Engine Coolant Temperature Sensor
circuit open or poor connectionsCorrect or replace
Engine Coolant Temperature Sensor
defectiveReplace
Intake Air Temperature sensor circuit
open or poor connectionsCorrect or replace
Intake Air Temperature sensor
defectiveReplace
Ion Sensing Module cable broken or
poor connectionsCorrect or replace
Ion Sensing Module defectiveReplace
Vehicle Speed Sensor circuit open or
shortedCorrect or replace
Vehicle Speed Sensor defectiveReplace
Trouble in emission control systemPowertrain Control Module defectiveReplace
Exhaust Gas Recirculation Valve
circuit open or poor connectionsCorrect or replace
Exhaust Gas Recirculation Valve
faultyReplace
Canister purge valve circuit open or
poor connectionsCorrect or replace
Canister purge valve defectiveReplace
Evaporative Emission Canister
Purge control valve defectiveReplace
Trouble in ignition systemRefer to ªHard Startº
OthersEngine lacks compressionRefer to ªHard Startº
Valve incorrectly seatedLap valve
Air Cleaner Filter cloggedReplace filter element
Valve timing incorrectReadjust
Idle air control valve brokenReplace
Fast idle solenoid defectiveReplace
Positive Crankcase Ventilation valve
defective or cloggedReplace

6A±11
ENGINE MECHANICAL (6VE1 3.5L)
Condition CorrectionPossible cause
Engine overheatingLevel of Engine Coolant too lowReplenish
Fan clutch defectiveReplace
Incorrect fan installedReplace
Thermostat defectiveReplace
Engine Coolant pump defectiveCorrect or replace
Radiator cloggedClean or replace
Radiator filler cap defectiveReplace
Level of oil in engine crankcase too
low or wrong engine oilChange or replenish
Resistance in exhaust system
increasedClean exhaust system or replace
defective parts
Throttle Position Sensor adjustment
incorrectReplace with Throttle Valve ASM
Throttle Position Sensor circuit open
or shortedCorrect or replace
Cylinder head gasket damagedReplace
Engine overcoolingThermostat defectiveReplace (Use a thermostat set to
open at 82
C (180
F))
Engine lacks compressionÐÐÐÐRefer to Hard Start
OthersTire inflation pressure abnormalAdjust to recommended pressures
Brake dragAdjust
Clutch slippingAdjust or replace
Level of oil in engine crankcase too
highCorrect level of engine oil
Exhaust Gas Recirculation Valve
defectiveReplace

6A±87
ENGINE MECHANICAL (6VE1 3.5L)
Main Data and Specification
General Specification
ItemSpecificationsItem6VE1
Engine type, number of cylinders and arrangementWater cooled, four cycle V6
Form of combustion chamberPent-roof type
Valve mechanism4-Cams, 4-Valves, DOHC Gear & Belt Drive
Cylinder liner typeCasted in cylinder drive
Total piston displacement3494 cc
Cylinder bore x stroke93.4mm x 85mm
(3.677 in x 3.346 in)
Compression ratio9.1
Compression pressure at 300rpm1.37 MPa (14.0 Kg/cm2)
Engine idling speed rpmNon adjustable (750)
Valve clearanceIntake: 0.28 mm (0.11 in)
Exhaust: 0.30mm (0.12in)
Oil capacity5.3 liters
Ignition timingNon adjustable (20
BTDC at idle rpm)
Spark plugPK16PR11, RC10PYP4, K16PR-P11
Plug gap1.0 mm±1.1 mm(0.0394 in ± 0.0433 in)