ISUZU TROOPER 1998 Service Repair Manual

SERVICE INFORMATION 00 Ð 11
8. DARK EXHAUST SMOKE
Checkpoint Possible cause Correction
Air cleaner Clogged air cleaner element Clean or replace the air cleaner
element
Injection nozzle Injection nozzle injection starting pressure
too low
Improper spray conditionAdjust or replace the injection
nozzle
Fuel injection timing Fuel injection timing improperly adjusted Adjust the fuel injection timing
Injection pump Defective Delivery valve resulting is fuel
drippage after fuel injectionReplace the delivery valve
Excessive injection volume Adjust the injection volume
9. OIL PRESSURE DOES NOT RISE
Checkpoint Possible cause Correction
Engine oil Improper viscosity engine oil. Insufficient
engine oilReplace the engine oil
Correct the engine oil volume
Oil pressure gauge
or unit
Oil pressure indicator
lightDefective oil pressure gauge or unit
Defective indicator lightRepair or replace the oil pressure
gauge or unit
Replace the indicator light
Oil filter Clogged oil filter element Replace the oil filter element or the
oil filter cartridge
Relief valve and by-
pass valveRelief valve sticking and/or weak by-pass
valve springReplace the relief valve and/or the
by-pass valve spring
Oil pump Clogged oil pump strainer Clean the oil pump strainer
Worn oil pump related parts Replace the oil pump related parts
Rocker arm shaft Worn rocker arm bushing Replace the rocker arm bushing
Camshaft Worn camshaft and camshaft bearing Replace the camshaft and the
camshaft bearing
Crankshaft and
bearingsWorn crankshaft and bearings Replace the crankshaft and/or the
bearings

00 Ð 12 SERVICE INFORMATION
10. ABNORMAL ENGINE NOISE
Checkpoint Possible cause Correction
Fuel Fuel unsuitable Replace the fuel
1. ENGINE KNOCKING
2. GAS LEAKAGE NOISE
Exhaust pipes Loosely connected exhaust pipes. Broken
exhaust pipesTighten the exhaust pipe
connections
Replace the exhaust pipes Check to see that the engine has been thoroughly warmed up before begining the troubleshooting
procedure.
Fuel injection timing Fuel injection timing improperly adjusted Adjust the fuel injection timing
Injection nozzle Improper injection nozzle starting pressure
and spray conditionAdjust or replace the injection
nozzle
Compression
pressureBlown out head gasket
Broken piston ringReplace the head gasket or the
piston ring
Injection nozzles
and/or glow plugsLoose injection nozzles and/or glow plugs Replace the washers
Tighten the injection nozzles and/or
the glow plugs
Exhaust manifold Loosely connected exhaust manifold and/or
glow plugsTighten the exhaust manifold
connections
Cylinder head gasket Damaged cylinder head gasket Replace the cylinder head gasket
3. CONTINUOUS NOISE
Fan belt Loose fan belt Readjust the fan belt tension
Cooling fan Loose coling fan Retighten the cooling fan
Water pump bearing Worn or damaged water pump bearing Replace the water pump bearing
Alternator or vacuum
pumpDefective alternator or vacuum pump Repair or replace the alternator or
the vacuum pump
Valve clearance Clearance improperly adjust Adjust the valve clearance

SERVICE INFORMATION 00 Ð 13
Checkpoint Possible cause Correction 4. SLAPPING NOISE
Valve clearance Valve clearance improperly adjusted Adjust the valve clearance
Rocker arm Damaged rocker arm Replace the rocker arm
Flywheel Loose flywheel bolts Retighten the flywheel bolts
Crankshaft and
thrust bearingsWorn or damaged crankshaft and/or
thrust bearingsReplace the crankshaft and/or the
thrust bearings
Crankshaft and
connecting rod
bearingsWorn or damaged crankshaft and/or
connecting rod bearingsReplace the crankshaft and/or the
connecting rod bearings
Connecting rod
bushing and piston
pinWorn or damaged connecting rod bushing
and piston pinReplace the connecting rod bushing
and/or the piston pin
Piston and cylinder
linerWorn or damaged piston and cylinder liner.
Foreign material in the cylinder.Replace the piston and the cylinder
liner.

00 Ð 14 SERVICE INFORMATION
Condition Possible cause Correction
Engine overheating Low coolant level Replenish
Thermo unit faulty
Faulty thermostat
Faulty coolant unit
Clogged radiator
Faulty radiator cap
Low engine oil level or use of improper
engine oil
Damaged cylinder head gasket
Clogged exhaust system
Loose fan belt
Excessive fuel injected
Improper injection timing
Injection timing improper
Faulty thermostat
Faulty thermostatReplace
Replace
Repair or replace
Clean or replace
Replace
Replenish or change oil
Replenish
Replace
Clean exhaust system or replace
faulty parts
Adjust
Adjust
Adjust
Replace
Replace
Thermo unit faultyReplace Engine overcooling
Too long engine
warm-up time
Adjust
ENGINE COOLING TROUBLE

SERVICE INFORMATION 00 Ð 15
ENGINE ELECTRICAL
Check if the battery is normal, then perform the following diagnosis.
STARTER DOES NOT RUN
CHECK BATTERY
CHARGING FAILURE OR LIFE
CHECK BATTERY
BATTERY IS NORMAL
CHECK TERMINAL CONNECTION
CONNECTION FAILURE
CLEAN BATTERY TERMINALS, AND RECONNECT
TERMINAL CONNECTION IS NORMAL
CHECK STARTER OR STARTER SWITCH
FAILURE
REPAIR OR REPLACE
TURN ON HEAD LAMP AND STARTER SWITCH
HEAD LAMP DOES NOT COME ON
OR IT IS EXTREMELY DARK
a) LACK OF BATTERY CHARGING
b) SHORT-CIRCUIT IN STARTER COIL
c) FAULTY STARTER PARTS
HEAD LAMP ILLUMINATES
a) DISCONNECTED STARTER CIRCUIT
b) DISCONNECTED STARTER COIL
c) FAULTY STARTER SWITCH

00 Ð 16 SERVICE INFORMATION
FAULTY MESHING OR PINION AND RING GEAR
CHECK IF BATTERY VOLTAGE IS PRESENT AT
MAGNETIC SWITCH TERMINAL “S” WHEN
STARTER SWITCH IS TURNED TO “START (ST)”
YESNO
EXTREME WEAR OF
PINION AND RING
GEARSTARTER SLIDING
RESISTANCE IS
LARGE
REPAIR OR REPLACE
STARTER. REPLACE
RING GEARREPAIR OR REPLACE
STARTER
UNDER THIS CONDITION, CHECK IF VOLTAGE
OF CONNECTOR 3BW ON MAGNETIC SWITCH
OF RESTART RELAY IS NORMAL
DISCONNECTION OR
FAULTY CONNECTION
BETWEEN STARTER
SWITCH AND MAGNETIC
SWITCHCHECK IF VOLTAGE IS
PRESENT AT WIRING
CONNECTOR 3BW ON
STARTER SWITCH OF
RESTART RELAY
YESNO
REPAIR
YESNO
FAULTY CONNECTION
OF STARTER SWITCH DISCONNECTION OR
FAULTY CONNECTION
BETWEEN STARTER
SWITCH AND BATTERY
REPLACE STARTER
SWITCH
REPAIR
OR

SERVICE INFORMATION 00 Ð 17
MAGNETIC SWITCH DOES NOT OPERATE THOUGH
STARTER SWITCH IS TURNED TO “START (ST)”
CHECK IF VOLTAGE IS PRESENT AT MAGNETIC
SWITCH TERMINAL “S” WHEN STARTER SWITCH
IS TURNED TO “START (ST)”
YESNO
CHECK IF INDICATOR LAMP ON
METER COMES ON NORMALLY
CHECK CONTINUITY
STARTER SWITCH AND
MAGNETIC SWITCH
TERMINAL “S”DISCONNECTION OR
FAULTY CONNECTION
BETWEEN BATTERY
AND STARTER SWITCH
YESNO
CHECK GROUND CABLE
YESNO
PINION
SLIDING
PART DOES
NOT MOVEMAGNETIC SWITCH
OR COIL IS
DISCONNECTED
OR BURNED OUT
REPAIR
REPAIR OR REPLACE STARTER
REPAIR
CHECK STARTER
RELAYFAULTY CONNECTION
OR STARTER SWITCH
CHECK CLUTCH
START SWITCHREPLACE STARTER
SWITCH
OR

00 Ð 18 SERVICE INFORMATION
PINION MESHES WITH RING GEAR BUT
ENGINE DOES NOT RUN
CHECK GROUND CABLE
YESNO
REPAIR OR REPLACE
GROUND CABLE
FAULTY CONNECTION
OF BRUSH AND
COMMUTATORBURNED-OUT
MAGNETIC
STARTER SWITCHDISCONNECTION
OR DAMAGE OF
FIELD COILDISCONNECTION
OR DAMAGE OF
ARMATURE COILSLIP OF
PINION
CLUTCH
REPAIR OR REPLACE STARTER

SERVICE INFORMATION 00 Ð 19
STARTER DOES NOT STOP THOUGH STARTER
SWITCH IS RETURNED TO “ON”
YESNO
REPLACE STARTER SWITCHMAGNETIC SWITCH CONTACTS
ARE FUSED AND NOT MOVED, OR
A RETURN SPRING IS BROKEN OR
DETERIORATED
DISCONNECTED STARTER SWITCH WIRING CONNECTOR, AND CHECK STARTER SWITCH OPERATION.
THERE MUST BE NO CONTINUITY EXCEPT ABOVE LINES
KEY
POSITIONBATTERY
B1
LOCK
OFF
ACC
ON
START
IGNITION
IG1BATTERY
B2ACCESSORIES
ACCIGNITION
IG2STARTER
ST
REPLACE MAGNETIC SWITCH

00 Ð 20 SERVICE INFORMATION
MAIN DATA AND SPECIFICATIONS
GENERAL SPECIFICATIONS
Engine type
Camshaft type
Cylinder line-type
Number of cylinders
Bore x stroke
Total piston displacement
Compression ratio
Engine weight (dry)
Engine idling speed (Reference)
Compression pressure
Firing order
Injection timing
VALVE SYSTEM
Intake valves
Exhaust valve
Valve clearance at
Oil filter
Oil capacity (Original factory fill or rebuilt engine)
Oil capacity (Service change)
with filter change
without filter change
Oil cooler
Inter cooler
Turbocharger
Control method
Lubrication method
Cooling method
(mm)
(cc)
(to 1)
N (kg/lb)
RPM
open at:
close at:
open at:
close at:
cold
intake:
exhaust:mm (in)Diesel, four cycle water cooled inline
Overhead valve
Dry type
4
95.4 x 107
3,059
20.0
2353 (240/529)(4JG2-NA)
2597 (265/584)(4JG2-T)
750 (4JG2-NA)
720 (4JG2-T)
2940 (30/426)-200
1–3–4–2
1¡A.T.D.C (4JG2-NA)
T.D.C. (4JG2-T)
B.T.D.C. 24¡
A.B.D.C. 55¡
B.B.D.C. 54¡
A.T.D.C. 26¡
0.40 (0.016)
0.40 (0.016)
Full flow and bypass combined type
7.1 liters (6.3 US quarts)
6.0 liters (6.3 US quarts)
5.0 liters (5.3 US quarts)
Water cooled type
Air cooled type
Wastegate control
Pressurized control
Coolant cooled kpa (kg/cm /psi)-rpm
2