width ISUZU TROOPER 1998 Service Owner's Manual

6E±151 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0152 HO2S Circuit HIGH Voltage Bank 2
Sensor 1
060RW190
Circuit Description
The powertrain control module (PCM) supplies a bias
voltage of about 450 mV between the heated oxygen
sensor (HO2S) signal high and signal low circuits. When
measured with a 10 megaohm digital voltmeter, this may
display as low as 320 mV. The oxygen sensor varies the
voltage within a range of about 1000 mV when the
exhaust is rich, down through about 10 mV when exhaust
is lean. The PCM constantly monitors the HO2S signal
during ªclosed loopº operation and compensates for a rich
or lean condition by decreasing or increasing the injector
pulse width as necessary. If the Bank 2 HO2S 1 voltage
remains excessively high for an extended period of time,
DTC P0152 will be set.
Conditions for Setting the DTC

No related DTCs.

The engine is operating in ªclosed loop.º

The engine coolant temperature is above 60
C
(140
F).

ªClosed loopº commanded air/fuel ratio between 14.5
and 14.8.

Throttle angle between 3% and 19%.

Bank 2 HO2S 1 signal voltage remains above 952 mV
during normal ªclosed loopº operation for a total of 77
seconds over a 90-second period.
OR
Bank 2 HO2S 1 signal voltage remains above 500 mV
during deceleration fuel cutoff mode operation for up to
3 seconds.
Action Taken When the DTC Sets

The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.

The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.

ªOpen loopº fuel control will be in effect.
Conditions for Clearing the MIL/DTC

DTC P0152 can be cleared by using Tech 2 ªClear Infoº
function or by disconnecting the PCM battery feed.
Diagnostic Aids
Check for the following conditions:

Fuel pressure ± The system will go rich if pressure is
too high. The PCM can compensate for some
increase. However, if fuel pressure is too high, a DTC
P0152 may be set. Refer to
Fuel System Diagnosis.

Rich injector(s) ± Perform ªInjector Balance Test.º

Leaking injector ± Refer to
Fuel System Diagnosis.

Evaporative emissions (EVAP) system ± Check the
canister for fuel saturation. If the canister is full of fuel,
check EVAP control system components and hoses.
Refer to
Evaporative Emission (EVAP) Control
System.

6E±336
ENGINE DRIVEABILITY AND EMISSIONS
0016
Electrically Erasable Programmable Read
Only Memory (EEPROM)
The electrically erasable programmable read only
memory (EEPROM) is a permanent memory chip that is
physically soldered within the PCM. The EEPROM
contains the program and the calibration information that
the PCM needs to control powertrain operation.
Unlike the PROM used in past applications, the EEPROM
is not replaceable. If the PCM is replaced, the new PCM
will need to be programmed. Equipment containing the
correct program and calibration for the vehicle is required
to program the PCM.
Fuel Control Heated Oxygen Sensors
The fuel control heated oxygen sensors (Bank 1 HO2S 1
and Bank 2 HO2S 1) are mounted in the exhaust stream
where they can monitor the oxygen content of the exhaust
gas. The oxygen present in the exhaust gas reacts with
the sensor to produce a voltage output. This voltage
should constantly fluctuate from approximately 100 mV to
900 mV. The heated oxygen sensor voltage can be
monitored with Tech 2. By monitoring the voltage output
of the oxygen sensor, the PCM calculates the pulse width
command for the injectors to produce the proper
combustion chamber mixture.

Low HO2S voltage is a lean mixture which will result in
a rich command to compensate.

High HO2S voltage is a rich mixture which will result in
a lean command to compensate.
An open Bank 1 HO2S 1 signal circuit will set a DTC
P0134 and Tech 2 will display a constant voltage between
400-500 mV. A constant voltage below 300 mV in the
sensor circuit (circuit grounded) will set DTC P0131. A
constant voltage above 800 mV in the circuit will set DTC
P0132. Faults in the Bank 2 HO2S 1 signal circuit will
cause DTC 0154 (open circuit), DTC P0151 (grounded
circuit), or DTC P0152 (signal voltage high) to set.
0012
Intake Air Temperature (IAT) Sensor
The intake air temperature (IAT) sensor is a thermistor
which changes its resistance based on the temperature of
air entering the engine. Low temperature produces a high
resistance of 100,000 ohms at ±40
C (±40
F). High
temperature causes low resistance of 70 ohms at 130
C
(266
F) . The PCM supplies a 5-volt signal to the sensor
through a resistor in the PCM and monitors the signal
voltage. The voltage will be high when the incoming air is
cold. The voltage will be low when the incoming air is hot.
By measuring the voltage, the PCM calculates the
incoming air temperature. The IAT sensor signal is used
to adjust spark timing according to the incoming air
density.
Tech 2 displays the temperature of the air entering the
engine. The temperature should read close to the
ambient air temperature when the engine is cold and rise
as underhood temperature increases. If the engine has
not been run for several hours (overnight), the IAT sensor
temperature and engine coolant temperature should read
close to each other. A fault in the IAT sensor circuit will set
DTC P0112 or DTC P0113.

SERVICE INFORMATION 00 Ð 23
SERVICE STANDARD
Engine Mechanicalmm (in)
Parts Items Service standard
Cylinder
HeadCylinder head deck, and
exhaust manifold mating
surface for flatness
Cylinder head height
Hot plug depression
Hot plug installation
pressure0.05 (0.0020) or less
92.0 (3.6220)
—
44000-54000N (4500–5500
kg/9923–12128 lbs)
0.2 (0.0079)
—
0.02 (0.0008)
—Service limit Remarks
Cannot be
reground
Free height
Squareness
Spring tension 48.0 (1.8898)
—
294 (30/66.1) Valve
Spring47.10 (1.8543)
1.7 (0.0669)
257.9 (26.3/57.9) At installed
height
38.9 (1.5) N (lb)
Diameter of Valve stem
Valve and valve guide
clearance
Valve guide upper end
height (Measured from the
Cylinder head upper face)
Valve guide margin
Valve thickness
Valve seat contact
surface angle
Valve seat contact width7.946–7.961
(0.3128–0.3134)
7.921–7.936
(0.3118–0.3124)
0.039–0.071
(0.0015–0.0028)
0.064–0.096
(0.0025–0.0038)
13.0 (0.5118)
1.1 (0.0433)
1.34 (0.0528)
1.38 (0.0543)
45¡
1.7 (0.0669)
2.0 (0.0787) Valve
and
Valve
Guide7.880 (0.3102)
7.850 (0.3091)
0.200 (0.0079)
0.250 (0.0098)
—
1.6 (0.0630)
1.1 (0.0433)
1.1 (0.0433)
—
2.2 (0.0866)
2.5 (0.0984) IN
EX
IN
EX
IN
EX
IN
EX
Curvature — Push rod
0.3 (0.0118)

ENGINE MECHANICAL 6A Ð 11
Valve Contact Width
1. Check the valve contact faces for roughness and
unevenness. Make smooth the valve contact sur-
faces.
2. Measure the valve contact width.
If the measured value exceeds the specified limit, the
valve seat insert must be replaced.
Valve Seat Insert Replacement
Valve Seat Insert Removal
1. Arc weld the entire inside circumference À of the
valve seat insert Á.
2. Allow the valve seat insert to cool for a few minutes.
This will invite contraction and make removal of the
valve seat insert easier.
3. Use a screwdriver  to pry the valve seat insert free.
Take care not to damage the cylinder head Ö .
4. Carefully remove carbon and other foreign material
from the cylinder head insert bore.
Valve Seat Insert Installation
1. Carefully place the attachment À (having a smaller
outside diameter than the valve seat insert) on the
valve seat insert Á .
Note:
The smooth side of the attachment must contact
the valve seat insert.
2. Use a bench press  to gradually apply pressure to
the attachment and press the valve seat insert into
place.
Note:
Do not apply an excessive amount of pressure with
the bench press. Damage to the valve seat insert
will result.
Valve Seat Insert Correction
1. Remove the carbon from the valve seat insert surface.
2. Use a valve cutter (15°, 45°, and 75° blades) to mini-
mize scratches and other rough areas. this will bring
the contact width back to the standard value.
Remove only the scratches and rough areas. Do not
cut away too much. Take care not to cut away un-
blemished areas of the valve seat surface.
Inlet
mm(in)
2.2 (0.0866)
Standard Limit
Exhaust1.7 (0.0669)
2.5 (0.0984) 2.0 (0.0787)

6A Ð 12 ENGINE MECHANICAL
3. Visually inspect both ends of the push rod for exces-
sive wear and damage. The push rod must be re-
placed if these conditions are discovered during
inspection.
REASSEMBLY
6. Valve Guide
·Apply engine oil to the outside of the valve guide.
Using special tool, drive in a new valve guide from
the cmashft side.
Valve guide replacer: 9-8523-1212-0
5. Valve Stem Oil Seal
·Using special tool, drive in a new oil seal
Oil special tool, drive in anew oil seal
Oil seal installer: 5-8840-2033-0
4. Valve
·Apply engine oil to the outside of the valve stem.
Push Rod Curvature
1. Lay the push rod on a surface plate.
2. Roll the push rod along the surface plate and measure
the push rod cuvature with a thickness gauge.
If the mesure value exceeds the specified limit, the
push rod must be replaced.
NOTE:
Use an adjustable valve cutter pilot.
Do not allow the valve cutter pilot to wobble inside the
valve guide.
3. Apply abrasive compound to the valve seat insert
surface.
4. Insert the valve into the valve guide.
5. Turn the valve while tapping it to fit the valve seat
insert.
6. Check that the valve contract width is correct.
7. Check that the valve seat insert surface is in contact
with the entire circumference of the valve.
mm(in)
0.3 (0.0118) Push Rod Curvature Limit
degree
45 Valve Seat Angle

ENGINE MECHANICAL 6A Ð 27
NOTE:
Do not allow the crankshaft to rotate.
9) Remove the main bearing caps.
10) Measure the plastigage width and determine the
oil clearance. If the oil clearance exceeds the
specified limit, replace the main bearings as a set
and/or replace the crankshaft.
11) Clean the plastigage from the bearings and the
crankshaft.
Remove the crankshaft and the bearings.
3. Run-out
1) Carefully set the crankshaft on the V-blocks.
Slowly rotate the crankshaft and measure the
runout. If the crankshaft runout exceeds the
specified limit, the crankshaft must be replaced.
Measure the diameter and the uneven wear of
main journal and crank pin.
If the crankshaft wear exceeds the specified limit,
crankshaft must be replaced.
Standard Limit
mm(in.)
0.031 – 0.063
(0.0012 – 0.0025)0.11 (0.0043)
Standard Limit
mm(in)
0.05 (0.0020)
or less0.08 (0.0031) Run-Out
Standard Limitmm(in)
Main journal
diameter69.91
(2.7524)
69.917-69.932
(2.7526-2.7532)
Crank pin
diameter52.90
(2.0843) 52.915-52.930
(2.0833-2.0839)
Uneven
wear limit
0.05
(0.0020)
or less
0.08
(0.0031)

ENGINE MECHANICAL 6A Ð 39
3. Measure the oil clearance between the connecting
rod and the crankshaft by:
1) Remove the connecting rod cap nuts and the rod
caps.
Arrange the removed rod caps in the cylinder
number order.
2) Clean the rod bearings and the crankshaft pins.
3) Carefully check the rod bearings.
If even one bearing is found to be damaged or
badly worn, the entire bearing assembly must be
replaced as a set. Reinstall the bearings in their
original positions.
Apply plastigage to the crank pin.
4) Reinstall the rod caps to their original positions.
5) Tighten the cap nuts in 2 steps, using angular
tightening method as shown in the following
specifications.
NOTE:
Do not allow the crankshaft to rotate.
N·m (kg·m/lb·ft)
45¡ ~ 60¡ 1st step 2nd step
29 (3.0/22)
6) Remove the rod caps.
7) Measure the width of the plastigage and determine
the oil clearance. If the oil clearance exceeds the
limit, replace the rod bearings as a set.
8) Clean the plastigage from the bearings and the
crankshaft pins.
REASSEMBLY
10. Connecting Rod
9. Piston
8. Piston Pin
·Apply a coat of engine oil to the piston pin and the
piston pin hole.
7. Piston Pin Snap Ring
·Apply a thin coat of engine oil to the piston pin.
Try to insert the piston pin into the piston pin hole
with normal finger pressure.
Weigh each piston and connecting rod assembly.
Select piston and connecting rod combinations so
that the weight variation of the different assemblies
is held within the specified limits.
Variance in weight
after assemblyLess than 3
(0.1058)g (oz)
Standard Limit
0.029 (0.0011) – 0.083 (0.0033) 0.100 (0.0039)
mm (in)
NOTE:
When changing piston/connecting rod combinations, do
not change the piston/piston pin combination.

6A2 Ð 32 4JG2-NA/4JG2-TURBO ENGINE
5. Vacuum Hose
6. Crankcase
·Remove crankcase fixing bolts two fixing bolts for
rear oil seal arch parts on crankcase could be
removed extention universal joint box wrench.
·Remove crankcase by using crankcase seal cutter
to shear sealant off and remove crankcase.
Oil seal cutter: 5-8840-2153-0
NOTE
·DonÕt ply crankcase or you may distort sealing
surface.
·Distorted or damaged crankcase should not by
used.
INSTALLATION
6. Crankcase
·Completely remove all sesidual sealant, lubricant
and moisture from the sealing surface of
crankcase and cylinder block.
·Apply a correct width bead of sealant (TB-1207C or
its equivalent) to contact surface of crankcase
there must be no gaps in the bead.
·Install crankcase with cylinder-block, and tighten
fixing bolts to the specified torque.
5. Vacuum Hose
4. Oil Level Gauge Guide Tube
·Install guide tube to the specified torque.
·Connect blow by hose to guide tube.
3. Oil Pipe Clip Bolts: Vacuum Pump
·Tighten oil pipe clip fixing bolts to the specified
torque.
2. Oil Return Pipe: Turbo.
·Tighten fixing nuts to crankcase to the specified
torque.
1. Transmission Housing Bolts
·Pour engine oil into engine.
·Install battery ground cable.
·Start the engine and check for oil leakage from
crankcase.
19 (1.9/14)N·m (kg·m/lb·ft)
19 (1.9/14)N·m (kg·m/lb·ft)
19 (1.9/14)N·m (kg·m/lb·ft)
8 (0.8/69)N·m (kg·m/lb·in)

6A – 6 ENGINE MECHANICAL
SERVICE STANDARD
Enginemm (in)
Parts Items Service standard Service limit Remarks
Cylinder Head
Valve Spring
Valve and
Valve guide
Camshaft0.075 (0.0030) or less
95.0 (3.740)
45.7 (1.8)
—
241 (54.2)
6.959 – 6.977
(0.27 –0.272)
6.692 –6.970
(0.271 –0.272)
0.023 –0.056
(0.0009 – 0.0022)
0.03 – 0.063
(0.0011 – 0.0024)
8.0 (0.312)
1.1 (0.0433)
1.2 (0.0472)
1.2 (0.0472)
45°
2.1 (0.0827)
2.1 (0.0827)
0.08 (0.00314)
46.67 (1.8374)
46.77 (1.8413)
29.939 – 29.960
(1.167 – 1.168)
0.02 (0.0008) or less
0.40 – 0.082
(0.0016 – 0.0032)0.50 (0.0197)
—
44.8 (1.765)
1.6 (0.063)
210 (47.22)
6.92 (0.270)
6.90 (0.269)
0.19 (0.0074)
0.20 (0.0079)
—
1.6 (0.0630)
1.1 (0.0433)
1.1 (0.0433)
—
2.6 (0.1024)
2.6 (0.1024)
2.0 (0.00797)
46.57 (1.8335)
46.67 (1.8374)
29.84 (1.1748)
0.10 (0.0039)
0.12 (0.0047)Cannot be
reground Cylinder head lower surface for flatness
Cylinder head height
Free height
Squareness
Spring tension (when assembled) N(lb)
Diameter of Valve stem IN
EX
Valve and valve guide clearance IN
EX
Valve guide upper end height
(Measured from the Cylinder head upper
face)
Valve guide margin
Valve thickness IN
EX
Valve seat contact surface angle
Valve seat contact width IN
EX
End play
Cam lobe height IN
EX
Journal diameter
Runout
Camshaft oil clearance

6A – 50 ENGINE MECHANICAL
NOTE: Do not allow the camshaft to rotate.
6) Remove the camshaft bracket and measure the
plastigauge width and determine the oil
clearance. If the oil clearance exceeds the
specified limit, replace the camshaft carrier
and/or camshaft.
Oil clearance.
Standard: 0.040 – 0.082 mm (0.0016 – 0.0032 in)
Limit: 0.12 mm (0.0047 in)
7) Clean the plastigauge from the camshaft bracket
and camshaft carrier.
5. Camshaft thrust clearance.
1) Clean the camshaft, camshaft bracket and
camshaft carrier.
2) Put camshaft carrier on the cylinder head.
3) Put camshaft on the camshaft carrier.
4) Put plastigauge on the camshaft journal.5) Install camshaft bracket to original position and
tighten bolts to specified torque in the numerical
order shown in the illustration.
Torque: A; 22 N·m (2.2 kg·m/15.9 lb ft)
B; 38 N·m (3.9 kg·m/28.2 lb ft)
C; 22 N·m (2.2 kg·m/15.9 lb ft)
D; 38 N·m (3.9 kg·m/28.2 lb ft)
6) Use a dial indicator to measure the camshaft
thrust clearance. If the camshaft thrust
clearance exceeds the specified limit, replace
the camshaft carrier and/or camshaft.
Camshaft thrust clearance
Standard: 0.1 mm (0.0002 in)
Limit: 0.2 mm (0.0078 in)
13
7
6
5
1215
2
3
10
9
20
8
19
2322
4
161
11 25
24
21
17
18
011RW041
014RW185
CC
D
B
CC
B
CC
D
CC
B
C
A AA A A A
AAAA
011RW035
13
7
6
5
1215
2
3
10
9
20
8
19
2322
4
161
11 25
24
21
17
18
011RW041