engine ISUZU KB P190 2007 Workshop Repair Manual

6D2-2 IGNITION SYSTEM



General Description
Ignition is done by the Ignition Module that fires.
Since the cylinder on exhaust stroke requires less energy to
fire its spark plug, energy from the ignition coils can be utilized
to fire the mating cylinder on compression stroke.
A notch in the timing disc on the crankshaft activates the crank
angle sensor which then sends information such as firing order
and starting timing of ignition coil to the ECM.
By receiving signals such as crank position, engine speed,
water temperature and Manifold Absolute Pressure (MAP), the
ECM controls the ignition timing.




Service Precaution
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.



Diagnosis
Refer to Section Drivability and Emissions for the diagnosis to
electronic ignition system (El system).





Ignition Coil
Removal
1. Disconnect battery ground cable.
2. Disconnect the Ignition coil connector.
3. Remove the ignition coil.



Installation
1. Install the ignition coil.
Connect ignition coil connector and ignition coil, then tighten bolt to the specified torque.
Torque: 20 N ⋅m (2.0 kgf ⋅m)
2. Connect battery ground cable.


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ISUZU KB P190 2007

IGNITION SYSTEM 6D2-3







Spark Plug
Removal
1. Remove spark plugs.
Inspection and Repair
The spark plug affects entire engine performance and
therefore its inspection is very important.
• Check electrode and insulator for presence of cracks, and
replace if any.
• Check electrode for wear, and replace if necessary.
• Check gasket for damage, and replace if necessary.
• Measure insulation resistance with an ohmmeter, and
replace if faulty.
• Adjust spark plug gap to 1.0 - 1.1 mm (0.027 in) - 0.8 mm
(0.031 in).
• Check fuel and electrical systems if spark plug is extremely
dirty.
• Use spark plugs having low heat value (hot type plug) if fuel
and electrical systems are normal.
• Use spark plugs having high heat value (cold type plug) i
f
insulator and electrode are extremely burned.


Sooty Spark Plugs
Much deposit of carbon or oil on the electrode and insulator of
spark plug reduces the engine performance.
Possible causes:
• Too rich mixture
• Presence of oil in combustion chamber
• Incorrectly adjusted spark plug gap


Burning Electrodes
This fault is characterized by scorched or heavily oxidized
electrode or blistered insulator nose.
Possible causes:
• Too lean mixture
• Improper heat value




Measuring Insulation Resistance
• Measure insulation resistance using a 500 volt megaohm
meter.
• Replace spark plugs if measured value is out of standard.
Insulation resistance: 50 M Ω or more


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6D2-4 IGNITION SYSTEM


Cleaning Spark Plugs
• Clean spark plugs with a spark plug cleaner.
• Raise the ground electrode to an angle of 45 to 60 degrees.
if electrode is wet, dry it gefore cleaning.
•
After spark plug is thoroughly cleaned, check insulator for
presence of cracks.




• Clean threads and metal body with a wire brush.
• File the electrode tip if electrode is extremely worn.
• Bend the ground electrode to adjust the spark plug gap.



Installation
1. Spark plugs
• Tighten spark plugs to the specified torque.
Torque: 20 N ⋅m (2.0 kgf ⋅m)












Crankshaft Angle Sensor
Removal
1. Disconnect battery ground cable
2. Disconnect the wiring connector from crankshaft angle sensor.
3. Remove crankshaft angle sensor from cylinder block.
Installation
1. Install crankshaft angle sensor into the cylinder block.
Before installation, apply small amount of engine oil to the O-ring.
Torque: 6 N ⋅m (0.6 kgf ⋅m)
2. Reconnect wiring connector to crankshaft angle sensor.



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IGNITION SYSTEM 6D2-5
Main Data and Specifications General Specifications
Ignition System
Ignition Form Electronic Ignition System (El system) with Crankshaft angle Sensor
Spark Plug
Type
No. of Coils and Type Coil Location Torque Electronic Spark Control
2 Solid State
Engine-mounted
20 N ⋅m (2.0 kgf ⋅m)


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6D3-2 STARTING AND CHARGING SYSTEM


Starting System
General Description
Cranking Circuit
The cranking system consists of a battery, starter, starter
switch, starter relay, etc. These main components are
connected.
Starter
The cranking system employs a magnetic type reduction
starter in which the motor shaft is also used as a pinion shaft.
W hen the starter switch is turned on, the contacts of magnetic
switch are closed, and the armature rotates. At the same time,
the plunger is attracted, and the pinion is pushed forward by
the shift lever to mesh with the ring gear.
Then, the ring gear runs to start the engine. W hen the engine
starts and the starter switch is turned off, the plunger returns,
the pinion is disengaged from the ring gear, and the armature
stops rotation. W hen the engine speed is higher than the
pinion, the pinion idles, so that the armature is not driven.




Service Precaution
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.

Diagnosis
Condition Possible cause Correction
Starter does not run Charging failure Repair charging system
Battery Failure Replace Battery
Terminal connection failure Repair or replace terminal connector
and/or wiring harness
Starter switch failure Repair or replace starter switch
Starter failure Repair or replace starter


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6D3-8 STARTING AND CHARGING SYSTEM
General On-Vehicle Inspection
The operating condition of charging system is indicated by the
charge warning lamp. The warning lamp comes on when the
starter switch is turned to "ON" position. The charging system
operates normally if the lamp goes off when the engine starts.
If the warning lamp shows abnormality or if undercharged or
overcharged battery condition is suspected, perform diagnosis
by checking the charging system as follows:
1. Check visually the belt and wiring connector.
2. W ith the engine stopped, turn the stator switch to "ON" position and observe the warning lamp.
If lamp does not come on:
Disconnect wiring connector from generator, and ground the terminal "L" on connector side.
If lamp comes on:
Repair or replace the generator.




Generator
Removal
1. Disconnect battery ground cable.
2. Move drive belt tensioner to loose side using wrench then remove drive belt.
3. Disconnect terminal "B" wiring connector and connector.
4. Remove generator assembly.

Generator Power and Circuit Diagram


Inspection
Legend
1 Load resistor, set parallel to battery
2 Battery
3 Voltmeter
4 Ammeter
5 Ignition Lock
6 Charge Telltale
7 Generator

1. Disconnect battery.
2. Close off connecting cable from alternator terminal "B+".
3. Set ammeter (measuring range 100A) in disconnected line.
4. Connect controllable load resistor to battery terminal.
5. Set resistor in front of connection to "O"; connect first to battery, then to resistor.
6. Connect tachometer.
7. Connect oscilloscope according to manufacturer's instructions.
8. Connect battery.
9. Start engine and read off resulting current at various engine speeds.


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STARTING AND CHARGING SYSTEM 6D3-11
Warning
Do not reverse S and L connections as this will destroy the
warning lamp circuit of the regulator.
Ensure good electrical contact beween generator earth and
battery negative,

Operation
W ith the Iginiton switch turnded "ON", current is supplied via
the warning lamp to the "L" terminal of the regulator. Base
current is fed to T15 causing it to turn on, current then flows
from B+ through the rotor winding via the regulator brushes
and the collector emitter junction of T15 to earth completing
the circuit. The current in the rotor causes a magnetic field
between adjacent poles to be created, this field is rotated and
cuts the windings of the stator at right angles inducing a
voltage into them.
As the speed is increased this induced voltage increases and
results in curent being rectified in the 3 phase diode bridge and
supplied as DC to the B+ output and hence to the battery.
W hen the voltage at the B+ terminal of the battery reaches
around 14.2 volts, this voltage is monitored by the "S" lead and
turns the regulator Hybrid base current to T15 OFF removing
rotor current, resulting in a decrease in output voltage to below
the regulating voltage, T15 base current turns ON and the
whole cycle is repeated very rapidly.
D38 protects T15 and the regulator against the back voltage
developed across the rotor winding when T15 turns OFF.
The new generated EP regulators incorporate current limiting
in the warning lamp circuit.

Backup Regulation
The EP regulator will limit the output voltage to a safe level
should either the main B+ cable or the battery sense wire
become decoupled, the output voltage will be slightly above the
normal setting(1-3 volts).

Start up phase
W hen the Iginition switch is turned on and the engine is not
running, the current to the rotor is reduced by switching it on
and off at a 50% duty cycle, the frequency is approximately 4
KHz and may be audible at times.
This is quite normal, once the engine is started normal
regulation commences.

Warning lamp failure
Should the warning lamp fail, the generator will self excite by
deriving a small current from the phase connecion allowing the
voltage to build up to regulating level.
Note: no filed current will flow when the engine is cranking.


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STARTING AND CHARGING SYSTEM 6D3-13
5. During current output tests please make sure that the
ammeter is securely connceted into the charge circuit.
6. Some battery powered timing lights can produce high transient voltages when connected or disconnected. Onl
y
disconnect or connect timing lights when the engine is
switched off.
7. Make sure the warning lamp circuit is functioning normall
y
before commencing tests.
8. Battery isolation switches must only be operated when the engine is stopped.
9. To protect the charging system when using 240 volt chargers it is recommeneded that the battery is
disconnected whilst charging.
10. Due to the very low resistance value of the stator winding it may not be possible to obtain accurate readings without
special equipment.
11. 12 volts must never be connected to the "L" terminal of the regulator as this will damage the lamp driver circuit.
12. No loads apart from the warning lamp can be connected to the "L" termainal. The "W " terminal is provided for this
purpose.

Disassembly
1. Mark the relative positions of the end housings in relation to the stator assembly to aid reassembly. Use a permanent
marking pen do not use centre punched as this can cause
misalignmnet of the housings.
2. Remove the EP regulator from the slipring end housing b
y
removing the two screws. Tilt the regulator slightly from the
plug connection until the regulator clears the housing, then
lift clear.
3. Remove the four through bolts.
4. Carefully remove the stator assembly along with the slipring end housing taking care not to put strain on the stator wires.
5. To disconnect the stator from the rectifier assembly, grasp the stator wires close to the wire loop with a pair of long
nosed pliers, heat the joint with a soldering iron, when the
point becomes plastic apply a slight twisting motion to the
wires, then pull upwards to release the wires. Remove the
stator.
This procedure opens the wire loop to release the stato
r
connections easily.
6. To remove the rectifier remove the three retaining scre
w
and the B+ terminal nut and washers.

Note: the B+ bolt and the positive heatsink retaining screw are
fitted with mica insulating washers.
These must be discarded and replaced with new washers and
heatsink compound.


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STARTING AND CHARGING SYSTEM 6D3-19
Inspection
Generator
Before any in field testing can be undertaken it is important
that the battery's conditions is established and the terminals
are clean and tight.

Check the condition of the generator drive belt and ensure that
it is adjusted in accordance with the engine manufacturer's
recommnedations.

Battery conditions:
Note: This assessment may be difficult with maintenance free
assemblies.

Test the specific gravity of the individual cells the readings
should be within 10 points of each other, it is recommended
that the average SG should be 1.260 or higher.
A load test should be carried out to determine the ability of the
battery to supply and accept current. This is a good indicator
as to the general condition of the battery.
A load equal to the normal starting current should be placed
across the battery, the duration of this load test should not
exceed 10 seconds, during this time the terminal voltage
across the battery should not drop below 9.6 volts. Observe
each cell for signs of excessive gas liberation, usuall an
indication of cell failure.
If the battery test is clear proceed with the Generator tests as
follows.

Care should be taken when making the following connections.
It is recommended that the battery negative terminal be
disconnected before the test meters are connected, and
reconnecting the negative terminal when the meters are
inserted into the circuit under test. The warning lamp in the D+
circuit should not exceed 2 watts.

Regulating voltage test on the vehicle.
Connect a voltmeter to the generator, the positive lead to the
B+ terminal and the nagative lead to the generator casing.
Select the voltage range to suit the system, i.e. 20v for 12 volt
sysytems or 40v for 24 volt systems. Connect an ammeter in
series with the main output cable from the B+ terminal on the
generator, the range selected must be capable of reading the
maximum output from the generator.

Note the voltmeter reading before starting the engine. This
reading should increase when the engine is running indicating
generator output, start the engine and increase the engine
speed until the generator is running at 4000 rpm, switch on
vehicle loads of 5-10 A is indcated on the ammeter, the
voltmeter shoud read 14.0-14.2 v for a 12 volt system, for a 24
volt system the readings should be 5-10 A and 27.7-28.5 volts.


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6D3-20 STARTING AND CHARGING SYSTEM
Load regulation test
Increase the engine speed until the generator is running at
6000 rpm, increase the load to 90% of full output a decrease in
the regulating voltage should not exceed 0.50 volts for 12 v
and 0.70 v for 24 v regulators of the readings obtained in the
previous test. If so, the regulator is defective.

Generator output test at full load
Increase engine speed until the altenator is running at 6000
rpm, switch on electrical loads until the generator voltage
drops to 13.5 volts for 12 v systems and 26 volts for 24 v
systems, full outut should be obtained under these conditions.
It may be necessary to adjust engine speed to maintain
altenator speed. If sufficient electrical loads are not available a
carbon pile resistance can be connected across the battery
and adjusted until maximum output is obtained.

Keep the time for this test to a minimum to avoid undue
heating and high engine speeds.




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