2007 ISUZU KB P190 ignition

6-4 ENGINE DIAGNOSIS (C24SE)
Rough Engine Idling or Engine Stalling
Condition Possible cause Correction
Trouble in fuel injection system Idle air control valve defective Replace
Throttle shutting off incomplete Correct or replace
Throttle position sensor circuit
open or shorted Correct or replace

Fuel injector circuits open or
shorted Correct or replace

Fuel injectors damaged Replace
Fuel pump relay defective Replace
Manifold Absolute Pressure
Sensor cable disconnected or
broken Correct or replace

Manifold Absolute Pressure
Sensor defective Replace

Engine Coolant Temperature
Sensor cable disconnected or
broken Correct or replace

Engine Coolant Temperature
Sensor defective Replace

Intake Air Temperature sensor
cable disconnected or broken Correct or replace

Intake Air Temperature sensor
defective Replace

Knock Sensor (KS) circuits open
or shorted Correct or replace
KS
defective Replace
KS Module circuits open or
ground Correct or replace

KS Module defective Replace
Vehicle Speed Sensor circuit open
or shorted Correct or replace

Vehicle Speed Sensor defective Replace
Trouble in emission control
system Engine Control Module defective Replace

Canister purge solenoid circuit
open Correct

Canister purge solenoid defective Replace
Evaporative Emission Canister
Purge control valve defective Replace

Trouble in ignition system Refer to Hard Start
Troubleshooting Guide
Others Engine lacks compression Refer to Hard Start
Troubleshooting Guide
Valve incorrectly seated Lap valve
Air Cleaner Filter clogged Replace filter element
Valve timing incorrect Readjust
Idle air control valve broken Replace


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ISUZU KB P190 2007

ENGINE DIAGNOSIS (C24SE) 6-5
Rough Engine Running
Condition Possible cause Correction
Engine misfires regularly Ignition coil layer shorted Replace
Spark plugs fouling Clean or install hotter type plug
Spark plug(s) insulator nose
leaking Replace

Spark plug wire incorrect Connect properly or replace
Fuel injector(s) defective Replace
Engine control module faulty Replace
Engine knocks regularly Spark plugs running too hot Install colder type spark plugs
Powertrain control module faulty Replace
Engine lacks power Spark plugs fouled Clean
Spark plug wire incorrect Connect properly or replace
Fuel injectors defective Replace
Manifold Absolute Pressure
(MAP)
Sensor or Manifold Absolute
Pressure Sensor circuit defective Correct or replace

Engine Coolant Temperature
Sensor or Engine Coolant
Temperature Sensor circuit
defective Correct or replace

Engine Control Module faulty Replace
Intake Air Temperature Sensor or
Intake Air Temperature Sensor
circuit defective Correct or replace

Throttle Position Sensor or
Throttle Position Sensor circuit
defective Correct or replace

Knock Sensor or Knock Sensor
circuits defective Correct or replace

Knock Sensor Module or Knock
Sensor Module circuits defective Correct or replace


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ISUZU KB P190 2007

ENGINE DIAGNOSIS (C24SE) 6-7
Engine Lacks Power
Condition Possible cause Correction
Trouble in fuel system Fuel Pressure Control Valve not
working normally Replace

Fuel injector clogged Clean or replace
Fuel pipe clogged Clean
Fuel filter clogged or fouled Replace
Fuel pump drive circuit not
working normally Correct or replace

Fuel tank not sufficiently breathing
due to clogged Evaporative
Emission Control System circuit Clean or replace

Water in fuel system Clean
Inferior quality fuel in fuel system Use fuel of specified octane rating
Engine Control Module supplied
poor voltage Correct circuit

Throttle Position Sensor cable
disconnected or broken Correct or replace

Throttle Position Sensor defective Replace
Manifold Absolute Pressure
Sensor not working normally Replace

Intake Air Temperature sensor not
working normally Replace

Engine Coolant Temperature
Sensor circuit open or shorted Correct or replace

Engine Coolant Temperature
Sensor defective Replace

Engine Control Module defective Replace
Trouble in intake or exhaust
system Air Cleaner Filter clogged Replace filter element

Air duct kicked or flattened Correct or replace
Ignition failure
- Refer to Hard Start
Troubleshooting Guide
Heat range of spark plug
inadequate Install spark plugs of adequate
heat range
Electronic Ignition System with
module Replace


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ISUZU KB P190 2007

6-10 ENGINE DIAGNOSIS (C24SE)
Troubleshooting Procedure
Condition Possible cause Correction
Piston pin noise
(Piston makes noise each time it
goes up and down) Piston pin or piston pin hole worn Replace piston, piston pin and
connecting rod assy

Troubleshooting Procedure
The slapping sound stops when spark plug on bad
cylinder is shorted out.
Condition Possible cause Correction
Timing belt noise Timing belt tension is incorrect Replace pusher or adjust the
tension pulley or replace timing
belt
Tensioner bearing defective Replace
Timing belt defective Replace
Timing wheels defective Replace
Timing belt comes in contact with
timing cover Replace timing belt and timing
cover
Valve noise Valve and valve guide seized Replace valve and valve guide
Valve spring broken Replace
Valve seat off-positioned Correct
Crankshaft noise Crankshaft end play excessive
(noise occurs when clutch is
engaged) Replace thrust bearing
Engine knocking
Preignition due to use of spark
plugs of inadequate heat range Install Spark Plugs of adequate
heat range
Fuel too low in octane rating Replace fuel
Wide Open Throttle enrichment
system failure Refer to Section 6E

Selection of transmission gear
incorrect Caution operator or incorrect gear
selection
Engine overheating Refer to "Engine Lacks Power"
Others Water pump defective Replace
V-belt slipping Adjust tension of V-belt or replace
V-belt


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ISUZU KB P190 2007

ENGINE DIAGNOSIS (C24SE) 6-11
Abnormal Combustion
Condition Possible cause Correction
Trouble in fuel injection system Fuel pressure control valve
defective Replace

Fuel filter clogged Replace
Fuel pump clogged Clean or replace
Fuel tank or fuel pipe clogged Clean or replace
Fuel injector clogged Clean or replace
Fuel pump relay defective Replace
Power supply cable for fuel pump
loosely connected or defective Reconnect, correct or replace

Manifold Absolute Pressure
Sensor circuit open or shorted Correct or replace

Manifold Absolute Pressure
Sensor defective Replace

Engine Coolant Temperature
(ECT) Sensor circuit open or
shorted Correct or replace

ECT Sensor defective Replace
Throttle Position Sensor
adjustment incorrect Reconnect

Throttle Position Sensor defective Replace
Throttle Position Sensor
connector loosely connected Reconnect

Vehicle Speed Sensor cable
loosely connected or defective Correct or replace

Vehicle Speed Sensor loosely
fixed Fix tightly

Vehicle Speed Sensor in wrong
contact or defective Replace

Engine Control Module cable
loosely connected or defective Correct or replace
Trouble in emission control
system Heated Oxygen Sensor circuit
open (If applicable) Correct or replace

Heated Oxygen Sensor defective
(If applicable) Replace

Signal vacuum hose loosely fitted
or defective Correct or replace

ECT Sensor circuit open or
shorted Correct or replace

ECT Sensor defective Replace
Evaporative Emission Control
system (If applicable) Refer to Section 6E
Trouble in ignition system
- Refer to "Engine Lacks Power"
Trouble in cylinder head parts Carbon deposits in combustion
chamber Remove carbon

Carbon deposit on valve, valve
seat and valve guide Remove carbon


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ISUZU KB P190 2007

ENGINE DIAGNOSIS (C24SE) 6-13
Fuel Consumption Excessive
Condition Possible cause Correction
Trouble in fuel system Mixture too rich or too lean due to
trouble in fuel injection system Refer to "Abnormal Combustion"

Fuel cut function does not act Refer to "Abnormal Combustion"
Trouble in ignition system Misfiring or abnormal combustion
due to trouble in ignition system Refer to Hard Start or Abnormal
Combustion Troubleshooting
Guide
Others Engine idle speed too high Reset Idle Air Control Valve
Returning of accelerator control
sluggish Correct

Fuel system leakage Correct or replace
Clutch slipping Correct
Brake drag Correct
Selection of transmission gear
incorrect Caution operator of incorrect gear
selection
Oil Problems
Condition Possible cause Correction
Oil pressure too low Wrong oil in use Replace with correct engine oil
Relief valve sticking Replace
Oil pump not operating properly Correct or replace
Oil pump strainer clogged Clean or replace strainer
Oil pump worn Replace
Oil pressure gauge defective Correct or replace
Crankshaft bearing or connecting
rod bearing worn Replace
Oil contamination
Wrong oil in use Replace with new engine oil
Oil filter clogged Replace oil filter
Cylinder head gasket damage Replace gasket
Burned gases leaking Replace piston and piston rings or
rebore cylinders
Oil not reaching valve system Oil passage in cylinder head or cylinder body clogged Clean or correct

Engine Oil Pressure Check
1. Check for dirt, gasoline or water in the engine
oil.
a. Check the viscosity of the oil.
b. Change the oil if the viscosity is outside the specified standard.
c. Refer to the "Maintenance and Lubrication" section of this manual.
2. Check the engine oil level. The level should fall somewhere between the
"ADD" and the "FULL" marks on the oil level
dipstick.
If the oil level does not reach the "ADD" mark on
the oil level dipstick, engine oil must be added.
3. Remove the oil pressure unit.
4. Install an oil pressure gauge.
5. Start the engine and allow the engine to reach normal operating temperature (About 80 °C).
6. Measure the oil pressure.
Oil pressure should be:
150 kPa(21.8 psi) at idle speed.
7. Stop the engine.
8. Remove the oil pressure gauge
9. Install the oil pressure unit.
10. Start the engine and check for leaks.

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ISUZU KB P190 2007

6A-2 ENGINE MECHANICAL (C24SE)
PAGE
Camshaft Housing, Check for Plance Surface ......................................................... 6A-39
Cylinder Head, Removal and Installation.................................................................. 6A-39
Cylinder Head, Disassemble and Assemble............................................................. 6A-42
Valve, Grind ................................................................................................................. 6 A-44
Valve Guide, Ream .................................................................................................... 6A-44
Valve Seating, Mill ...................................................................................................... 6A-45
Cylinder Head, Overhaul ............................................................................................ 6A-45
Flywheel....................................................................................................................... 6A-46
Starter Ring Gear(Manual Transmission) ................................................................. 6A-47
Seal Ring, Crankshaft................................................................................................. 6A-48
Seal Ring, Crankshaft Rear ........................................................................................ 6A-48
Oil Pan and Bearing Bridge ....................................................................................... 6A-49
OPERATIONS ON CRANK DRIVE ................................................................................... 6A-51 Con-Rod Bearing ........................................................................................................ 6A-51
Piston with Con-Rod................................................................................................... 6A-51
Con-Rod....................................................................................................................... 6A-52
Pistion Rings ............................................................................................................... 6A -53
OPERATIONS ON REMOVED ENGINE........................................................................... 6A-55 Crankshaft ................................................................................................................... 6 A-55
Bearing Free Play Measurement ............................................................................... 6A-57
Plastigage Method ...................................................................................................... 6A-57
Micrometer and gauge method.................................................................................. 6A-58
Bypass Valve ............................................................................................................... 6A- 59
Oil Filter ..................................................................................................................... .. 6A-59
Oil Pump ...................................................................................................................... 6A-59
Oil Pump Safety Valve ................................................................................................ 6A-60
Oil Pump(Overhaul) .................................................................................................... 6A-60
OPERATIONS ON OIL CIRCULATION ............................................................................ 6A-61 Cylinder Head Safety Valve ........................................................................................ 6A-61
OPERATIONS ON COOLING SYSYTEM ......................................................................... 6A-63 Cooling System, Check for Leakes ........................................................................... 6A-63
Cooling System, Fill Up and Bleed ............................................................................ 6A-63
Refill Coolant............................................................................................................... 6 A-64
Ignition Timing, Check ............................................................................................... 6A-64

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ISUZU KB P190 2007

ENGINE MECHANICAL (C24SE) 6A-3
PAGE
ENGINE EXTERNAL PARTS ........................................................................................... 6A-65 Radiator ....................................................................................................................... 6A-65
Thermostat .................................................................................................................. 6A -66
Water Pump ................................................................................................................. 6A- 66
Coating sealing surfaces with Silicone Grease ....................................................... 6A-67
Alternator ..................................................................................................................... 6A-67
Starter ........................................................................................................................ .. 6A-67
V-belt Tension of Alternator ....................................................................................... 6A-68
FUEL INJECTION SYSTEM ............................................................................................. 6A-70 Map Sensor ................................................................................................................. 6A- 70
Pressure Regulator..................................................................................................... 6A-70
ECM (Engine Control Module) ................................................................................... 6A-70
ECT............................................................................................................................ ... 6A-71
Idle Air Control(IAC) Valve ......................................................................................... 6A-71
Ignition Coil ................................................................................................................. 6A-71
Crank Position Sensor ............................................................................................... 6A-72
FUEL INJECTOR .............................................................................................................. 6A- 73
Knock Sensor.............................................................................................................. 6A-7 3
Oxygen Sensor............................................................................................................ 6A-74
Throttle Valve Position Sensor .................................................................................. 6A-74
Acclelerator Pedal and Cable .................................................................................... 6A-74
Air Cleaner Filter ......................................................................................................... 6A- 75
Spark Plug Thread ...................................................................................................... 6A-76
TECHNICAL DATA ........................................................................................................... 6A-77
Recommended Troque Values .................................................................................. 6A-88
SPECIAL SERVICE TOOL ............................................................................................... 6A-89


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ISUZU KB P190 2007