POSITIVE CRANKCASE VENTILATION PCV SYSTEM ISUZU TF SERIES 2004 Workshop Manual

TROUBLESHOOTING 6 – 9
6. Overheating
Step Action Value(s) Yes No
1 Was the engine coolant level OK? —
Go to Step 2 Replenish the
coolant
2 Was the water leakage or the radiator restriction
found? (Include radiator cap) — Repair or
replace the
leakage part. Go to Step 3
3 Was the fan belt slippage found? — Tension or
replace the fan
belt. Go to Step 4
4 Was the fan clutch working completely? —
Go to Step 5 Replace the
fan clutch
assembly.
5 Was the oil leakage found from fan clutch? — Replace the
fan clutch
assembly Go to Step 6
6 Was the thermostat working normally? —
Go to Step 7 Replace the
thermostat.
7 Was the water pump working OK? —
Go to Step 8 Replace the
water pump
assembly.
8 Was the restriction by the foreign materials in the
cooling system found? For example, clog the water
hose between the cylinder body and radiator etc.. — Clean or
replace the
clog part. Go to Step 9
9 Was the water leakage found from the sealing cap
on the cylinder body? — Replace the
sealing cap or
replace the
cylinder body. Go to Step 10
10 Are any DTC stored? — Go to indicated
DTC. Solved

7. White Exhaust Smoke
Step Action Value(s) Yes No
1 Was the compression pressure OK? 3.0 MPa
(31.0 kg/cm2,
441 psi) at
200 rpm
Go to Step 2 Readjust the
valve clearance
or replace the
cylinder head
gasket or
cylinder liner or
piston or piston
ring or valve
and relation
parts.
2 Was the PCV (Positive Crankcase Ventilation) valve
working completely? —
Go to Step 3 Repair or
replace the
PCV valve.
3 Was the turbocharger working completely? —
Go to Step 4 Replace the
turbocharger.
4 Are any DTC stored? — Go to indicated
DTC Solved

6A – 2 ENGINE MECHANICAL
Disassembly ............................................................................................................... 6A- 47
Internal Parts........................................................................................................... 6A- 47
Major Components.............................................................................................. 6A- 47
Minor Components ............................................................................................. 6A- 56
Rocker Arm Shaft and Rocker Arm................................................................ 6A- 56
Cylinder Head .................................................................................................. 6A- 57
Piston and Connecting Rod ........................................................................... 6A- 59
Inspection and Repair................................................................................................ 6A- 61
Cylinder Head ......................................................................................................... 6A- 61
Rocker Arm Shaft and Rocker Arm ....................................................................... 6A- 68
Cylinder Body ......................................................................................................... 6A- 69
Camshaft ................................................................................................................. 6A- 77
Crankshaft and Bearing ......................................................................................... 6A- 79
Crankshaft Bearing Selection................................................................................ 6A- 83
Crankshaft Pilot Bearing........................................................................................ 6A- 85
Flywheel and Ring Gear ......................................................................................... 6A- 85
Piston....................................................................................................................... 6A- 86
Cylinder Head Gasket Selection............................................................................ 6A- 88
Connecting Rod ...................................................................................................... 6A- 90
Idler Gear Shaft and Idler Gear.............................................................................. 6A- 91
Timing Gear Case Cover ........................................................................................ 6A- 91
Reassembly ................................................................................................................ 6A- 93
Internal Parts........................................................................................................... 6A- 93
Minor Component ............................................................................................... 6A- 93
Rocker Arm Shaft and Rocker Arm................................................................ 6A- 93
Cylinder Head .................................................................................................. 6A- 94
Piston and Connecting Rod ........................................................................... 6A- 96
Positive Crankcase Ventilation (PCV) Valve ................................................. 6A- 99
Major Component................................................................................................ 6A- 101
Installation .................................................................................................................. 6A- 118
External Parts ......................................................................................................... 6A- 118
Lubrication System........................................................................................................ 6A- 126

6A-16 ENGINE MECHANICAL (6VE1 3.5L)
Symptom Possible Cause Action
Trouble in emission control system Heated Oxygen Sensor circuit open Correct or replace
Heated Oxygen Sensor defective Replace
Signal vacuum hose loosely fitted or
defective Correct or replace
EGR Valve circuit open or shorted Correct or replace
EGR Valve defective Replace
ECT Sensor circuit open or shorted Correct or replace
Canister Purge Valve circuit open or
shorted Correct or replace
Canister Purge Valve defective Replace
ECT Sensor defective Replace
Positive Crankcase Ventilation (PCV)
valve and hose clogged Correct or replace
Evaporator system 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

ENGINE DRIVEABILITY AND EMISSIONS 6E–1
ENGINE
CONTENTS
C24SE ENGINE DRIVEABILITY AND EMISSIONS
ABBREVIATIONS CHARTS ......................... 6E-6
ECM Circuit Diagram (1/2) ............................ 6E-11
ECM Circuit Diagram (2/2) ............................ 6E-12
GROUND POINT CHART - LHD G.EXP (1/4) 6E-13
GROUND POINT CHART - RHD G.EXP (1/4) 6E-17
LOCATION ................................................... 6E-21
CABLE HARNESS & CONNECTOR
LOCATION .............................................. 6E-23
CABLE HARNESS & CONNECTOR
LOCATION
LHD ................................... 6E-24
CABLE HARNESS & CONNECTOR
LOCATION
RHD ................................... 6E-25
CONNECTOR LIST ...................................... 6E-28
RELAY AND FUSE ....................................... 6E-30
RELAY AND FUSE BOX LOCATION
(LHD & RHD) ........................................... 6E-30
FUSE AND RELAY LOCATION (LHD & RHD) 6E-32
ECM WIRING DIAGRAM (1/9) ..................... 6E-33
ECM WIRING DIAGRAM (2/9) ..................... 6E-34
ECM WIRING DIAGRAM (3/9) ..................... 6E-35
ECM WIRING DIAGRAM (4/9) ..................... 6E-36
ECM WIRING DIAGRAM (5/9) ..................... 6E-37
ECM WIRING DIAGRAM (6/9) ..................... 6E-38
ECM WIRING DIAGRAM (7/9) ..................... 6E-39
ECM WIRING DIAGRAM (8/9) ..................... 6E-40
ECM WIRING DIAGRAM (9/9) ..................... 6E-41
ECM CONNECTOR PIN ASSIGNMENT &
OUTPUT SIGNAL .................................... 6E-42
GENERAL DESCRIPTION FOR ECM AND
SENSORS ............................................... 6E-48
Engine Control Module (ECM) ................... 6E-48
Manifold Absolute Pressure (MAP) Sensor 6E-48
Throttle Position Sensor (TPS) .................. 6E-49
Idle Air Control (IAC) Valve ....................... 6E-49
Crankshaft Position (CKP) Sensor ............ 6E-50
Knock Sensor (KS) .................................... 6E-50
Engine Coolant Temperature (ECT) Sensor 6E-50
Intake Air Temperature (IAT) Sensor ........ 6E-51
Vehicle Speed Sensor (VSS) .................... 6E-51
Heated Ox ygen (O
2) Sensor ..................... 6E-51
GENERAL DESCRIPTION FOR FUEL
METERING .............................................. 6E-52Battery Voltage Correction Mode ............... 6E-52
Clear Flood Mode ...................................... 6E-52
Deceleration Fuel Cutoff (DFCO) Mode .... 6E-52
Engine Speed/ Vehicle Speed/ Fuel Disable
Mode ........................................................ 6E-52
Acceleration Mode ..................................... 6E-52
Fuel Cutoff Mode ....................................... 6E-52
Starting Mode ............................................ 6E-52
Run Mode .................................................. 6E-52
Fuel Metering System Components .......... 6E-53
Fuel Injector ............................................... 6E-53
Fuel Pressure Regulator ............................ 6E-53
Fuel Rail ..................................................... 6E-53
Fuel Pump Electrical Circuit ....................... 6E-53
Thottle Body Unit ....................................... 6E-53
GENERAL DESCRIPTION FOR ELECTRIC
IGNITION SYSTEM ................................. 6E-54
Spark Plug ................................................. 6E-54
GENERAL DESCRIPTION FOR EVAPORATIVE
EMISSION SYSTEM ............................... 6E-57
EVAP Emission Control System Purpose .. 6E-57
EVAP Emission Control System Operation 6E-57
System Fault Detection .............................. 6E-57
POSITIVE CRANKCASE VENTILATION (PCV)
SYSTEM .................................................. 6E-59
Crankcase Ventilation System Purpose .... 6E-59
A/C CLUTCH DIAGNOSIS ........................ 6E-60
A/C Clutch Circuit Operation ...................... 6E-60
A/C Clutch Circuit Purpose ........................ 6E-60
A/C Request Signal ................................... 6E-60
ISUZU STRATEGY BASED DIAGNOSTICS 6E-61
Overview .................................................... 6E-61
STRATEGY BASED DIAGNOSTICS CHART 6E-61
Diagnostic Thought Process ...................... 6E-62
1. Verify the Complaint .............................. 6E-62
2. Perform Preliminary Checks .................. 6E-62
3. Check Bulletins and Troubleshooting Hints 6E-63
4. Perform Service Manual Diagnostic Checks 6E-63
5a and 5b. Perform Service Manual Diagnostic
Procedures .............................................. 6E-63
5c. Technician Self Diagnoses .................. 6E-63
5d. Intermittent Diagnosis .......................... 6E-64

ENGINE DRIVEABILITY AND EMISSIONS 6E–59
POSITIVE CRANKCASE VENTILATION
(PCV) SYSTEM
Crankcase Ventilation System Purpose
The crankcase ventilation system is used to consume
crankcase vapors in the combustion process instead of
venting them to the atmosphere. Fresh air from the
throttle body is supplied to the crankcase and mixed
with blow-by gases. This mix ture is then passed through
the positive crankcase ventilation (PCV) port into the
intake manifold.
While the engine is running, ex haust gases and small
amounts of the fuel/air mix ture escape past the piston
rings and enter the crankcase. these gases are mixed
with clean air entering through a tube from the air intake
duct.
During normal, part-throttle operation, the system is
designed to allow crankcase gases to flow through the
PCV hose into the intake manifold to be consumed by
normal combustion.
A plugged positive crankcase ventilation port or PCV
hose may cause the following conditions:
Rough idle.
Stalling or slow idle speed.
Oil leaks.
Sludge in the engine.
A leaking PCV hose would cause:
Rough idle.
Stalling.
High idle speed.