2004 ISUZU TF SERIES catalytic converter

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-363
Step Action Value (s) Yes No
14
Check the EVAP purge solenoid valve operation.
Is the valve operated normally?
- Verify repair &
Go to Step 17 Verify repair &
Go to Step 15
15
Check the exhaust system for a possible restriction:

Damaged or collapsed pipes.

Internal catalytic converter failure.
Was a problem found?
- Verify repair &
Go to Step 17 Go to Step 16
16
1. Remove excessive carbon buildup with a top
engine cleaner. Refer to the instructions on the top
engine cleaner can.
2. Perform the exhaust emission test.
Does the vehicle pass the test?
- System OK Go to Step 18
17
Perform the exhaust emission test.
Does the vehicle pass the test?
- System OK Go to Step 18
18
Check the fuel control Heated Oxygen Sensor
(HO2S). When monitored on the Tech 2, the HO2S
should respond quickly to different throttle positions. If
it doesn't check for silicon or other contaminates from
fuel or use of improper sealant. The sensors may have
a white powdery coating. Silicon contamination sends
a rich exhaust signal which causes the ECM to
command and excessively lean air/fuel mixture.
Was a problem found?
- Verify repair Go to Step 19
19
Monitor "B1S1 (Bank 1 Sensor 1) Status" and "B2S1
(Bank 2 Sensor 1) Status" on the Tech 2.
Is the "B1S1 (Bank 1 Sensor 1) Status" or "B2S1
(Bank 2 Sensor 1) Status" in the rich condition?
- Go to Step 20 Go to Step 21
20
Check items that can cause the engine to run rich.
Refer to DTC P0172 "O2 Sensor System Too Rich
(Bank 1)" or DTC P0175 "O2 Sensor System Too Rich
(Bank 2)".
Was a problem found?
- Verify repair Go to Step 22
21
Check items that can cause the engine to run lean.
Refer to DTC P0171 "O2 Sensor System Too Lean
(Bank 1)" or DTC P0174 "O2 Sensor System Tool
Lean (Bank 2)".
Was a problem found?
- Verify repair Go to Step 22
22
Check for the following engine mechanical problems
(refer to Engine Mechanical):

Low compression.

Leaking cylinder head gaskets.

Worn camshaft. -Sticking or leaking valves.

Valve timing. -Broken valve springs.
Was a problem found?
- Verify repair Go to Step 23

ENGINE EXHAUST (6VE1 3.5L) 6F-1
ENGINE
ENGINE EXHAUST (6VE1 3.5L)
CONTENTS

Service Precaution................................................. 6F-1
General Description............................................... 6F-2
Three Way Catalytic Converter and Center
Exhaust Pipe.......................................................... 6F-3
Three Way Catalytic Converter and Center
Exhaust Pipe and Associated Parts................ 6F-3
Removal............................................................... 6F-3

Installation............................................................. 6F-3
Exhaust Silencer and Rear Exhaust Pipe........... 6F-4
Exhaust Silencer and Rear Exhaust Pipe and
Associated Parts................................................. 6F-4
Removal................................................................ 6F-4
Installation............................................................. 6F-4
Main Data and Specifications................................ 6F-5


Service Precaution
WARNING: THIS VEHICLE HAS A SUPPLEMENTAL
RESTRAINT SYSTEM (SRS). REFER TO THE SRS
COMPONENT AND WIRING LOCATION VIEW IN
ORDER TO DETERMINE WHETHER YOU ARE
PERFORMING SERVICE ON OR NEAR THE SRS
COMPONENTS OR THE SRS WIRING. WHEN YOU
ARE PERFORMING SERVICE ON OR NEAR THE
SRS COMPONENTS OR THE SRS WIRING, REFE
R
TO THE SRS SERVICE INFORMATION. FAILURE TO
FOLLOW WARNINGS COULD RESULT IN
POSSIBLE AIR BAG DEPLOYMENT, PERSONAL
INJURY, OR OTHERWISE UNNEEDED SRS SYSTEM
REPAIRS.


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, o
r
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.

6F-2 ENGINE EXHAUST (6VE1 3.5L)
General Description



RTW46FLF000101
Legend (3) Three Way Catalytic Converter
(1) Front Exhaust Pipe LH (4) Center Exhaust Pipe
(2) Front Exhaust Pipe RH (5) Exhaust Silencer & Tail Pipe


When inspecting or replacing exhaust system
components, make sure there is adequate clearance
from all points on the underbody to prevent overheating
the floor pan and possible damage to the passenge
r
compartment insulation and trim materials.
Check complete exhaust system and nearby body
areas and rear compartment lid for broken, damaged,
missing or mispositioned parts, open seams, holes,
loose connections or other deterioration which could
permit exhaust fumes to seep into the rea
r
compartment or passenger compartment. Dust or water
in the rear compartment may be an indication of a
problem in one of these areas. Any faulty areas should
be corrected immediately.

Hangers
Various types of hangers are used to support exhaust
system(s). These include conventional rubber straps,
rubber rings, and rubber blocks.
The installation of exhaust system supports is very
important, as improperly installed supports can cause
annoying vibrations which can be difficult to diagnose.
Three Way Catalytic Converter
The three way catalytic converter is an emission control
device added to the exhaust system to reduce
pollutants from the exhaust gas stream.

ENGINE EXHAUST (6VE1 3.5L) 6F-3
CAUTION: The catalytic converter requires the use
of unleaded fuel only.
Periodic maintenance of the exhaust system is no
t
required. If the vehicle is raised for other service, it is
advisable to check the condition of the complete
exhaust system.
A dual bed monolith catalytic converter is used in
combination with three way catalytic converter.
Catalytic Converter Types:
Three way (Reduction/Oxidation) catalyst
The catalyst coating on the three way (reduction)
converter contains platinum and rhodium which lowers
the levels of nitrous oxide (NOx) as well as
hydrocarbons (HC) and carbon monoxide (Co).
Gasket
The gasket must be replaced whenever a new exhaust
pipe, muffler or catalytic converter is installed.

6F-4 ENGINE EXHAUST (6VE1 3.5L)
Three Way Catalytic Converter and Center Exhaust Pipe
Three Way Catalytic Converter and Center Exhaust Pipe and Associated Parts



RTW46FMF000201
Legend (4) Three Way Catalytic Converter LH
(1) Front Exhaust Pipe Fixing Nuts (5) Mounting Rubber
(2) O
2 Sensor (6) Exhaust Pipe Fixing Nuts
(3) Three Way Catalytic Converter RH (7) Center Exhaust Pipe


Removal
1. Disconnect battery ground cable.
2. Lift up the vehicle and support with suitable safety
stands.
3. Disconnect O
2 sensor harness connectors (2).
4. Remove the center exhaust pipe fixing nuts (6) and
the exhaust silencer fixing bolts, then remove the
center exhaust pipe and the mounting rubber.
5. Remove the front exhaust pipe fixing nuts (1) and
the mounting rubber, then remove the three way
catalytic converter (3) (4).
Installation
1. Install the three way catalytic converter (3) (4) and
the mounting rubber, and tighten the fixing nuts (1)
to the specified torque.
Torque : 67 N




m (6.8 kg




m/49 lb ft)
2. Install the center exhaust pipe and the mounting
rubbler, and tighten the fixing nuts (6) and bolts to
the specified torque.
Torque : 43 N




m (4.4 kg




m/32 lb ft)
3. Connect the O
2 sensor connectors (2).

ENGINE MECHANICAL (C24SE) 6A-77

Cooling System
Radiator

Type: Cross-flow

Radiator core surface in cm
2: 2000

Cooling system capacity (in litres): 7.2



Anti-freeze Mixture
Anti-freeze Mixture

Required
Quantity Up to-10




C
Quantity in litres Up to-20




C
Quantity in litres Up to-30




C
Quantity in litres Up to-40




C
Quantity of litres
(in litres) Water
(80%) Anti-
Freeze
(20%) Water
(66%) Anti-
Freeze
(34%) Water
(56%) Anti-
Freeze
(44%) Water
(48%) Anti-
Freeze
(52%)
7.2 5.7 1.5 4.7 2.5 4.0 3.2 3.4 3.8



Cooling System (continued)
Fan

Type Visco Clutch Fan
Number of blades 5
Distribution of blades asymmetric
Diameter mm



Radiator cap

Boiling point 123
C
Opening pressure kPa (bar) 120 to 135 (1.20 to 1.35)



Thermostat

Start of opening 92
C
Fully opened 107
C
Type Bypassed



Idle Speeds, CO Content, Ignition
Adjustment

Applicable System Idle speed in min-1 (rpm)
Manual CO content
in vol. % Ignition timing in CA BTDC (adjustment
ensues at able speed,
ignition marks must align) with TDC
sensor measuring instrument:
Closed Loop System 825 *<0.4 *** 8 to 12
Open Loop System 825
**1.0+0.2
-0.5 *** 8 to 12
Note) * CO content adjustment not applicable.
** CO content adjustment refer to Section 6E1 (W/O catalytic converter system)
*** Ignition timing adjustment not possible.

6E–52 ENGINE DRIVEABILITY AND EMISSIONS
GENERAL DESCRIPTION FOR FUEL
METERING
The fuel metering system starts with the fuel in the fuel
tank. An electric fuel pump, located in the fuel tank,
pumps fuel to the fuel rail through an in-line fuel filter.
The pump is designed to provide fuel at a pressure
above the pressure needed by the injectors.
A fuel pressure regulator in the fuel rail keeps fuel
available to the fuel injectors at a constant pressure.
A return line delivers unused fuel back to the fuel tank.
The basic function of the air/fuel metering system is to
control the air/fuel delivery to the engine. Fuel is
delivered to the engine by individual fuel injectors
mounted in the intake manifold.
The main control sensor is the heated ox ygen sensor
located in the ex haust system. The heated ox ygen
sensor reports to the ECM how much oxygen is in the
ex haust gas. The ECM changes the air/fuel ratio to the
engine by controlling the amount of time that fuel
injector is “On”.
The best mix ture to minimize exhaust emissions is 14.7
parts of air to 1 part of gasoline by weight, which allows
the catalytic converter to operate most efficiently.
Because of the constant measuring and adjusting of the
air/fuel ratio, the fuel injection system is called a “closed
loop” system.
The ECM monitors signals from several sensors in
order to determine the fuel needs of the engine. Fuel is
delivered under one of several conditions called “mode”.
All modes are controlled by the ECM.
Battery Voltage Correction Mode
When battery voltage is low, the ECM will compensate
for the weak spark by increasing the following:
The amount of fuel delivered.
The idle RPM.
Clear Flood Mode
Clear a flooded engine by pushing the accelerator pedal
down all the way. The ECM then de-energizes the fuel
injectors. The ECM holds the fuel injectors de-energized
as long as the throttle remains above 75% and the
engine speed is below 800 RPM. If the throttle position
becomes less than 75%, the ECM again begins to pulse
the injectors ON and OFF, allowing fuel into the
cylinders.
Deceleration Fuel Cutoff (DFCO) Mode
The ECM reduces the amount of fuel injected when it
detects a decrease in the throttle position and the air
flow. When deceleration is very fast, the ECM may cut
off fuel completely. Until enable conditions meet the
engine revolution less 1000 rpm or manifold absolute
pressure less than 10 kPa.
Engine Speed/ Vehicle Speed/ Fuel Disable
Mode
The ECM monitors engine speed. It turns off the fuel
injectors when the engine speed increases above 6000
RPM. The fuel injectors are turned back on when
engine speed decreases below 3500 RPM.
Acceleration Mode
The ECM provides ex tra fuel when it detects a rapid
increase in the throttle position and the air flow.
Fuel Cutoff Mode
No fuel is delivered by the fuel injectors when the
ignition is OFF. This prevents engine run-on. In addition,
the ECM suspends fuel delivery if no reference pulses
are detected (engine not running) to prevent engine
flooding.
Starting Mode
When the ignition is first turned ON, the ECM energizes
the fuel pump relay for two seconds to allow the fuel
pump to build up pressure. The ECM then checks the
engine coolant temperature (ECT) sensor and the
throttle position sensor to determine the proper air/fuel
ratio for starting.
The ECM controls the amount of fuel delivered in the
starting mode by adjusting how long the fuel injectors
are energized by pulsing the injectors for very short
times.
Run Mode
The run mode has the following two conditions:
Open loop
Closed loop
When the engine is first started, the system is in “open
loop” operation. In “Open Loop,” the ECM ignores the
signal from the heated oxygen sensor (HO2S). It
calculates the air/fuel ratio based on inputs from the TP,
ECT, and MAP sensors.
The system remains in “Open Loop” until the following
conditions are met:
The HO2S has a varying voltage output showing that
it is hot enough to operate properly (this depends on
temperature).
The ECT has reached a specified temperature.
A specific amount of time has elapsed since starting
the engine.
Engine speed has been greater than a specified RPM
since start-up.
The specific values for the above conditions vary with
different engines and are stored in the programmable
read only memory (PROM). When these conditions are
met, the system enters “closed loop” operation. In
“closed loop,” the ECM calculates the air/fuel ratio
(injector on-time) based on the signal from the HO2S.
This allows the air/fuel ratio to stay very close to 14.7:1.

6E–258 ENGINE DRIVEABILITY AND EMISSIONS
EXCESSIVE EXHAUST EMISSIONS OR ODORS SYMPTOM
DEFINITIONS: Vehicle fails an emission test. There is ex cessive “rotten egg” smell. (Ex cessive odors do not
necessarily indicate ex cessive emissions.)
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check”
performed?—Go to Step 2Go to OBD
System Check
2 1. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?—Verify repair Go to Step 3
3 Was a visual/physical check performed?
—Go to Step 4Go to Visual /
physical Check.
4 Does the customer continual accelerate On/Off during
cold condition?—System OK Go to Step 5
5 Is the customer using the incorrect fuel type?
—Replace with
unleaded fuel Go to Step 6
6 Check for vacuum leaks (vacuum lines, intake
manifold, throttle body, etc.)
Were any vacuum leaks found?—Go to Step 17Go to Step 7
7 1. Check fuel cap for proper installation.
2. Secure the fuel cap if necessary.
Was a problem found?—Go to Step 17Go to Step 8
8 Check the fuel pressure. Refer to 6E-108 page “Fuel
System Diagnosis” .
Was a problem found?—Go to Step 17Go to Step 9
9 1. Check for faulty, plugged or incorrectly installed
PCV valve.
2. Verify that the PCV system is not plugged.
Was a problem found? —Go to Step 17Go to Step 10
10 Check the injector connectors, if any of the injectors
are connected to an incorrect cylinder, correct as
necessary.
Was a problem found?—Go to Step 17Go to Step 11
11 Perform the
Injector Coil/Balance Test
(Refer to 6E-
98 page).
Was a problem found.—Go to Step 17Go to Step 12
12 Check for a problem with the engine cooling system.
Was a problem found?—Go to Step 17Go to Step 13
13 Check EVAP canister for fuel loading. Refer to
Evaporative Emission Control System.
Was a problem found?—Go to Step 17Go to Step 14
14 Check the EVAP purge solenoid valve operation.
Is the valve operated normally?—Go to Step 17Veri fy repai r &
Go to Step 15
15 Check the ex haust system for a possible restriction:
Damaged or collapsed pipes
Internal catalytic converter failure
Was a problem found?—Verify repair &
Go to Step 16Go to Step 17