6E–236 ENGINE DRIVEABILITY AND EMISSIONS
HARD START SYMPTOM
DEFINITIONS: Engine cranks, but does not start for a long time. Does eventually start, of may start and then
immediately stall.
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 visually/physical check performed?
—Go to Step 4Go to Visual /
physical Check.
4 1. Visually/physically inspect for the following
conditions:
Restriction of air intake system. Check for a
restricted air filter element, or foreign objects
blocking the air intake system
Check for objects blocking the IAC passage or
throttle bore, excessive deposits in the throttle
bore and on the throttle plate
Check for a condition that causes a large
vacuum leak, such as an incorrectly installed or
faulty crankcase ventilation hose/brake booster
hose.
Was a problem found?—Verify repair Go to Step 5
5 1. Using a Tech 2, display the IAC value.
2. Check for a faulty, plugged, or sticking IAC
operation.
Was the problem found?—Verify repair Go to Step 6
6 Check engine coolant temperature (ECT) sensor for
shift in value.
1. After 8 hours with hood up and the engine not
running, connect the Tech 2.
2. Ignition On, engine not running.
3. Using Tech 2, compare Engine Coolant
Temperature to Intake Air Temperature.
Are ECT and IAT within the specified value of each
other? 5°CGo to Step 8Go to Step 7
ENGINE DRIVEABILITY AND EMISSIONS 6E–239
ROUGH, UNSTABLE, OR INCORRECT IDLE, STALLING SYMPTOM
DEFINITIONS: Engine runs unevenly at idle. If severe,
the engine or vehicle may shake. Engine idle speed
may vary in RPM. Either condition may be severe
enough to stall the engine.
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 1. Check for faulty, plugged or incorrectly installed
PCV valve.
2. Verify that the PCV system is not plugged.
Was a problem found? —Verify repair Go to Step 5
5 1. Check for incorrect idle speed. Ensure that the
following conditions are present.
Engine fully warm
Accessories are “Off”
2. Using a Tech 2, monitor IAC position.
Is the IAC position within the specified values? 20-30 Steps Go to Step 7Go to Step 6
6 1. Visually/physically inspect for the following
conditions:
Restriction of the air intake system. Check for a
restricted air filter element, or foreign objects
blocking the air intake system.
Check for objects blocking the IAC passage or
throttle bore, excessive deposits in the throttle
bore and on the throttle plate.
Check for a condition that causes a large
vacuum leak, such as an incorrectly installed or
faulty crankcase ventilation hose/brake booster
hose.
Was a problem found?—Verify repair Go to Step 7
ENGINE DRIVEABILITY AND EMISSIONS 6E–249
10 Check items that can cause the engine to run rich.
Refer to DTC P1167 “Fuel Supply System Rich During
Deceleration Fuel Cut Off”.
Was a problem found?—Verify repair Go to Step 11
11 Monitor “B1S1 (Bank 1 Sensor 1) Status” on the Tech
2.
Is the “B1S1 (Bank 1 Sensor 1) Status” in the lean
condition?—Go to Step 12Go to Step 13
12 Check items that can cause the engine to run lean.
Refer to DTC P1171 “Fuel Supply System Lean
During Power Enrichment”.
Was a problem found?—Verify repair Go to Step 13
13 1. Visually/physically inspect for the following
conditions:
Restriction of air intake system. Check for a
restricted air filter element, or foreign objects
blocking the air intake system.
Check for objects blocking the IAC passage or
throttle bore, excessive deposits in the throttle
bore and on the throttle plate.
Check for a condition that causes a large
vacuum leak, such as an incorrectly installed or
faulty crankcase ventilation hose/brake booster
hose.
Was a problem found?—Verify repair Go to Step 14
14 Check the injector connectors, if any of the injectors
are connected an incorrect cylinder, correct as
necessary.
Was a problem found?—Verify repair Go to Step 15
15 Perform the “Injector Coil/Balance Test” (Refer to 6E-
98 page).
Was a problem found.—Verify repair Go to Step 16
16 1. Check for fuel in the pressure regulator vacuum
hose.
2. If fuel is present, replace the fuel pressure
regulator assembly.
Was a problem found?—Verify repair Go to Step 17
17 Check for proper ignition voltage output with the spark
tester.
Was a problem found?—Verify repair Go to Step 18
18 1. Remove the spark plugs and check for gas or oil
fouling cracks, wear, improper gap, burned
electrodes, heavy deposits, or improper heat
range.
2. If spark plugs are fouled, the cause of fouling must
be determined before replacing the spark plugs.
Was a problem found?—Verify repair Go to Step 19 Step Action Value(s) Yes No
6E–264 ENGINE DRIVEABILITY AND EMISSIONS
ON-VEHICLE SERVICE PROCEDURE
ENGINE CONTROL MODULE (ECM)
Location
On the intake manifold.
Removal Procedure
1. Disconnect the negative battery cable.
2. Disconnect the two connectors from the ECM.
3. Remove four bolts.
4. Remove the ECM from bracket.
Installation Procedure
1. Put on the ECM to the bracket.
2. Tighten the ECM by four bolts with specified
tightening torque.
Tightening torque
Bolts: 8.0 - 12.0 N·m (0.8 - 1.2 kgf·m)
3. Connect the two connectors to the ECM.
4. Connect the negative battery cable.
NOTE: Verify any DTCs (diagnosis Trouble Code) are
not stored after replacement.
CRANKSHAFT POSITION (CKP) SENSOR
Location
Left-hand side of the cylinder block. (Back of the A/C
compressor)
Removal Procedure
1. Disconnect the negative battery cable.
2. Remove the drive belt. Refer to Engine Mechanical
Section.
3. Remove the A/C compressor from engine. Refer to
Engine Mechanical Section.
4. Disconnect connector from the CKP sensor.
5. Loosen a bolt and remove the CKP sensor from the
cylinder block.
NOTE: Use caution to avoid any hot oil that might drip
out.
Installation Procedure
1. Install the CKP sensor to the cylinder block.
2. Tighten CKP sensor by a bolt with specified
tightening torque.
Tightening Torque
Bolt: 6N·m (0.6kgf·m)
3. Reinstall the A/C compressor to the engine.
4. Reinstall the accessory drive belt.
5. Connect the negative battery cable.
NOTE: Verify any DTCs (diagnosis Trouble Code) are
not stored after replacement.
6E–268 ENGINE DRIVEABILITY AND EMISSIONS
KNOCK SENSOR
Location
Right-hand side of the cylinder block.
Removal Procedure
1. Disconnect the negative battery cable.
2. Disconnect the knock sensor connector.
3. Loosen a bolt and remove knock sensor from the
cylinder block.
Installation Procedure
1. Tighten the knock sensor by a bolt with specified
tightening torque.
Tightening Torque
Bolt: 20N·m (2.0kgf·m)
2. Connect a knock sensor connector to the knock
sensor.
3. Connect the negative battery cable.
NOTE: Verify any DTCs (diagnosis Trouble Code) are
not stored after replacement.
POWER STEERING PRESSURE (PSP)
SWITCH
Location
Installed on the power steering pump assembly.
Removal Procedure
1. Disconnect the negative battery cable.
2. Disconnect the power steering pressure switch
connector.
3. Loosen and remove the power steering pressure
switch from the power steering pump.
Installation Procedure
1. Install the power steering pressure switch to the
power steering pump.
2. Tighten the power steering pressure switch.
3. Connect a connector to the power steering pressure
switch.
4. Connect the negative battery cable.
NOTE: Verify any DTCs (diagnosis Trouble Code) are
not stored after replacement.
Verify no power steering fluid leaking from the sensor
threads after replacement.
ENGINE EXHAUST 6F-3
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 passenger 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 rear 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 (If applicable)
The three way catalytic converter is an emission control device
added to the exhaust system to reduce pollutants from the
exhaust gas stream.
CAUTION: The catalytic converter requires the use of
unleaded fuel only.
Periodic maintenance of the exhaust system is not 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 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
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.
6G-2 ENGINE LUBRICATION
General Description
Legend
1 Oil Strainer
2 Oil Pump
3 Relief Valve
4 Oil Filter
5 Safety Valve
6 Oil Gallery
7 Crankshaft Bearing
8 Crankshaft9 Connecting Rod Bearing
10 Connecting Rod
11 Piston
12 Oil Gallery; Cylinder Head
13 Camshaft
14 Camshaft Journal
15 HLV
16 Check relief valve
17 Oil Pan
A gear-type oil pump is directly driven by the crankshaft and
draws oil from the oil pan, via the suction pipe. If then passes
the pressured oil through a full-flow disposable oil filter, to the
main oil gallery in the cylinder Block. An oil pump pressure
relief valve and oil filter bypass valve are incorporated in the
system.
From the main oil gallery in the cylinder block, the cylinder
head and crankshaft main bearings are supplied with oil.
The camshaft bearings and hydraulic tappets are supplied
through the main feed galleries in the cylinder head. Vent
valves allow air to be expelled from the oil galleries in the
cylinder head. The balance shaft journals are directly fed from
the crankshaft main bearings. The connecting rod bearings are
fed via passages in the crankshaft. The oil returns to the oil
pan via passages in the cylinder block.