2001 INFINITI QX4 compression ratio

IAir intake system
(Oil filler cap, oil level gauge, etc.)
IFuel pressure
IEngine compression
IThrottle valve
IEvaporative emission system
2) On air conditioner equipped models, checks should be carried out while the air conditioner is ªOFFº.
3) On automatic transmission equipped models, when checking idle rpm, ignition timing and mixture ratio,
checks should be carried out while shift lever is in ªNº position.
4) When measuring ªCOº percentage, insert probe more than 40 cm (15.7 in) into tail pipe.
5) Turn off headlamps, heater blower, rear defogger.
6) Keep front wheels pointed straight ahead.
7) Make the check after the cooling fan has stopped.
BASIC SERVICE PROCEDURE
Idle Speed/Ignition Timing/Idle Mixture Ratio Adjustment (Cont'd)
EC-44

Monitored item [Unit]ECM
input
signalsMain
signalsDescription Remarks
A/F ALPHA-B1 [%]q
IIndicates the mean value of the air-fuel ratio
feedback correction factor per cycle.IWhen the engine is running, specifi-
cation range is indicated.
IThis data also includes the data for
the air-fuel ratio learning control. A/F ALPHA-B2 [%]q
NOTE:
IAny monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
IRegarding R50 model, ªB1º indicates bank 1 and ªB2º indicates bank 2.
ACTIVE TEST MODENBEC0034S07
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
FUEL INJECTIONIEngine: Return to the original
trouble condition
IChange the amount of fuel injec-
tion using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.IHarness and connector
IFuel injectors
IHeated oxygen sensor
IGNITION TIMINGIEngine: Return to the original
trouble condition
ITiming light: Set
IRetard the ignition timing using
CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.IAdjust initial ignition timing
IACV-AAC/V
OPENINGIEngine: After warming up, idle
the engine.
IChange the IACV-AAC valve
opening percent using CON-
SULT-II.Engine speed changes according
to the opening percent.IHarness and connector
IIACV-AAC valve
POWER BAL-
ANCEIEngine: After warming up, idle
the engine.
IA/C switch ªOFFº
IShift lever ªNº
ICut off each injector signal one
at a time using CONSULT-II.Engine runs rough or dies.IHarness and connector
ICompression
IInjectors
IPower transistor
ISpark plugs
IIgnition coils
ENG COOLANT
TEMPIEngine: Return to the original
trouble condition
IChange the engine coolant tem-
perature using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.IHarness and connector
IEngine coolant temperature sen-
sor
IFuel injectors
FUEL PUMP
RELAYIIgnition switch: ON
(Engine stopped)
ITurn the fuel pump relay ªONº
and ªOFFº using CONSULT-II
and listen to operating sound.Fuel pump relay makes the operat-
ing sound.IHarness and connector
IFuel pump relay
VIAS SOL VALVEIIgnition switch: ON
ITurn solenoid valve ªONº and
ªOFFº with CONSULT-II and lis-
ten for operating sound.Solenoid valve makes an operating
sound.IHarness and connector
ISolenoid valve
SWIRL CONT
S O L VA LV EIIgnition switch: ON
ITurn solenoid valve ªONº and
ªOFFº with CONSULT-II and lis-
ten for operating sound.Solenoid valve makes an operating
sound.IHarness and connector
ISolenoid valve
PURG VOL
CONT/VIEngine: After warming up, run
engine at 1,500 rpm.
IChange the EVAP canister purge
volume control solenoid valve
opening percent using CON-
SULT-II.Engine speed changes according
to the opening percent.IHarness and connector
ISolenoid valve
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
CONSULT-II (Cont'd)
EC-91

Fail-safe Chart=NBEC0040The ECM enters fail-safe mode, if any of the following malfunctions is detected due to the open or short cir-
cuit. When the ECM enters the fail-safe mode, the MIL illuminates.
DTC No. Detected items Engine operating condition in fail-safe mode
P0100 Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.
P0115 Engine coolant temperature
sensor circuitEngine coolant temperature will be determined by ECM based on the time after
turning ignition switch ªONº or ªSTARTº.
CONSULT-II displays the engine coolant temperature decided by ECM.
ConditionEngine coolant temperature decided
(CONSULT-II display)
Just as ignition switch is turned
ON or Start40ÉC (104ÉF)
More than approx. 4 minutes
after ignition ON or Start80ÉC (176ÉF)
Except as shown above40 - 80ÉC (104 - 176ÉF)
(Depends on the time)
P0120 Throttle position sensor cir-
cuitThrottle position will be determined based on the injected fuel amount and the
engine speed.
Therefore, acceleration will be poor.
Condition Driving condition
When engine is idling Normal
When accelerating Poor acceleration
P1335 Crankshaft position sensor
(REF) circuitCompression TDC signal (120É signal) is controlled by camshaft position sensor
(PHASE) signal and crankshaft position sensor (POS) signal. Ignition timing will be
delayed 0É to 2É.
Unable to
access ECMECMECM fail-safe activating condition
The computing function of the ECM was judged to be malfunctioning.
When the fail-safe system activates (i.e., if the ECM detects a malfunction condi-
tion in the CPU of ECM), the MIL on the instrument panel lights to warn the driver.
However it is not possible to access ECM and DTC cannot be confirmed.
Engine control with fail-safe
When ECM fail-safe is operating, fuel injection, ignition timing, fuel pump operation,
IACV-AAC valve operation and cooling fan operation are controlled under certain
limitations.
ECM fail-safe operation
Engine speedEngine speed will not rise more than 3,000
rpm
Fuel injection Simultaneous multiport fuel injection system
Ignition timing Ignition timing is fixed at the preset valve
Fuel pumpFuel pump relay is ªONº when engine is running
and ªOFFº when engine stalls
IACV-AAC valve Full open
Replace ECM, if ECM fail-safe condition is confirmed.
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TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Fail-safe Chart
EC-117

On Board Diagnosis LogicNBEC0182When a misfire occurs, engine speed will fluctuate. If the engine
speed fluctuates enough to cause the CKP sensor signal to vary,
ECM can determine that a misfire is occurring.
Sensor Input Signal to ECM ECM function
Crankshaft position sensor (POS) Engine speed On board diagnosis of misfire
The misfire detection logic consists of the following two conditions.
1. One Trip Detection Logic (Three Way Catalyst Damage)
On the first trip that a misfire condition occurs that can dam-
age the three way catalyst (TWC) due to overheating, the MIL
will blink.
When a misfire condition occurs, the ECM monitors the CKP
sensor signal every 200 engine revolutions for a change.
When the misfire condition decreases to a level that will not
damage the TWC, the MIL will turn off.
If another misfire condition occurs that can damage the TWC
on a second trip, the MIL will blink.
When the misfire condition decreases to a level that will not
damage the TWC, the MIL will remain on.
If another misfire condition occurs that can damage the TWC,
the MIL will begin to blink again.
2. Two Trip Detection Logic (Exhaust quality deterioration)
For misfire conditions that will not damage the TWC (but will
affect vehicle emissions), the MIL will only light when the mis-
fire is detected on a second trip. During this condition, the ECM
monitors the CKP sensor signal every 1,000 engine revolu-
tions.
A misfire malfunction can be detected on any one cylinder or
on multiple cylinders.
Malfunction is detected when multiple cylinders misfire, No. 1 cyl-
inder misfires, No. 2 cylinder misfires, No. 3 cylinder misfires, No.
4 cylinder misfires, No. 5 cylinder misfires and No. 6 cylinder
misfires.
Possible CauseNBEC0490IImproper spark plug
IInsufficient compression
IIncorrect fuel pressure
IThe injector circuit is open or shorted
IInjectors
IIntake air leak
IThe ignition secondary circuit is open or shorted
ILack of fuel
IDrive plate or flywheel
IHeated oxygen sensor 1 (front)
DTC P0300 - P0306 NO.6-1CYLINDER MISFIRE, MULTIPLE CYLINDER
MISFIRE
On Board Diagnosis Logic
EC-320

ENGINE MECHANICAL
SECTION
EM
CONTENTS
PRECAUTIONS...............................................................3
Parts Requiring Angular Tightening .............................3
Liquid Gasket Application Procedure ..........................3
PREPARATION...............................................................4
Special Service Tools ..................................................4
Commercial Service Tools ...........................................6
NOISE, VIBRATION AND HARSHNESS (NVH)
TROUBLESHOOTING.....................................................8
NVH Troubleshooting - Engine Noise .........................9
OUTER COMPONENT PARTS.....................................10
Removal and Installation ...........................................10
TIGHTENING PROCEDURES...................................12
MEASUREMENT OF COMPRESSION PRESSURE....14
OIL PAN.........................................................................15
Components...............................................................15
Removal .....................................................................15
Installation ..................................................................18
TIMING CHAIN..............................................................20
Components...............................................................20
POSITION FOR APPLYING LIQUID GASKET............21
Removal .....................................................................23
Inspection...................................................................29
Installation ..................................................................29
OIL SEAL.......................................................................35
Replacement ..............................................................35
VALVE OIL SEAL.....................................................35
OIL SEAL INSTALLATION DIRECTION.....................36
FRONT OIL SEAL....................................................36
REAR OIL SEAL......................................................36
CYLINDER HEAD..........................................................38
Components...............................................................38
Removal .....................................................................39
Disassembly...............................................................41
Inspection...................................................................42
CYLINDER HEAD DISTORTION...............................42
CAMSHAFT VISUAL CHECK....................................42
CAMSHAFT RUNOUT..............................................42
CAMSHAFT CAM HEIGHT.......................................42
CAMSHAFT JOURNAL CLEARANCE........................42
CAMSHAFT END PLAY............................................43
CAMSHAFT SPROCKET RUNOUT...........................43
VALVE GUIDE CLEARANCE....................................43
VALVE GUIDE REPLACEMENT................................44
VALVE SEATS.........................................................45
REPLACING VALVE SEAT FOR SERVICE PARTS....45
VALVE DIMENSIONS...............................................46
VALVE SPRING.......................................................46
VALVE LIFTER........................................................46
Assembly ...................................................................47
Installation ..................................................................47
Valve Clearance.........................................................52
CHECKING.............................................................52
ADJUSTING............................................................54
ENGINE ASSEMBLY.....................................................57
Removal and Installation ...........................................57
REMOVAL...............................................................58
INSTALLATION........................................................60
CYLINDER BLOCK.......................................................61
Components...............................................................61
CYLINDER BLOCK HEATER....................................62
Removal and Installation ...........................................62
Disassembly...............................................................62
PISTON, CRANKSHAFT AND OIL JET......................62
Inspection...................................................................63
PISTON AND PISTON PIN CLEARANCE..................63
PISTON RING SIDE CLEARANCE............................64
PISTON RING END GAP..........................................64
CONNECTING ROD BEND AND TORSION...............65
CYLINDER BLOCK DISTORTION AND WEAR...........65
PISTON-TO-BORE CLEARANCE..............................66
CRANKSHAFT.........................................................67
BEARING CLEARANCE...........................................67
CONNECTING ROD BUSHING CLEARANCE
(SMALL END)
..........................................................70
DRIVE PLATE RUNOUT..........................................70
Assembly ...................................................................71
PISTON..................................................................71
OIL JET..................................................................71
CRANKSHAFT.........................................................71
REPLACEMENT OF PILOT CONVERTER.................74
DRIVE PLATE.........................................................74
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General SpecificationsNBEM0029
Cylinder arrangementV- 6
Displacement cm
3(cu in)3,498 (213.45)
Bore and stroke mm (in)95.5 x 81.4 (3.760 x 3.205)
Valve arrangementDOHC
Firing order1-2-3-4-5-6
Number of piston ringsCompression 2
Oil 1
Number of main bearings4
Compression ratio10.0
Compression PressureNBEM0030Unit: kPa (kg/cm2, psi)/300 rpm
Compression pressureStandard 1,275 (13.0, 185)
Minimum 981 (10.0, 142)
Differential limit between cylinders 98 (1.0, 14)
Cylinder number
SEM713A
Cylinder HeadNBEM0031Unit: mm (in)
Standard Limit
Head surface distortion Less than 0.03 (0.0012) 0.1 (0.004)
SEM949E
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SERVICE DATA AND SPECIFICATIONS (SDS)
General Specifications
EM-75

Brake fluid change ...........................................BR-7
Brake fluid level .............................................MA-25
Brake fluid level and line check .......................BR-7
Brake hydraulic line ..........................................BR-9
Brake inspection ............................................MA-25
Brake lines and cables inspection .................MA-25
Brake lining wear temporary checking ..........MA-26
Brake master cylinder ....................................BR-16
Brake pedal ....................................................BR-14
Bulb specifications ........................................EL-456
Bumper, front ..................................................BT-12
Bumper, rear ...................................................BT-15
BYPS/V - Wiring diagram ....................EC-587, 594
C
Camshaft inspection ......................................EM-42
Camshaft position sensor (PHASE) .............EC-342
Canister-See EVAP canister ..........................EC-32
Center bearing assembly (propeller
shaft) .............................................................PD-9
Center bearing disassembly (propeller
shaft) .............................................................PD-7
Center case (Transfer) ..................................TF-123
CHARGE - Wiring diagram ............................SC-20
Charging system ............................................SC-19
Chassis and body maintenance ....................MA-21
CHIME - Wiring diagram...............................EL-127
CIGAR - Wiring diagram ...............................EL-148
Cigarette lighter.............................................EL-148
Circuit breaker.................................................EL-16
CKPS - Wiring diagram ................................EC-334
Closed loop control (Left bank) ....................EC-491
Closed loop control (Right bank) .................EC-491
Closed throttle position switch .....................EC-431
Clutch drum (Transfer) ..................................TF-125
Clutch force release limit adjustment .............TF-39
Clutch pressure switch (Transfer) .................TF-111
Coil spring (front)..............................................SU-8
Coil spring (rear) ............................................SU-18
Collision diagnosis..........................................RS-59
Combination lamp, front, removal and
installation ...................................................BT-12
Combination lamp, rear, removal and
installation ...................................................BT-35
Combination meter..........................................EL-94
Combination meter removal and instal-
lation - See Instrument panel ......................BT-21
Combination switch .........................................EL-28
COMPAS - Wiring diagram ...........................EL-111
Compass .......................................................EL-110
Component Location (auto A/C).....................HA-27
Compression pressure ...................................EM-14
Compressor clutch removal and
installation .................................................HA-150
Compressor precaution ....................................HA-6
Compressor special service tool ....................HA-10
Connecting rod...............................................EM-65
Connecting rod bearing clearance.................EM-69
Connecting rod bushing clearance ................EM-70Connector inspection .......................................GI-21
Console box - See Instrument panel ..............BT-21
CONSULT for ABS .........................................BR-43
CONSULT for all-mode 4WD ..........................TF-30
CONSULT for engine .....................................EC-81
CONSULT-II general information .....................GI-38
Control valve (A/T) ........................................AT-301
Control valve (Transfer) ................................TF-128
Converter housing installation .......................AT-278
Coolant mixture ratio......................................MA-12
Coolant replacement ......................................MA-14
Cooling circuit (engine) ...................................LC-10
``Crankcase emission control system -
See positive crankcase ventilation''............EC-38
Crankshaft ......................................................EM-67
Crankshaft position sensor (POS) ...............EC-334
Crankshaft position sensor (POS)
chipping ....................................................EC-517
Crankshaft position sensor (REF) ................EC-510
Cruise control - See ASCD ...........................EL-221
Cylinder block ................................................EM-61
Cylinder head .................................................EM-38
Cylinder head bolt tightening .........................EM-49
D
Data link connector for Consult......................EC-81
Daytime light system.......................................EL-46
Daytime running light - See Daytime
light system .................................................EL-46
DEF - Wiring diagram ...................................EL-153
Detonation sensor - See Knock sensor .......EC-328
Diagnostic trouble code (DTC) for OBD
system ....................................................EC-8, 60
Diagnostic trouble code (DTC) inspec-
tion priority chart .......................................EC-116
Differential carrier assembly.....................PD-30, 57
Differential carrier disassembly ......................PD-44
Differential gear oil replacement ....................MA-24
Dimensions ......................................................GI-43
D/LOCK - Wiring diagram .............................EL-256
Dome light - See Interior lamp .......................EL-88
Door glass .......................................................BT-18
Door lock .........................................................BT-18
Door mirror ......................................................BT-56
Door trim .........................................................BT-30
Door, front .......................................................BT-18
Door, rear ........................................................BT-20
Drive belt inspection ......................................MA-13
Drive chain (Transfer) ...................................TF-125
Drive pinion diff. inspection ......................PD-23, 47
Drive pinion height ...................................PD-25, 53
Drive plate runout ..........................................EM-70
Drive shaft (front)............................................AX-10
Dropping resistor (A/T) ..................................AT-167
DTC work support ..........................................EC-93
DTRL - Wiring diagram ...................................EL-51
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ALPHABETICAL INDEX
IDX-3