2001 INFINITI QX4 fuel pressure

Fuel Pressure RegulatorNBEC0408
Fuel pressure at idling kPa (kg/cm2, psi)
Vacuum hose is connected. Approximately 235 (2.4, 34)
Vacuum hose is disconnected. Approximately 294 (3.0, 43)
Idle Speed and Ignition TimingNBEC0409
Target idle speed*1 No-load*2 (in ªPº or Nº position) 750±50 rpm
Air conditioner: ON In ªPº or Nº position 825 rpm or more
Ignition timing*1 In ªPº or Nº position 15ɱ5É BTDC
Throttle position sensor idle position0.15 - 0.85V
*1: Throttle position sensor harness connector connected
*2: Under the following conditions:
IAir conditioner switch: OFF
IElectric load: OFF (Lights, heater fan & rear window defogger)
ISteering wheel: Kept in straight-ahead position
Mass Air Flow SensorNBEC0411
Supply voltageBattery voltage (11 - 14)V
Output voltage at idle1.2 - 1.8*V
Mass air flow (Using CONSULT-II or GST)2.0 - 6.0 g´m/sec at idle*
7.0 - 20.0 g´m/sec at 2,500 rpm*
*: Engine is warmed up to normal operating temperature and running under no-load.
Engine Coolant Temperature SensorNBEC0412
Temperature ÉC (ÉF) Resistance kW
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
Heated Oxygen Sensor 1 Heater (Front)NBEC0414
Resistance [at 25ÉC (77ÉF)]2.3 - 4.3W
Fuel PumpNBEC0415
Resistance [at 25ÉC (77ÉF)]0.2 - 5.0W
IACV-AAC ValveNBEC0416
Resistance [at 20ÉC (68ÉF)]Approximately 20 - 24W
InjectorNBEC0417
Resistance [at 20ÉC (68ÉF)]13.5 - 17.5W
ResistorNBEC0418
Resistance [at 25ÉC (77ÉF)]Approximately 2.2 kW
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
SERVICE DATA AND SPECIFICATIONS (SDS)
Fuel Pressure Regulator
EC-649

SEL350X
Aiming AdjustmentNBEL0029Before performing aiming adjustment, make sure of the following.
1) Keep all tires inflated to correct pressure.
2) Place vehicle on level ground.
3) See that vehicle is unloaded (except for full levels of coolant,
engine oil and fuel, and spare tire, jack, and tools). Have the
driver or equivalent weight placed in driver's seat.
Adjust aiming in the vertical direction by turning the adjusting
screw.
MEL327G
1. Set the distance between the screen and the center of the fog
lamp lens as shown at left.
2. Turn front fog lamps ON.
MEL328GA
3. Adjust front fog lamps so that the top edge of the high inten-
sity zone is 200 mm (7.9 in) below the height of the fog lamp
centers as shown at left.
IWhen performing adjustment, if necessary, cover the head-
lamps and opposite fog lamp.
FRONT FOG LAMP
Aiming Adjustment
EL-74

SEL062WA
Fuel Warning Lamp Sensor CheckNBEL01661. Turn ignition switch ªOFFº.
2. Disconnect fuel level sensor unit harness connector B12.
3. Connect a resistor (80W) between fuel tank gauge unit harness
connector terminals 2 and 3.
4. Turn ignition switch ªONº.
The fuel warning lamp should come on.
NOTE:
ECM might store the 1st trip DTC P0180 during this inspection.
If the DTC is stored in ECM memory, erase the DTC after recon-
necting fuel tank gauge unit harness connector.
Refer to EC-60, ªHOW TO ERASE EMISSION-RELATED DIAG-
NOSTIC INFORMATIONº.
MEL425F
Electrical Components InspectionNBEL0051OIL PRESSURE SWITCH CHECKNBEL0051S02
Oil pressure
kPa (kg/cm2, psi)Continuity
Engine startMore than 10 - 20
(0.1-0.2,1-3)NO
Engine stopLess than 10 - 20
(0.1-0.2,1-3)YES
Check the continuity between the terminals of oil pressure switch
and body ground.
SEL901F
DIODE CHECKNBEL0051S03ICheck continuity using an ohmmeter.
IDiode is functioning properly if test results are as shown in the
figure at left.
ICheck diodes at the combination meter harness connector
instead of checking them on the combination meter assembly.
Refer to EL-115, ªWARNING LAMPº wiring diagrams.
NOTE:
Specification may vary depending on the type of tester. Before
performing this inspection, be sure to refer to the instruction
manual for the tester to be used.
WARNING LAMPS
Fuel Warning Lamp Sensor Check
EL-122

NBEL0145
Use the chart below to find out what each wiring
diagram code stands for.
Refer to the wiring diagram code in the alphabetical
index to find the location (page number) of each
wiring diagram.
Code Section Wiring Diagram Name
1STSIG AT A/T 1ST Signal
2NDSIG AT A/T 2ND Signal
3RDSIG AT A/T 3RD Signal
4THSIG AT A/T 4TH Signal
A/C, A HA Auto Air Conditioner
AAC/V EC IACV-AAC Valve
ABS BR Anti-lock Brake System
AP/SEN EC Absolute Pressure Sensor
ASCD EL Automatic Speed Control Device
AT/C EC A/T Control
ATDIAG EC A/T Diagnosis Communication
Line
AT/IND EL A/T Indicator Lamp
AUDIO EL Audio
AUT/DP EL Automatic Drive Positioner
BA/FTS AT A/T Fluid Temperature Sensor
and TCM Power Supply
BACK/L EL Back-up Lamp
BYPS/V EC Vacuum Cut Valve Bypass Valve
CHARGE SC Charging System
CHIME EL Warning Chime
CIGAR EL Cigarette Lighter
CLOCK EL Clock
COMPAS EL Compass and Thermometer
D/LOCK EL Power Door Lock
DEF EL Rear Window Defogger
DTRL EL Headlamp Ð With Daytime Light
System Ð
ECTS EC Engine Coolant Temperature Sen-
sor
ENGSS AT Engine Speed Signal
F/FOG EL Front Fog Lamp
F/LID EL Fuel Lid Opener
F/PUMP EC Fuel Pump Control
FICD EC IACV-FICD Solenoid Valve
FLS1 EC Fuel Gauge
Code Section Wiring Diagram Name
FLS2 EC Fuel Gauge
FLS3 EC Fuel Gauge
FTS AT A/T Fluid Temperature Sensor
FUELLH EC Fuel Injection System Function
(Left Bank)
FUELRH EC Fuel Injection System Function
(Right Bank)
H/AIM EL Headlamp Aiming Control System
H/LAMP EL Headlamp
HORN EL Horn
HSEAT EL Heated Seat
IATS EC Intake Air Temperature Sensor
IGN/SG EC Ignition Signal
ILL EL Illumination
INJECT EC Injector
INT/L EL Interior, Spot, Vanity Mirror, and
Luggage Room Lamps
IVC-L EC Intake Valve Timing Control Sole-
noid Valve LH
IVC-R EC Intake Valve Timing Control Sole-
noid Valve RH
IVCS EL INFINITI Communicator
IVCS-L EC Intake Valve Timing Control Posi-
tion Sensor LH
IVCS-R EC Intake Valve Timing Control Posi-
tion Sensor RH
KS EC Knock Sensor
LAN AT A/T Communication Line
LOAD EC Electrical Load Signal
LPSV AT Line Pressure Solenoid Valve
MAFS EC Mass Air Flow Sensor
MAIN AT Main Power Supply and Ground
Circuit
MAIN EC Main Power Supply and Ground
Circuit
METER EL Speedometer, Tachometer, Temp.,
Oil, and Fuel Gauges
MIL/DL EC MIL and Data Link Connectors
MIRROR EL Door Mirror
MULTI EL Multi-remote Control System
NATS EL IVIS (Infiniti Vehicle Immobiliser
System)
GI
MA
EM
LC
EC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
IDX
WIRING DIAGRAM CODES (CELL CODES)
EL-457

Code Section Wiring Diagram Name
NAVI EL Navigation System
NONDTC AT Non-detectable Items
O2H1B1 EC Heated Oxygen Sensor 1 Heater
(Front) (Bank 1)
O2H1B2 EC Heated Oxygen Sensor 1 Heater
(Front) (Bank 2)
O2H2B1 EC Heated Oxygen Sensor 2 Heater
(Rear) (Bank 1)
O2H2B2 EC Heated Oxygen Sensor 2 Heater
(Rear) (Bank 2)
O2S1B1 EC Heated Oxygen Sensor 1 (Front)
(Bank 1)
O2S1B2 EC Heated Oxygen Sensor 1 (Front)
(Bank 2)
O2S2B1 EC Heated Oxygen Sensor 2 (Rear)
(Bank 1)
O2S2B2 EC Heated Oxygen Sensor 2 (Rear)
(Bank 2)
OVRCSV AT Overrun Clutch Solenoid Valve
P/ANT EL Power Antenna
PGC/V EC EVAP Canister Purge Volume
Control Solenoid Valve
PHASE EC Camshaft Position Sensor
(PHASE)
PNP/SW EC Park/Neutral Position Switch
PNP/SW AT Park/Neutral Position Switch
POS EC Crankshaft Position Sensor
(CKPS) (POS)
POWER EL Power Supply Routing
PRE/SE EC EVAP Control System Pressure
Sensor
PST/SW EC Power Steering Oil Pressure
Switch
REF EC Crankshaft Position Sensor
(CKPS) (REF)
REMOTE EL Audio (Remote Control Switch)
RP/SEN EC Refrigerant Pressure
S/SIG EC Start Signal
S/VCSW EC Swirl Control Valve Control
Vacuum Check Switch
SEAT EL Power Seat
SHIFT AT A/T Shift Lock System
SROOF EL Sunroof
SRS RS Supplemental Restraint SystemCode Section Wiring Diagram Name
SSV/A AT Shift Solenoid Valve A
SSV/B AT Shift Solenoid Valve B
START SC Starting System
STOP/L EL Stop lamp
SWL/V EC Swirl Control Valve Control Sole-
noid Valve
TAIL/L EL Parking, License and Tail Lamps
TCCSIG AT A/T TCC Signal (Lock up)
TCV AT Torque Converter Clutch Solenoid
Valve
T/F TF Transfer
TFTS EC Tank Fuel Temperature Sensor
THEFT EL Theft Warning System
TLID EL Glass Hatch Opener
TP/SW EC Throttle Position Switch
TPS AT Throttle Position Sensor
TPS EC Throttle Position Sensor
TRNSMT EL Integrated HOMELINKYTrans-
mitter
TRSA/T AT Turbine Revolution Sensor
TURN EL Turn Signal and Hazard Warning
Lamps
VIAS/V EC Variable Induction Air Control Sys-
tem
VSS EC Vehicle Speed Sensor
VSSA/T AT Vehicle Speed Sensor A/T (Revo-
lution Sensor)
VSSMTR AT Vehicle Speed Sensor MTR
WARN EL Warning Lamps
WINDOW EL Power Window
WIP/R EL Rear Wiper and Washer
WIPER EL Front Wiper and Washer
WIRING DIAGRAM CODES (CELL CODES)
EL-458

Removal and InstallationNBEM0006
SEM483G
1. Intake manifold collector support
2. Lower intake manifold collector
3. Fuel damper and fuel feed hose
assembly
4. Injector
5. Fuel tube assembly6. Fuel pressure regulator
7. Ignition coil with power transistor
8. Upper intake manifold collector
9. Intake manifold
10. Throttle body11. IACV-AAC valve
12. EVAP canister purge volume con-
trol solenoid valve
13. Swirl control valve
14. Variable induction air control valve
control actuator
OUTER COMPONENT PARTS
Removal and Installation
EM-10

SEM950F
TIGHTENING PROCEDURESNBEM0006S01Intake ManifoldNBEM0006S0101ITighten in numerical order shown in the figure.
1. Tighten all bolts and nuts to 5 to 10 N´m (0.5 to 1.0 kg-m, 44
to 86 in-lb).
2. Finally tighten all bolts and nuts to 26 to 31 N´m (2.7 to 3.2
kg-m, 20 to 23 ft-lb).
ITighten all bolts and nuts to the final torque, evenly dividing the
tightening into at least five steps.
SEM473G
Fuel TubeNBEM0006S0102ITighten in numerical order shown in the figure.
1. Tighten all bolts to 9.3 to 10.8 N´m (0.95 to 1.1 kg-m, 83 to 95
in-lb).
2. Then tighten all bolts to 21 to 26 N´m (2.1 to 2.7 kg-m, 15 to
20 ft-lb).
SEM474G
Fuel Pressure RegulatorNBEM0006S0103Tighten fuel pressure regulator to 2.9 to 3.8 N´m (0.3 to 0.39 kg-m,
26.0 to 33.9 in-lb).
ITighten screws evenly several times to have the fuel pres-
sure regulator tightened at the specified torque.
IAlways replace O-ring with new ones.
ILubricate O-ring with new engine oil.
SEM475G
Throttle BodyNBEM0006S0105ITighten in numerical order shown in the figure.
1. Tighten all bolts to 8.8 to 10.8 N´m (0.9 to 1.1 kg-m, 79 to 95
in-lb).
2. Then tighten all bolts to 18 to 21 N´m (1.8 to 2.2 kg-m, 13 to
15 ft-lb).
SEM476G
Upper Intake Manifold CollectorNBEM0006S0107Tighten bolts and nuts to 18 to 21 N´m (1.8 to 2.2 kg-m, 13 to 15
ft-lb) in numerical order shown in the figure.
OUTER COMPONENT PARTS
Removal and Installation (Cont'd)
EM-12

NBEM0007
SEM480G
SEM481G
JEM482G
SEM387C
1. Warm up engine.
2. Turn ignition switch OFF.
3. Release fuel pressure.
Refer to EC-39, ªFuel Pressure Releaseº.
4. Remove engine cover and throttle wire.
5. Remove air duct with air cleaner case.
6. Remove harness connectors and harness brackets around
ignition coils.
7. Remove throttle body.
8. Disconnect ignition coil with power transistor harness
connectors, then remove ignition coils.
9. Remove all spark plugs.
IClean area around plug with compressed air before removing
the spark plug.
10. Attach a compression tester to No. 1 cylinder.
11. Depress accelerator pedal fully to keep throttle valve wide
open.
12. Crank engine and record highest gauge indication.
13. Repeat the measurement on each cylinder as shown above.
IAlways use a fully-charged battery to obtain specified
engine speed.
Unit: kPa (kg/cm2, psi)/rpm
Standard MinimumDifference limit between
cylinders
1,275 (13.0, 185)/300 981 (10.0, 142)/300 98 (1.0, 14)/300
14. If compression in one or more cylinders is low:
a. Pour a small amount of engine oil into cylinders through spark
plug holes.
b. Retest compression.
IIf adding oil helps compression, piston rings may be worn
or damaged. If so, replace piston rings after checking pis-
ton.
IIf pressure stays low, a valve may be sticking or seating
improperly. Inspect and repair valve and valve seat. (Refer
to SDS, EM-76 and EM-79.) If valve or valve seat is dam-
aged excessively, replace them.
IIf compression stays low in two cylinders that are next to
each other:
a) The cylinder head gasket may be leaking, or
b) Both cylinders may have valve component damage. Inspect
and repair as necessary.
15. Install parts in reverse order of removal.
16. Perform ªSelf-diagnosis Procedureº referring to EC-72, ªHow to
Erase DTCº if any DTC appears.
MEASUREMENT OF COMPRESSION PRESSURE
EM-14