2004 INFINITI QX56 fuel pump

EC-650Revision: August 2007
SERVICE DATA AND SPECIFICATIONS (SDS)
2004 QX56
InjectorUBS00HEK
Fuel PumpUBS00HEL
Resistance [at 10 - 60°C (50 - 140°F)] 11.1 - 14.5Ω
Resistance [at 25°C (77°F)] 0.2 - 5.0Ω

CYLINDER HEAD
EM-59
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Revision: August 20072004 QX56
CYLINDER HEADPFP:11041
On-Vehicle ServiceEBS00ILS
CHECKING COMPRESSION PRESSURE
1. Warm up engine thoroughly. Then stop engine.
2. Release fuel pressure. Refer to EC-46, "
FUEL PRESSURE RELEASE" .
a. Remove fuel pump fuse, and start engine.
Refer to PG-78, "
FUSE AND RELAY BOX" or fuel pump fuse location.

Let fuel pump fuse removed until the end of step 7.
b. After engine stalls, crank it two or three times to release all fuel pressure.
3. Remove ignition coil and spark plug from each cylinder.
Refer to EM-27, "
REMOVAL" .
4. Connect engine tachometer (not required in use of CONSULT-II).
5. Install compression tester with Tool into spark plug hole.
6. With accelerator pedal fully depressed, turn ignition switch to “START” for cranking. When the gauge
pointer stabilizes, read the compression pressure and engine rpm. Perform these steps to check each cyl-
inder.
Unit: kPa (kg/cm2 , psi) /rpm
CAUTION:
Always use a fully charged battery to obtain specified engine speed.

If the engine speed is out of specified range, check battery liquid for proper gravity. Check engine
speed again with normal battery gravity.

If compression pressure is below minimum value, check valve clearances and parts associated with
combustion chamber (valve, valve seat, piston, piston ring, cylinder bore, cylinder head, cylinder head
gasket). After the checking, measure compression pressure again.

If some cylinders have low compression pressure, pour small amount of engine oil into the spark plug
hole of the cylinder to re-check it for compression.
–If the added engine oil improves the compression, the piston rings may be worn out or damaged. Check
the piston rings and replace if necessary.
–If the compression pressure remains at low level despite the addition of engine oil, the valves may be
malfunctioning. Check the valves for damage. Replace the valve or valve seat accordingly.

If two adjacent cylinders have respectively low compression pressure and their compression remains
low even after the addition of engine oil, the gaskets may be leaking, or valve in adjacent cylinders may
be damaged. Inspect and repair as required.
7. After inspection is complete, install removed parts. Installation is in the reverse order of removal.
8. Start engine, and confirm that engine runs smoothly.
9. Perform trouble diagnosis. If DTC appears, erase it. Refer to EC-71, "
TROUBLE DIAGNOSIS" . Tool number : EG15050500 (J-45402)
WBIA0605E
Standard MinimumDeference limit
between cylinders
1,520 (15.5, 220) / 200 1,324 (13.5, 192) / 200 98 (1.0, 14) / 300

EM-60Revision: August 2007
CYLINDER HEAD
2004 QX56
Removal and InstallationEBS00ILT
REMOVAL
1. Remove engine assembly from vehicle. Refer to EM-70, "REMOVAL" .
2. Remove the following components and related parts:

Auto tensioner of drive belts and idler pulley. Refer to EM-12, "DRIVE BELTS" .

Thermostat housing and hose. Refer to CO-17, "Removal of Thermostat Housing, Water Outlet and
Heater Pipe" .

Oil pan and oil strainer. Refer to EM-22, "OIL PAN AND OIL STRAINER" .

Fuel tube and fuel injector assembly. Refer to EM-29, "FUEL INJECTOR AND FUEL TUBE" .

Intake manifold. Refer to EM-15, "INTAKE MANIFOLD" .

Ignition coil. Refer to EM-26, "IGNITION COIL" .

Rocker cover. Refer to EM-33, "ROCKER COVER" .
3. Remove crankshaft pulley, front cover, oil pump, and timing chain. Refer to EM-35, "
TIMING CHAIN" .
4. Remove camshaft sprockets and camshafts. Refer to EM-43, "
CAMSHAFT" .
5. Remove cylinder head bolts in reverse order shown.
1. Harness bracket 2. Engine coolant temperature sensor 3. Washer
4. Cylinder head gasket (left bank) 5. Cylinder head (right bank) 6. Cylinder head bolt
7. Cylinder head gasket (right bank) 8. Cylinder head (left bank)
KBIA2528E
PBIC0068E

ENGINE ASSEMBLY
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Revision: August 20072004 QX56
5. Remove the cowl extension. Refer to EI-18, "Removal and Installation" .
6. Remove engine room cover using power tools.
7. Remove the air duct and air cleaner case assembly. Refer to EM-14, "
REMOVAL" .
8. Disconnect vacuum hose between vehicle and engine and set it aside.
9. Remove the radiator assembly and hoses. Refer to CO-10, "
REMOVAL" .
10. Remove the drive belts. Refer to EM-12, "
Removal" .
11. Remove the fan blade. Refer to CO-13, "
REMOVAL" .
12. Disconnect the engine room harness from the fuse box and set it aside for easier work.
13. Disconnect the ECM.
14. Disconnect the engine room harness from the engine side and set it aside for easier work.
15. Disconnect the engine harness grounds.
16. Disconnect the reservoir tank for power steering from engine and move it aside for easier work.
17. Disconnect power steering oil pump from engine. Move it from its location and secure with a rope for eas-
ier work. Refer to PS-26, "
REMOVAL" .
18. Remove the A/C compressor bolts and set aside. Refer to ATC-166, "
REMOVAL" .
19. Disconnect brake booster vacuum line.
20. Disconnect EVAP line.
21. Disconnect the fuel hose at the engine side connection. Refer to EM-29, "
REMOVAL" .
22. Disconnect the heater hoses at cowl, and install plugs to avoid leakage of engine coolant.
23. Remove the A/T oil level indicator and indicator tube upper bolts.
24. Remove the A/T. Refer to AT-255, "
Removal and Installation (4x2)" , or AT-258, "Removal and Installation
(4x4)" .
25. Install engine slingers into left bank cylinder head and right bank
cylinder head.
26. Lift with hoist and secure the engine in position.
27. Remove engine assembly from vehicle, avoiding interference
with vehicle body.
CAUTION:

Before and during this lifting, always check if any har-
nesses are left connected.
28. Remove alternator. Refer to SC-27, "
REMOVAL" .
29. Remove engine mounting insulator and bracket using power tool.
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:

When replacing an engine or transmission you must make sure the dowels are installed correctly
during re-assembly.

Improper alignment caused by missing dowels may cause vibration, oil leaks or breakage of driv-
etrain components.
WBIA0464E
Engine slinger torque: 45.0 N·m (4.6 kg-m, 33 ft-lb)
PBIC1556E

FL-1
FUEL SYSTEM
B ENGINE
CONTENTS
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SECTION FL
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FL
Revision: August 20072004 QX56 PREPARATION ........................................................... 2
Special Service Tools ............................................... 2
Commercial Service Tool ......................................... 2
FUEL SYSTEM ........................................................... 3
Checking Fuel Lines ................................................. 3
General Precautions ................................................ 3
FUEL LEVEL SENSOR UNIT, FUEL FILTER AND
FUEL PUMP ASSEMBLY ........................................... 5
Removal and Installation .......................................... 5
REMOVAL ............................................................. 5
INSTALLATION ..................................................... 8
INSPECTION AFTER INSTALLATION ................. 8FUEL TANK ................................................................ 9
Removal and Installation .......................................... 9
REMOVAL ........................................................... 10
INSTALLATION ................................................... 13
INSPECTION AFTER INSTALLATION ................ 13
SERVICE DATA AND SPECIFICATIONS (SDS) ...... 14
Standard and Limit .................................................. 14

FUEL LEVEL SENSOR UNIT, FUEL FILTER AND FUEL PUMP ASSEMBLY
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Revision: August 20072004 QX56
FUEL LEVEL SENSOR UNIT, FUEL FILTER AND FUEL PUMP ASSEMBLYPFP:17042
Removal and InstallationEBS00IKP
REMOVAL
WA RN ING:
Follow the “General Precautions” before working on the fuel system. Refer to FL-3, "
General Precau-
tions" .
1. Remove the fuel filler cap to release the pressure from inside the fuel tank.
2. Check the fuel level on level gauge. If the fuel gauge indicates
more than the level as shown (full or almost full), drain the fuel
from the fuel tank until the fuel gauge indicates the level as
shown, or less.

If the fuel pump does not operate, use the following procedure
to drain the fuel to the specified level.
a. Insert a suitable hose of less than 15 mm (0.59 in) diameter into
the fuel filler pipe through the fuel filler opening to drain the fuel
from fuel filler pipe.
b. Remove the LH rear wheel and tire. Refer to WT-6, "
Rotation" .
c. Remove the four clips and remove the rear fender protector,
front.
1. Inspection hole cover 2. Inspection hole cover O-ring 3. Lock ring
4. Fuel level sensor, fuel filter, and fuel
pump assembly5. Fuel tank 6. Fuel level sensor, fuel filter, and fuel
pump assembly O-ring
LBIA0381E
WBIA0390E

FL-6Revision: August 2007
FUEL LEVEL SENSOR UNIT, FUEL FILTER AND FUEL PUMP ASSEMBLY
2004 QX56
d. Disconnect the fuel filler hose from the fuel filler pipe.
e. Insert a suitable hose into the fuel tank through the fuel filler hose to drain the fuel from the fuel tank.

As a guide, the fuel level reaches the fuel gauge position as shown, or less, when approximately 14
liters (3 3/4 US gal, 3 1/8 Imp gal) of fuel are drained from the fuel tank.
3. Release the fuel pressure from the fuel lines. Refer to EC-46, "
FUEL PRESSURE RELEASE" .
4. Remove the second row LH rear seat and the third row rear seat. Refer to SE-103, "
REAR SEAT" .
5. Remove the second and third row rear seat belt buckles mounted on the floor. Refer to SB-3, "
SEAT
BELTS" .
6. Remove the LH center pillar trim, the LH rear trim panel, and the LH rear side door kick plate and weather
stripping. Refer to EI-34, "
BODY SIDE TRIM" .
7. Remove the second row rear center console and base, if equipped. Refer to EI-36, "
FLOOR TRIM" .
8. Reposition the floor carpet out of the way to access the inspection hole cover, located under the center LH
rear seat.
9. Remove the inspection hole cover by turning the retainers 90°
degrees clockwise.

Remove the O-ring.
10. Disconnect the fuel level sensor, fuel filter, and fuel pump
assembly electrical connector, the EVAP hose, and the fuel feed
hose.
LBIA0386E
LBIA0382E
LBIA0383E

FUEL LEVEL SENSOR UNIT, FUEL FILTER AND FUEL PUMP ASSEMBLY
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Revision: August 20072004 QX56
Disconnect the quick connector as follows:

Hold the sides of the connector, push in tabs and pull out the
tube.

If the connector and the tube are stuck together, push and pull
several times until they start to move. Then disconnect them
by pulling.
CAUTION:

The quick connector can be disconnected when the tabs
are completely depressed. Do not twist the quick connec-
tor more than necessary.

Do not use any tools to disconnect the quick connector.

Keep the resin tube away from heat. Be especially careful
when welding near the tube.

Prevent any acid liquids such as battery electrolyte, from
getting on the resin tube.

Do not bend or twist the resin tube during connection.

Do not remove the remaining retainer on the hard tube (or
the equivalent) except when the resin tube or the retainer
is replaced.

When the resin tube or hard tube, or the equivalent, is
replaced, also replace the retainer with a new one (white
colored retainer).

To keep the quick connector clean and to avoid damage
and contamination from foreign materials, cover the
quick connector with plastic bags or suitable material as
shown.
SF E5 62 A
PBIC1268E
PBIC0163E