2004 INFINITI QX56 fuel

EM-20Revision: August 2007
EXHAUST MANIFOLD AND THREE WAY CATALYST
2004 QX56
c. Remove the air fuel ratio A/F sensors from both left and right
exhaust manifolds using Tool.
CAUTION:

Be careful not to damage the air fuel ratio A/F sensors

Discard any air fuel ratio A/F sensor which has been
dropped from a height of more than 0.5m (19.7 in) onto a
hard surface such as a concrete floor. Replace it with a
new one.
7. Remove the front cross bar.
8. Remove the exhaust manifold (left bank) using the following
steps.
a. Remove the exhaust front tube using power tool. Refer to EX-3,
"Removal and Installation" .
b. Remove the exhaust manifold cover.
c. Loosen the nuts in reverse order shown using power tool.
d. Remove the exhaust studs from positions 2, 4, 6, 8 and remove
the left exhaust manifold.
9. Remove the exhaust manifold (right bank) using the following
steps.
a. Remove the exhaust front tube using power tool. Refer to EX-3,
"Removal and Installation" .
b. Remove the oil level gauge guide. Refer to EM-22, "
OIL PAN
AND OIL STRAINER" .
c. Remove the exhaust manifold cover.
d. Loosen the nuts in reverse order shown using power tool.
e. Remove the exhaust studs from positions 2, 4, 6, 8 and remove the right exhaust manifold.
INSPECTION AFTER REMOVAL
Surface Distortion

Use a reliable straightedge and feeler gauge to check the flat-
ness of each exhaust manifold flange surface.

If flatness exceeds the limit, replace the exhaust manifold.
INSTALLATION
Installation is in the reverse order of removal.

Install a new exhaust manifold gasket with the top of the triangu-
lar up mark on it facing up and its coated face (gray side) toward
the exhaust manifold side.Tool number : — (J-44626)
WBIA0630E
KBIA2464E
Flatness limit : 0.3 mm (0.012 in)
KBIA2504E
KBIA2553E

EXHAUST MANIFOLD AND THREE WAY CATALYST
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Revision: August 20072004 QX56

Tighten the exhaust manifold nuts in the numerical order shown.
Then recheck the torque of the nuts.

Before installing new air fuel ration A/F sensors, clean the exhaust system threads using Tool and apply
anti-seize lubricant.
CAUTION:

Do not over tighten the air fuel ratio A/F sensors. Doing so may cause damage to the sensor,
resulting in the MIL coming on.
KBIA2464E
Tool number : ( — ) J-43879-12
: ( — ) J-43897-18

FUEL INJECTOR AND FUEL TUBE
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Revision: August 20072004 QX56
FUEL INJECTOR AND FUEL TUBEPFP:16600
Removal and InstallationEBS00ILK
CAUTION:
Do not remove or disassemble parts unless instructed as shown.
REMOVAL
1. Remove the engine room cover using power tool. Refer to EM-11, "REMOVAL" .
2. Release the fuel pressure. Refer to EC-46, "
FUEL PRESSURE RELEASE" .
3. Disconnect the negative battery terminal.
4. Disconnect the fuel injector harness connectors.
5. Disconnect the fuel hose assembly from the fuel tubes (right bank and left bank).
CAUTION:

Plug the fuel hoses to prevent fuel from draining.

Do not separate the fuel connector and fuel hose.
6. Remove the fuel injectors with the fuel tube assembly.
1. Fuel tube (right bank) 2. Cap 3. Fuel damper
4. O-ring 5. O-ring (Blue) 6. Fuel injector
7. Clip 8. O-ring (Brown) 9. O-ring
10. Fuel hose assembly 11. Fuel tube (left bank)
KBIA2472E

EM-30Revision: August 2007
FUEL INJECTOR AND FUEL TUBE
2004 QX56
7. Remove the fuel injector from the fuel tube using the following
steps.
a. Spread open and remove the clip.
b. Remove the fuel injector from the fuel tube by pulling straight
out.
CAUTION:

Be careful with remaining fuel that may leak out from fuel
tube.

Do not damage injector nozzles during removal.

Do not bump or drop fuel injectors.

Do not disassemble fuel injectors.
8. Remove the fuel damper from each fuel tube.
INSTALLATION
1. Install the fuel damper to each fuel tube using the following
steps.
a. Apply engine oil to the new O-ring and set it into the cap of the
fuel tube.
CAUTION:

Handle O-ring with bare hands. Never wear gloves.

Lubricate new O-ring with new engine oil.

Do not clean O-ring with solvent.

Make sure that O-ring and its mating part are free of for-
eign material.

When installing O-ring, do not scratch it with tool or fin-
gernails.

Do not twist or stretch the O-ring.
b. Make sure that the backup spacer is in the O-ring connecting surface of the fuel damper.
NOTE:
The backup spacer is part of the fuel damper assembly.
c. Insert the fuel damper until it seats on the fuel tube.
CAUTION:

Insert straight, making sure that the axis is lined up.

Do not pressure-fit with excessive force.
d. Install the cap, and then tighten the bolts evenly.

After tightening the bolts, make sure that there is no gap between the cap and fuel tube.
2. Install new O-rings to the fuel injector paying attention to the items below.
CAUTION:

Upper and lower O-ring are different.
KBIA2506E
Reference value :130 N (13.3 kg, 29.2 lb)
KBIA2473E

FUEL INJECTOR AND FUEL TUBE
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Revision: August 20072004 QX56

Handle O-ring with bare hands. Never wear gloves.

Lubricate O-ring with new engine oil.

Do not clean O-ring with solvent.

Make sure that O-ring and its mating part are free of foreign material.

When installing O-ring, be careful not to scratch it with tool or fingernails. Also be careful not to
twist or stretch O-ring. If O-ring was stretched while it was being attached, do not insert it
quickly into fuel tube.

Insert O-ring straight into fuel tube. Do not angle or twist it.
3. Install the fuel injector to the fuel tube using the following steps.
a. Insert new clip into clip mounting groove on the fuel injector.

Insert clip so that lug “A” of fuel injector matches notch “A” of
the clip.
CAUTION:

Do not reuse clip. Replace it with a new one.

Do not allow the clip to interfere with the O-ring. If
interference occurs, replace the O-ring.
b. Insert the fuel injector into the fuel tube with the clip attached.

Insert it while matching it to the axial center.

Insert fuel injector so that lug “B” of fuel tube matches notch
“B” of the clip.

Make sure that the fuel tube flange is securely fixed in the
flange fixing groove on the clip.
c. Make sure that installation is complete by checking that fuel
injector does not rotate or come off.

Make sure that the protrusions of the fuel injectors are aligned
with the cutouts of the clips after installation.
4. Install the fuel tube and fuel injector assembly to the intake manifold.
CAUTION:
Do not let the tip of the injector nozzle come in contact with other parts.

Tighten fuel tube assembly bolts “a” to “b” in illustration in two
steps.
5. Install the fuel hose assembly.

Insert connectors straight, making sure that the axis is lined up with fuel tube side to prevent O-ring
from being damaged.

Tighten the bolts evenly in several steps.

Make sure that there is no gap between the flange and fuel tube after tightening the bolts.
CAUTION:

Handle O-ring with bare hands. Do not wear gloves.Fuel tube side : Blue
Nozzle side : Brown
KBIA2507E
1st step : 12.8 N·m (1.3 kg-m, 9 ft-lb)
2nd step : 24.5 N·m (2.5 kg-m, 18 ft-lb)
KBIA2474E

EM-32Revision: August 2007
FUEL INJECTOR AND FUEL TUBE
2004 QX56

Lubricate O-ring with new engine oil.

Do not clean O-ring with solvent.

Make sure that O-ring and its mating part are free of foreign material.

When installing O-ring, be careful not to scratch it with tool or fingernails. Also be careful not to
twist or stretch O-ring. If O-ring was stretched while it was being attached, do not insert it
quickly into fuel tube.

Insert new O-ring straight into fuel tube. Do not twist it.
6. Installation of the remaining components is in the reverse order of removal.
INSPECTION AFTER INSTALLATION
After installing the fuel tubes, make sure there are no fuel leaks at the connections using the following steps.
1. Apply fuel pressure to the fuel lines by turning the ignition switch ON (with engine stopped). Then check
for fuel leaks at the connections.
NOTE:
Use mirrors for checking on hidden points.
2. Start the engine and rev it up and check for fuel leaks at connections.
CAUTION:
Do not touch the engine immediately after stopping, as engine becomes extremely hot.

CYLINDER HEAD
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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