2005 INFINITI QX4 fuel

EXHAUST MANIFOLD AND THREE WAY CATALYST
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EXHAUST MANIFOLD AND THREE WAY CATALYSTPFP:14004
Removal and InstallationEBS00LM2
REMOVAL
WA RN ING:
Perform the work when the exhaust and cooling system have cooled sufficiently.
1. Remove the air duct and resonator assembly. Refer to EM-14, "
REMOVAL" .
2. Drain the engine coolant from the radiator. Refer to MA-13, "
DRAINING ENGINE COOLANT" .
3. Remove the engine undercover using power tool.
4. Remove the radiator and radiator hoses. Refer to CO-12, "
RADIATOR" .
5. Remove the drive belts. Refer to EM-12, "
Removal" .
6. Remove the air fuel ratio A/F sensors (right bank, left bank).

Follow steps below to remove each air fuel ratio A/F sensor.
a. Remove the engine room cover using power tool. Refer to EM-11, "
REMOVAL" .
b. Remove the harness connector of each air fuel ratio A/F sensor, and harness from bracket and middle
clamp.
1. Air fuel ratio (A/F) sensor 1 (bank 2) 2. Exhaust manifold cover (bank 2) 3. Exhaust manifold (bank 2)
4. Gaskets 5. Exhaust manifold (left bank 1) 6. Exhaust manifold cover (bank 1)
7. Air fuel ratio (A/F) sensor 1 (bank 1)
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EM-20Revision: October 2005
EXHAUST MANIFOLD AND THREE WAY CATALYST
2005 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) following the steps
below.
a. Remove the exhaust front tube. Refer to EX-3, "
Removal and
Installation" .
b. Remove the exhaust manifold cover.
c. Loosen the nuts in reverse order of illustration using power tool.
d. Remove the exhaust studs from positions 2, 4, 6, 8 and remove
left exhaust manifold
9. Remove the exhaust manifold (right bank) following the steps
below.
a. Remove the exhaust front tube. 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 of illustration using power tool.
e. Remove the exhaust studs from positions 2, 4, 6, 8 and remove right exhaust manifold.
INSPECTION AFTER REMOVAL
Surface Distortion

Check the flatness of each exhaust manifold flange surface
using suitable tools.

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

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

EXHAUST MANIFOLD AND THREE WAY CATALYST
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Revision: October 20052005 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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FUEL INJECTOR AND FUEL TUBEPFP:16600
Removal and InstallationEBS00LM6
CAUTION:
Do not remove or disassemble parts unless instructed as shown in the figure.
REMOVAL
1. Remove the engine room cover using power tool. Refer to EM-11, "REMOVAL" .
2. Release the fuel pressure. Refer to EC-93, "
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:

While hoses are disconnected, plug them 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)
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FUEL INJECTOR AND FUEL TUBE
2005 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 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.
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Reference value :130 N (13.3 kg, 29.2 lb)
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FUEL INJECTOR AND FUEL TUBE
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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 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 the 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 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
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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)
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FUEL INJECTOR AND FUEL TUBE
2005 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 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 the connections.
CAUTION:
Do not touch the engine immediately after stopping, as engine becomes extremely hot.

EM-58Revision: October 2005
CYLINDER HEAD
2005 QX56
CYLINDER HEADPFP:11041
On-Vehicle ServiceEBS00LME
CHECKING COMPRESSION PRESSURE
1. Warm up the engine thoroughly. Then stop the engine.
2. Release the fuel pressure. Refer to EC-93, "
FUEL PRESSURE RELEASE" .
CAUTION:
Leave the fuel pump fuse disconnected until step 7.
3. Remove the spark plug from each cylinder. Refer to EM-27, "
REMOVAL" .
4. Connect the engine tachometer (not required in use of CONSULT-II).
5. Install the compression tester with Tool into the spark plug hole.
6. With the accelerator pedal fully depressed, turn the ignition
switch to “START” for cranking. When the gauge pointer stabi-
lizes, read the compression pressure and engine rpm. Perform
these steps to check each cylinder.
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 the specified range, check the battery liquid for proper gravity. Check the
engine speed again with normal battery gravity.

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

If some cylinders have low compression pressure, pour a 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 a 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 a valve in adjacent cylinders
may be damaged. Inspect and repair as required.
7. Install the components in the reverse order of removal.
8. Start the engine and confirm that it runs smoothly.
9. Perform trouble diagnosis. If DTC appears, erase it. Refer to EC-95, "
TROUBLE DIAGNOSIS" . Tool number : EG15050500 (J-45402)
Standard MinimumDeference limit
between cylinders
1,520 (15.5, 220) / 200 1,324 (13.5, 192) / 200 98 (1.0, 14) / 200
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