2006 INFINITI QX56 fuel pressure

EM-20Revision: November 2009
INTAKE MANIFOLD
2006 QX56
5. Install the quick connector cap on the quick connector joint (onengine side only).
6. Install the fuel hose and tube to hose clamps.
7. Refill the engine coolant. Refer to CO-11, "
REFILLING ENGINE
COOLANT" .
INSPECTION AFTER INSTALLATION

After installing fuel tubes, make sure there is no fuel leakage at connections in the following steps.
–Apply fuel pressure to fuel lines by turning ignition switch ON (with engine stopped). Then check for fuel
leaks at connections.
–Start the engine and rev it up and check for fuel leaks at the connections.

Perform procedures for “Throttle Valve Closed Position Learning ” after finishing repairs. Refer to EC-78,
"Throttle Valve Closed Position Learning" .

If electric throttle control actuator is replaced, perform procedures for “Idle Air Volume Learning” after fin-
ishing repairs. Refer to EC-78, "
Idle Air Volume Learning" .
SBIA0354E

FUEL INJECTOR AND FUEL TUBEEM-31
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Revision: November 2009 2006 QX56
FUEL INJECTOR AND FUEL TUBEPFP:16600
Removal and InstallationEBS00RF5
CAUTION:
Do not remove or disassemble parts unless instructed as shown.
REMOVAL
1. Remove the engine room cover using power tool. Refer to EM-12, "REMOVAL" .
2. Release the fuel pressure. Refer to EC-80, "
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 (RH and LH).
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 (RH) 2. Cap3. 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 (LH)
KBIA2472E

EM-32Revision: November 2009
FUEL INJECTOR AND FUEL TUBE
2006 QX56
7. Remove the fuel injector from the fuel tube using the followingsteps.
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 cup 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-rings are different colors.
KBIA2506E
Reference value :130 N (13.3 kg, 29.2 lb)
Fuel tube side : Blue
Nozzle side : Brown
KBIA2473E

EM-34Revision: November 2009
FUEL INJECTOR AND FUEL TUBE
2006 QX56

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.

CYLINDER HEADEM-63
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Revision: November 2009 2006 QX56
CYLINDER HEADPFP:11041
On-Vehicle ServiceEBS00RFD
CHECKING COMPRESSION PRESSURE
1. Warm up the engine thoroughly. Then stop the engine.
2. Release the fuel pressure. Refer to EC-80, "
FUEL PRESSURE RELEASE" .
CAUTION:
If CONSULT-II is not used to release fuel pressure leave the fuel pump fuse disconnected until
step 7.
3. Remove the spark plug from each cylinder. Refer to EM-29, "
Removal and Installation" .
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 LAN-26, "
CAN COMMUNICATION" .
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
WBIA0605E

EM-74Revision: November 2009
ENGINE ASSEMBLY
2006 QX56
ENGINE ASSEMBLYPFP:10001
Removal and InstallationEBS00RFH
WARNING:

Situate vehicle on a flat and solid surface.

Place chocks at front and back of rear wheels.

For engines not equipped with engine slingers, attach proper slingers and bolts described in
PARTS CATALOG.
CAUTION:

Always be careful to work safely, avoid forceful or uninstructed operations.

Do not start working until exhaust system and engine coolant are cooled sufficiently.

If items or work required are not covered by the engine section, refer to the applicable sections.

Always use the support point specified for lifting.

Use either 2-point lift type or separate type lift. If board-on type is used for unavoidable reasons,
support at the rear axle jacking point with transmission jack or similar tool before starting work, in
preparation for the backward shift of center of gravity.

For supporting points for lifting and jacking point at rear axle, refer to GI-41, "Garage Jack and
Safety Stand" .
REMOVAL
Preparation
1. Drain the engine coolant. Refer to CO-11, "DRAINING ENGINE COOLANT" .
2. Partially drain the A/T fluid. Refer to AT- 1 2 , "
Changing Automatic Transmission Fluid (ATF)" .
3. Release the fuel pressure. Refer to EC-80, "
FUEL PRESSURE RELEASE"
1. Rear engine mounting insulator 4WD 2. Rear engine mounting insulator 2WD 3. LH engine mounting bracket
4. LH heat shield plate 5. LH engine mounting insulator 6. RH engine mounting bracket
7. RH heat shield plate 8. RH engine mounting insulator
LBIA0397E

EM-76Revision: November 2009
ENGINE ASSEMBLY
2006 QX56

Loosen the bolts diagonally.
CAUTION:

Be careful not to damage the drive plate. Especially
avoid deforming and damaging of the signal plate teeth
(circumference position).

Place the drive plate with the signal plate surface fac-
ing other than downward.

Keep magnetic materials away from the signal plate.
CAUTION:
Use an engine stand that has a load capacity [approximately 240kg (529 lb) or more] large enough
for supporting the engine weight.

If the load capacity of the stand is not adequate, remove the following parts beforehand to
reduce the potential risk of overturning the stand.
–Remove the fuel tube and fuel injector assembly. Refer to EM-31, "Removal and Installation" .
–Remove the intake manifold. Refer to EM-17, "Removal and Installation" .
–Remove the ignition coil. Refer to EM-28, "Removal and Installation" .
–Remove the rocker cover. Refer to EM-35, "Removal and Installation" .
–Other removable brackets.
CAUTION:
Before removing the hanging chains, make sure the engine stand is stable and there is no risk of
overturning.
31. Remove the alternator. Refer to SC-25, "
REMOVAL" .
32. Remove the 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.
INSPECTION AFTER INSTALLATION

Before starting the engine, check oil/fluid levels including engine coolant and engine oil. If the levels are
lower than required quantity, fill to the specified level. Refer to MA-11, "
Fluids and Lubricants" .

Use procedure below to check for fuel leakage.

Turn ignition switch ON (with engine stopped). With fuel pressure applied to the fuel piping, check for fuel
leakage at the connection points.

Start engine. With engine speed increased, check again for fuel leakage at connection points.

Run engine to check for unusual noise and vibration.

Warm up engine thoroughly to make sure there is no leakage of fuel, exhaust gas, or any oils/fluids includ-
ing engine oil and engine coolant.

Bleed air from passages in lines and hoses, such as in cooling system.

After cooling down the engine, again check oil/fluid levels including engine oil and engine coolant. Refill to
specified level if necessary.

Summary of the inspection items:
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FL-4Revision: November 2009
FUEL SYSTEM
2006 QX56
FUEL SYSTEMPFP:17503
Checking Fuel LinesEBS00M3Q
Inspect fuel lines, fuel filler cap and fuel tank for improper attach-
ment, leaks, cracks, damage, loose connections, chafing or deterio-
ration.
If necessary, repair or replace damaged parts.
General PrecautionsEBS00M3R
WARNING:
When replacing fuel line parts, be sure to observe the following.

Put a “CAUTION: INFLAMMABLE” sign in the workshop.

Be sure to work in a well ventilated area and furnish workshop with a CO2 fire extinguisher.

Do not smoke while servicing fuel system. Keep open flames and sparks away from the work area.
CAUTION:

Before removing fuel line parts, carry out the following procedures:
–Put drained fuel in an explosion-proof container and put the lid on securely. Keep the container in
safe area.
–Release fuel pressure from the fuel lines. Refer to EC-80, "FUEL PRESSURE RELEASE" .
–Disconnect the battery negative terminal.

Always replace O-rings and clamps with new ones.

Do not kink or twist hoses when they are being installed.

Do not tighten hose clamps excessively to avoid damaging
hoses.
Tighten high-pressure rubber hose clamp so that clamp
end is 3 mm (0.12 in) from hose end.
Tightening torque specifications are the same for all rubber
hose clamps.
Check that the screw does not contact adjacent parts.
SMA803A
MMA104A