2008 INFINITI QX56 fuel pressure

COMPRESSION PRESSUREEM-23
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COMPRESSION PRESSURE
Checking Compression PressureINFOID:0000000001538811
1. Warm up the engine thoroughly. Then stop the engine.
2. Release the fuel pressure. Refer to EC-494, "
Fuel Pressure Check".
CAUTION:
If CONSULT-III 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-16, "
Removal and Installation".
4. Connect the engine tachometer (not required in use of CONSULT-III).
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, t he 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-75, "
Description".
Tool number : EG15050500 (J-45402)
Standard
MinimumDeference limit be-
tween cylinders
1,520 (15.5, 220) / 200 1,324 (13.5, 192) / 200 98 (1.0, 14) / 200WBIA0605E
Revision: March 2010 2008 QX56

EM-26
< ON-VEHICLE REPAIR >
INTAKE MANIFOLD
INTAKE MANIFOLD
Removal and InstallationINFOID:0000000001538814
REMOVAL
1. Partially drain the engine coolant. Refer to CO-11, "Changing Engine Coolant".
WARNING:
To avoid the danger of being scal ded, never drain the engine coolant when the engine is hot.
2. Remove the engine room cover using power tool. Refer to EM-24, "
Removal and Installation".
3. Release the fuel pressure. Refer to EC-494, "
Fuel Pressure Check".
4. Remove the air duct and resonator assembly. Refer to EM-25, "
Removal and Installation".
5. Disconnect the fuel tube quick connector on the engine side.
1. Intake manifold 2. PCV hose 3. Gasket
4. Electric throttle control actuator 5. Water hose 6. Water hose
7. PCV hose 8. EVAP hose 9. EVAP canister purge control solenoid
valve
10. Bracket 11. Gasket
KBIA2461E
LBIA0395E
Revision: March 2010 2008 QX56

INTAKE MANIFOLDEM-29
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5. Install the quick connector cap on the quick connector joint (on
engine side only).
6. Install the fuel hose and tube to hose clamps.
7. Refill the engine coolant. Refer to CO-11, "
Changing 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-18,
"Throttle Valve Closed Position Learning".
• If electric throttle control actuator is replaced, per form procedures for “Idle Air Volume Learning” after finish-
ing repairs. Refer to EC-18, "
Idle Air Volume Learning".
SBIA0354E
Revision: March 2010 2008 QX56

EM-40
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FUEL INJECTOR AND FUEL TUBE
FUEL INJECTOR AND FUEL TUBE
Removal and InstallationINFOID:0000000001538819
CAUTION:
Do not remove or disassemble parts unless instructed as shown.
REMOVAL
1. Remove engine room cover using power tool. Refer to EM-24, "Removal and Installation".
2. Release fuel pressure. Refer to EC-494, "
Fuel Pressure Check".
3. Disconnect the negative battery terminal.
4. Disconnect fuel injector harness connectors.
5. Disconnect fuel hose assembly from fuel tube (RH bank and LH bank). CAUTION:
• While hoses are disconnected, plug th em to prevent fuel from draining.
• Do not separate fuel co nnector and fuel hose.
6. Remove fuel injectors with fuel tube assembly.
1. Fuel tube (RH bank) 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 bank)
KBIA2472E
Revision: March 2010 2008 QX56

FUEL INJECTOR AND FUEL TUBEEM-41
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7. Remove fuel injector from fuel tube.
a. Spread open to remove clip.
b. Remove 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 fuel damper from each fuel tube.
INSTALLATION
1. Install fuel damper to each fuel tube.
a. Apply engine oil to O-ring and set it into the cap of 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, be car eful not to scratch it with
tool or fingernails. Also be careful not to twist or stretch
O-ring.
b. Make sure that backup spacer is in the O-ring connecting sur- face of fuel damper.
NOTE:
Backup spacer is fuel damper assembly part.
c. Insert fuel damper until it seats on fuel tube. CAUTION:
• Insert straight, making sure that the axis is lined up.
• Do not pressure-fit with excessive force.
d. Install cap, and then tighten bolts evenly by turns. • After tightening bolts, make sure that there is no gap between cap and fuel tube.
2. Install O-rings to fuel injector paying attention to the items below. CAUTION:
• Upper and lower O-ring are different.
• Handle O-ring with bare hands. Never wear gloves.
KBIA2506E
Reference value :130 N (13.3 kg, 29.2 lb)
Fuel tube side : Blue
Nozzle side : Brown
KBIA2473E
Revision: March 2010 2008 QX56

EM-42
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FUEL INJECTOR AND FUEL TUBE
• 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 stretc hed 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 fuel injector to fuel tube.
a. Insert clip into clip mounting groove on fuel injector. • Insert clip so that lug “A” of fuel injector matches notch “A” ofthe clip.
CAUTION:
• Do not reuse clip. Replace it with a new one.
• Be careful to keep clip from interfering with O-ring. Ifinterference occurs, replace O-ring.
b. Insert fuel injector into fuel tube with 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 fuel tube flange is securely fixed in flange fixing groove on clip.
c. Make sure that installation is complete by checking that fuel injector does not rotate or come off.
• Make sure that protrusions of fuel injectors are aligned withcutouts of clips after installation.
4. Install fuel tube and fuel injector assembly to intake manifold. CAUTION:
Be careful not to let tip of injector nozzle come in contact with other parts.
• Tighten fuel tube assembly bolts “a” to “b” in illustration and in
two steps.
5. Install fuel hose assembly. • Follow the precautions for fuel injector when handling O-ring.
• 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 flange and fuel tube after tightening bolts.
6. Installation of the remaining components is in the reverse order of removal.
INSPECTION AFTER INSTALLATION
After installing fuel tubes, make sure there are no fuel leaks at connections using the following steps.
1. Apply fuel pressure to fuel lines by turning ignition switch ON (with engine stopped). Then check for fuel leaks at connections.
2. Start the engine and rev it up and check for fuel leaks at connections. NOTE:
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
Revision: March 2010 2008 QX56

EM-52
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TIMING CHAIN
a. Apply engine oil onto the threaded parts of the bolt and seating area.
b. Select the one most visible notch of the four on the bolt flange.Corresponding to the selected notch, put a alignment mark
(such as paint) on the crankshaft pulley.
14. Rotate the crankshaft pulley in normal direction (clockwise when viewed from engine front) to check for parts interference.
15. Installation of the remaining components is in the reverse of order of removal.
INSPECTION AFTER INSTALLATION
• Before starting engine, check oil/fluid levels incl uding engine coolant and engine oil. If less than required
quantity, fill to the specified level. Refer to MA-12, "
Fluids and Lubricants".
• Use procedure below to check for fuel leakage.
• Turn ignition switch ON (with engine stopped). With fuel pressure applied to fuel piping, check for fuel leak- age at connection points.
• Start engine. With engine speed increased, che ck 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 including
engine oil and engine coolant.
• Bleed air from passages in lines and hoses, such as in cooling system.
• After cooling down engine, again check oil/fluid levels including engine oil and engine coolant. Refill to spec-
ified level, if necessary.
• Summary of the inspection items:
*Power steering fluid, brake fluid, etc.
Crankshaft pulley bolt torque
Step 1 : 93.1 N·m (9.5 kg-m, 69 ft-lb)
Step 2 : additional 90 ° (angle tightening)
KBIA2519E
Item Before starting engine Engine runningAfter engine stopped
Engine coolant LevelLeakage Level
Engine oil LevelLeakage Level
Transmission/
transaxle fluid A/T and CVT Models
LeakageLevel/Leakage Leakage
M/T Models Level/Leakage LeakageLevel/Leakage
Other oils and fluids* LevelLeakage Level
Fuel LeakageLeakage Leakage
Exhaust gas —Leakage —
Revision: March 2010 2008 QX56

CAMSHAFTEM-63
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1. Check engine oil level. Refer to
LU-8, "Inspection".
2. Perform the following procedure so as to prevent the engine from being unintentionally started while checking.
a. Release fuel pressure. Refer to EC-494, "
Fuel Pressure Check".
b. Disconnect ignition coil and injector harness connectors if practical.
3. Remove IVT control solenoid valve.
4. Crank engine, and then make sure that engine oil comes out from IVT control cover oil hole. End cranking after checking.
WARNING:
Be careful not to touch rotating parts (drive be lts, idler pulley, and crankshaft pulley, etc.).
CAUTION:
• Engine oil may squirt from IVT control solenoid valve installation hole during cranking. Use a
shop cloth to prevent engine oil from splash ing on worker, engine components and vehicle.
• Do not allow engine oil to get on rubber components such as drive belts or engine mount insula- tors. Immediately wipe off any splashed engine oil.
5. Clean oil groove between oil strainer and IVT control solenoid valve if engine oil does not come out from IVT control valve cover oil hole. Refer to LU-7, "
Schematic".
6. Remove components between IVT control solenoid valve and camshaft sprocket (INT), and then check each oil groove for clogging.
• Clean oil groove if necessary.
7. After inspection, installation of the remaining components is in the reverse order of removal.
Revision: March 2010 2008 QX56