2001 INFINITI QX4 Fuel

SEM950F
TIGHTENING PROCEDURESNBEM0006S01Intake ManifoldNBEM0006S0101ITighten in numerical order shown in the figure.
1. Tighten all bolts and nuts to 5 to 10 N´m (0.5 to 1.0 kg-m, 44
to 86 in-lb).
2. Finally tighten all bolts and nuts to 26 to 31 N´m (2.7 to 3.2
kg-m, 20 to 23 ft-lb).
ITighten all bolts and nuts to the final torque, evenly dividing the
tightening into at least five steps.
SEM473G
Fuel TubeNBEM0006S0102ITighten in numerical order shown in the figure.
1. Tighten all bolts to 9.3 to 10.8 N´m (0.95 to 1.1 kg-m, 83 to 95
in-lb).
2. Then tighten all bolts to 21 to 26 N´m (2.1 to 2.7 kg-m, 15 to
20 ft-lb).
SEM474G
Fuel Pressure RegulatorNBEM0006S0103Tighten fuel pressure regulator to 2.9 to 3.8 N´m (0.3 to 0.39 kg-m,
26.0 to 33.9 in-lb).
ITighten screws evenly several times to have the fuel pres-
sure regulator tightened at the specified torque.
IAlways replace O-ring with new ones.
ILubricate O-ring with new engine oil.
SEM475G
Throttle BodyNBEM0006S0105ITighten in numerical order shown in the figure.
1. Tighten all bolts to 8.8 to 10.8 N´m (0.9 to 1.1 kg-m, 79 to 95
in-lb).
2. Then tighten all bolts to 18 to 21 N´m (1.8 to 2.2 kg-m, 13 to
15 ft-lb).
SEM476G
Upper Intake Manifold CollectorNBEM0006S0107Tighten bolts and nuts to 18 to 21 N´m (1.8 to 2.2 kg-m, 13 to 15
ft-lb) in numerical order shown in the figure.
OUTER COMPONENT PARTS
Removal and Installation (Cont'd)
EM-12

NBEM0007
SEM480G
SEM481G
JEM482G
SEM387C
1. Warm up engine.
2. Turn ignition switch OFF.
3. Release fuel pressure.
Refer to EC-39, ªFuel Pressure Releaseº.
4. Remove engine cover and throttle wire.
5. Remove air duct with air cleaner case.
6. Remove harness connectors and harness brackets around
ignition coils.
7. Remove throttle body.
8. Disconnect ignition coil with power transistor harness
connectors, then remove ignition coils.
9. Remove all spark plugs.
IClean area around plug with compressed air before removing
the spark plug.
10. Attach a compression tester to No. 1 cylinder.
11. Depress accelerator pedal fully to keep throttle valve wide
open.
12. Crank engine and record highest gauge indication.
13. Repeat the measurement on each cylinder as shown above.
IAlways use a fully-charged battery to obtain specified
engine speed.
Unit: kPa (kg/cm2, psi)/rpm
Standard MinimumDifference limit between
cylinders
1,275 (13.0, 185)/300 981 (10.0, 142)/300 98 (1.0, 14)/300
14. If compression in one or more cylinders is low:
a. Pour a small amount of engine oil into cylinders through spark
plug holes.
b. Retest compression.
IIf adding oil helps compression, piston rings may be worn
or damaged. If so, replace piston rings after checking pis-
ton.
IIf pressure stays low, a valve may be sticking or seating
improperly. Inspect and repair valve and valve seat. (Refer
to SDS, EM-76 and EM-79.) If valve or valve seat is dam-
aged excessively, replace them.
IIf compression stays low in two cylinders that are next to
each other:
a) The cylinder head gasket may be leaking, or
b) Both cylinders may have valve component damage. Inspect
and repair as necessary.
15. Install parts in reverse order of removal.
16. Perform ªSelf-diagnosis Procedureº referring to EC-72, ªHow to
Erase DTCº if any DTC appears.
MEASUREMENT OF COMPRESSION PRESSURE
EM-14

ComponentsNBEM0008
SEM583G
RemovalNBEM0009WARNING:
IPlace vehicle on a flat and solid surface.
IYou should not remove oil pan until exhaust system and
cooling system have completely cooled off.
Otherwise, you may burn yourself and/or fire may break
out in the fuel line.
IWhen removing front engine mounting nuts, lift up slightly
engine for safety work.
CAUTION:
When removing the aluminum oil pan from engine, first
remove the crankshaft position sensors (POS and REF) from
the assembly.
Be careful not to damage sensor edges and signal plate teeth.
1. Remove front RH and LH wheels.
2. Remove battery.
3. Remove oil level gauge.
4. Remove engine undercover.
5. Remove suspension member stay.
6. Drain engine coolant from radiator drain plug.
7. Disconnect A/T oil cooler hoses.
8. Drain engine oil.
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OIL PAN
Components
EM-15

CAUTION:
IAfter removing timing chain, do not turn crankshaft and
camshaft separately, or valves will strike piston heads.
IWhen installing camshafts, chain tensioners, oil seals, or
other sliding parts, lubricate contacting surfaces with new
engine oil.
IApply new engine oil to bolt threads and seat surfaces
when installing camshaft sprockets and crankshaft pulley.
IBefore disconnecting fuel hose, release fuel pressure.
Refer to EC-39, ªFuel Pressure Releaseº.
IBe careful not to damage sensor edges.
IDo not spill engine coolant on drive belts.
RemovalNBEM00121. Release fuel pressure.
Refer to EC-39, ªFuel Pressure Releaseº.
2. Remove battery.
3. Remove radiator.
Refer to LC-19, ªREMOVAL AND INSTALLATIONº.
4. Drain engine oil.
5. Remove drive belts and idler pulley with brackets.
6. Remove cooling fan with bracket.
7. Remove engine cover.
8. Remove air duct with air cleaner case, collector, blow-by hose,
vacuum hoses, fuel hoses, water hoses, wires, harnesses,
connectors and so on.
9. Remove the air compressor, and tie it down using rope or the
like to keep it from interfering.
10. Remove the power steering oil pump and reservoir tank. Tie
them down using rope or the like to keep them from interfer-
ing.
11. Remove alternator.
12. Remove the following.
IVacuum gallery
IWater bypass pipe
IBrackets
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TIMING CHAIN
Components (Cont'd)
EM-23

SEM415G
17. Disconnect injector harness connectors.
18. Remove fuel tube assembly in reverse order of installation.
Refer to EM-12, ªFuel Tubeº.
SEM416G
19. Remove ignition coils.
20. Remove RH and LH rocker covers from cylinder head.
SEM417G
21. Set No. 1 piston at TDC on the compression stroke by rotat-
ing crankshaft.
IAlign pointer with TDC mark on crankshaft pulley.
SEM418G
ICheck that intake and exhaust cam nose on No. 1 cylinder are
installed as shown left.
If not, turn the crankshaft one revolution (360É) and align as
above.
SEM485G
22. Remove starter motor, and set ring gear stopper using the
mounting bolt hole.
IBe careful not to damage the signal plate teeth.
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TIMING CHAIN
Removal (Cont'd)
EM-25

SEM439G
SEM440G
17. Install RH and LH rocker covers.
Rocker cover tightening procedure:
ITighten in numerical order as shown in the figure.
a. Tighten bolts 1 to 10 in that order to 6.9 to 8.8 N´m (0.7 to 0.9
kg-m, 61 to 78 in-lb).
b. Then tighten bolts 1 to 10 as indicated in figure to 6.9 to 8.8
N´m (0.7 to 0.9 kg-m, 61 to 78 in-lb).
18. Hang engine using the right and left side engine slingers with
a suitable hoist.
19. Set a suitable transmission jack under the suspension mem-
ber.
20. Remove right and left side engine mounting nuts.
21. Remove right and left side suspension member bolts.
22. Install aluminum oil pan. Refer to EM-18, ªInstallationº.
23. Set ring gear stopper using the mounting bolt hole.
IBe careful not to damage the signal plate teeth.
SEM417G
24. Install crankshaft pulley to crankshaft.
IAlign pointer with TDC mark on crankshaft pulley.
SEM531G
25. Install crankshaft pulley bolt.
ILubricate thread and seat surface of the bolt with new
engine oil.
a. Tighten to 39 to 49 N´m (4.0 to 5.0 kg-m, 29 to 36 ft-lb).
b. Put a paint mark on the crankshaft pulley.
SEM963E
c. Again tighten by turning 60É to 66É, about the angle from one
hexagon bolt head corner to another.
26. Install camshaft position sensor (PHASE), crankshaft position
sensors (REF)/(POS) and CVTC sensors.
27. Reinstall removed parts in the reverse order of removal.
IWhen installing fuel tube and intake manifold collectors, refer
to EM-12, ªTIGHTENING PROCEDURESº.
IAfter starting engine, keep idling for three minutes. Then
rev engine up to 3,000 rpm under no load to purge air from
the high-pressure chamber of the chain tensioners. The
engine may produce a rattling noise. This indicates that
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TIMING CHAIN
Installation (Cont'd)
EM-33

Removal and InstallationNBEM0042WARNING:
ISituate vehicle on a flat and solid surface.
IPlace chocks at front and back of rear wheels.
IDo not remove engine until exhaust system has com-
pletely cooled off. Otherwise, you may burn yourself
and/or fire may break out in fuel line.
IFor safety during subsequent steps, the tension of wires
should be slackened against the engine.
IBefore disconnecting fuel hose, release fuel pressure
from fuel line.
Refer to EC-39, ªFuel Pressure Releaseº.
IBefore removing front axle from transmission, place
safety stands under designated front supporting points.
Refer to GI section for lifting points and towing.
IBe sure to hoist engine and transmission in a safe man-
ner.
IFor engines not equipped with engine slingers, attach
proper slingers and bolts described in PARTS CATALOG.
CAUTION:
IWhen lifting engine, be careful not to strike adjacent parts,
especially accelerator wire casing, brake lines, and brake
master cylinder.
IIn hoisting the engine, always use engine slingers in a
safe manner.
IBefore separating engine and transmission, remove
crankshaft position sensor (POS) from the assembly.
IAlways take extra care not to damage edge of crankshaft
position sensor (POS), or ring gear teeth.GI
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ENGINE ASSEMBLY
Removal and Installation
EM-57

Rear Engine MountingNBEM0042S0102
SEM459G
SEM605G
SEM461G
SEM324F
1. Release fuel pressure.
Refer to EC-39, ªFuel pressure releaseº.
2. Remove engine hood and front RH and LH wheels.
3. Remove engine undercover and suspension member stay.
4. Drain coolant from radiator.
5. Remove the following parts.
IRadiator shroud
IRadiator
ICooling fan
IDrive belts
IBattery
IEngine cover
IThrottle wires
6. Air duct with air cleaner case.
7. Disconnect vacuum hoses, fuel hoses, heater hoses, EVAP
canister hoses, harnesses, connectors and so on.
8. Remove air conditioner compressor from bracket, then put it
aside holding with a suitable wire.
9. Remove power steering oil pump and reservoir tank with
bracket, then put it aside holding with a suitable wire.
10. Remove alternator.
11. Remove exhaust front tube heat insulators, then remove rear
heated oxygen sensors.
12. Remove exhaust front and rear tubes.
Refer to FE-8, ªRemoval and Installationº.
13. Remove transmission with transfer.
Refer to AT-277, ªRemovalº.
14. Remove TWC (manifold) heat insulators, then remove TWC
(manifold).
15. Install engine slingers.
16. Hoist engine with engine slingers and remove front engine
mounting nuts.
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ENGINE ASSEMBLY
Removal and Installation (Cont'd)
EM-59