Infiniti F50. Manual - part 533

INTAKE MANIFOLD

EM-19

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6.

Move cooling fan fluid reservoir tank.

7.

Remove or disconnect intake manifold upper, wiring harnesses, brackets, vacuum hose, vacuum gallery
and PCV hose and tube.

CAUTION:

Cover engine openings to avoid entry of foreign materials.

8.

Disconnect water hoses.

9.

Remove electric throttle control actuator loosening fixing bolts diagonally.

CAUTION:

Handle carefully to avoid any shock.

10. Loosen bolts in reverse order of illustration to remove intake

manifold upper assembly with power tool.

11. Loosen bolts in reverse order of illustration to remove intake

manifold lower assembly with power tool.

INSPECTION AFTER REMOVAL
Surface Distortion

Using straightedge and feeler gauge, inspect surface distortion of
intake manifold lower and intake manifold upper.

INSTALLATION

Install in the reverse order of removal paying attention to the following.

PBIC0014E

PBIC0015E

Limit

: 0.1 mm (0.004 in)

PBIC0016E

EM-20

INTAKE MANIFOLD

Tightening Intake Manifold Lower Bolts

Tighten in numerical order as shown in the figure.

NOTE:
No.7 and 8 have longer bolt length than others.

Tightening Intake Manifold Upper Bolts

Tighten in numerical order as shown in the figure.
NOTE:
No.1 to 4 have longer bolt length than others.

Installation of Electric Throttle Control Actuator

●

Install intake manifold adapter gasket and electric throttle control actuator gasket so that three protrusions
for installation identification do not face downward.

●

Tighten fixing bolts of electric throttle control actuator equally and diagonally in several steps.

●

After installation perform procedure in 

EM-21, "INSPECTION AFTER INSTALLATION"

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Connecting Water Hose

Install water hose so that its overlap width for connection is between 27 mm (1.06 in) and 32 mm (1.26 in) (tar-
get: 27 mm, 1.06 in).

Connecting Vacuum Hose

Refer to 

EC-24, "Vacuum Hose Drawing"

 .

Connecting Quick Connector of Fuel Tube

Install quick connector as follows on engine side only.

1.

Make sure no foreign substances are deposited in and around tube and quick connector, and no damage
on them. 

2.

Thinly apply new engine oil around the fuel tube from tip end to the spool end.

3.

Align center to insert quick connector straightly into fuel tube.

●

Insert fuel tube into quick connector until edge side spool is
completely inside quick connector, and 2nd spool exposes
right below quick connector.

CAUTION:

●

Hold A position in illustration when inserting fuel tube
into quick connector.

●

Carefully align center to avoid inclined insertion to pre-
vent damage to O-ring inside quick connector.

●

Insert until you hear a “click” sound and actually feel
the engagement.

PBIC0015E

PBIC0014E

PBIC0017E

INTAKE MANIFOLD

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●

To avoid misidentification of engagement with a similar
sound, be sure to perform the next step.

4.

Pull quick connector by hand holding A position. Make sure it is
completely engaged (connected) so that it does not come out
from fuel tube. 

NOTE:
Recommended pulling force is 50 N (5.1 kg, 11.2 lb).

5.

Install quick connector cap on quick connector joint (on engine
side only).

6.

Install fuel hose and fuel tube to hose clamps.

INSPECTION AFTER INSTALLATION

●

After installing fuel tubes, make sure there is no fuel leakage at connections in the following steps.

–

a) Apply fuel pressure to fuel lines with turning ignition switch ON (with engine stopped). Then check for

fuel leaks at connections.

–

b) Start the engine and rev it up and check for fuel leaks at connections.

●

Perform procedures for “Throttle Valve Closed Position Learning” after finishing repairs. Refer to 

EC-46,

"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-46, "Idle Air Volume Learning"

 .

KBIA0272E

SBIA0354E

EM-22

EXHAUST MANIFOLD AND THREE WAY CATALYST

EXHAUST MANIFOLD AND THREE WAY CATALYST

PFP:14004

Removal and Installation

EBS00NBE

REMOVAL

1.

Remove heated oxygen sensors.

●

Follow below steps to remove each heated oxygen sensor.

a.

Remove engine undercover and engine cover with power tool. 

b.

Remove harness connector of each heated oxygen sensor, and harness from bracket and middle clamp.

c.

Using heated oxygen sensor wrench, remove both left and right
heated oxygen sensors.

CAUTION:

●

Be careful not to damage heated oxygen sensor.

●

Discard any heated oxygen sensor which has been
dropped from a height of more than 0.5 m (19.7 in) onto a
hard surface such as a concrete floor; use a new one.

2.

Remove exhaust manifold and three way catalyst (left bank) in
below steps.

a.

Remove A/C compressor with power tool and put aside with pip-
ing connected. Refer to 

ATC-144, "Compressor"

 .

b.

Remove exhaust front tube with power tool. Refer to 

EX-3, "Removal and Installation"

 .

c.

Remove steering lower joint to enable steering shaft to move freely.

d.

Support and lift up bottom of engine with transmission jack. Remove left engine mount insulator along with
left engine mount brackets.

1.

Heated oxygen sensor 1 (bank 2)

2.

Exhaust manifold cover (right bank)

3.

Exhaust manifold and three way cat-
alyst (right bank)

4.

Gasket

5.

Exhaust manifold and three way cat-
alyst (left bank)

6.

Exhaust manifold cover (left bank)

7.

Heated oxygen sensor 1 (bank1)

SBIA0355E

PBIC1000E