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Home >> Nissan-Datsun >> 2002 >> Altima 2.5 SL L4-2.5L (QR25DE) >> Repair and Diagnosis >> Engine, Cooling and Exhaust >> Engine >> Intake Manifold >> Service and Repair

Intake Manifold: Service and Repair

Collector Sequence:






REMOVAL

WARNING: To avoid the danger of being scalded, never drain the coolant when the engine is hot.

1. Disconnect the negative battery terminal.
2. Release the fuel pressure.
3. Drain coolant when engine is cooled.
4. Disconnect the MAP sensor electrical connector.
5. Remove air cleaner case and air duct assembly.
6. Disconnect the following components at the intake side:
a. PCV hose
b. EVAP canister purge volume control solenoid
c. Electric throttle control actuator
d. Brake booster vacuum hose
7. Disconnect fuel hose quick connector on the vehicle engine side.





^ Using the quick connector release tool (here after called "release tool"), and perform the following steps to disconnect the fuel tube quick connector.





a. Remove quick connector cap.





b. With the sleeve side of release facing quick connector, install release tool onto the fuel tube as shown.
c. Insert release tool into quick connector until sleeve contacts and goes no further. Hold the release tool on that position.

CAUTION: Inserting the release tool hard will not disconnect quick connector. Hold release tool where it contacts and goes no further.

d. Pull the quick connector straight out from the fuel tube.

CAUTION:
^ Pull quick connector holding it at the "A" position, as shown.
^ Do not pull with lateral force applied. O-ring inside quick connector may be damaged.
^ Prepare container and cloth beforehand as fuel will leak out.
^ Avoid fire and sparks.
^ Be sure to cover openings of disconnected pipes with plug or plastic bag to avoid fuel leakage and entry of foreign materials.

8. If necessary, disconnect the fuel tube, on the vehicle piping side, using the quick connector release tool (here after called "release tool"). Perform the following steps to disconnect the fuel tube Quick connector.





a. With the sleeve side of the release facing quick connector, install release tool onto the fuel tube as shown.
b. Insert release tool into quick connector until sleeve contacts and goes no further. Hold the release tool on that position.

CAUTION: Inserting the release tool hard will not disconnect quick connector. Hold release tool where it contacts and goes no further.

c. Pull the quick connector straight out off of the fuel tube.

CAUTION:
^ Pull quick connector holding it at the "A" position, as shown.
^ Do not pull with lateral force applied as the O-ring inside the quick connector may be damaged.
^ Prepare a container and cloth beforehand as fuel will leak out.
^ Avoid fire and sparks.
^ Be sure to cover openings of disconnected pipes with plug or plastic bag to avoid fuel leakage and entry of foreign materials.

9. Loosen mounting bolts diagonally, and remove the electric throttle control actuator.

CAUTION: Handle carefully to avoid any damage.

10. Disconnect intake manifold collector harness, and vacuum hose.

CAUTION: Cover engine openings to avoid entry of foreign materials.

11. Remove intake manifold collector mounting bolts on the support, using power tools.





12. Loosen the mounting bolts and nuts in the order shown to remove the intake manifold collector, using power tools.





13. Loosen the bolts in the order shown to remove the intake manifold assembly, using power tools.

INSPECTION AFTER REMOVAL
Surface Distortion





^ Using straightedge and feeler gauge, inspect surface distortion of intake manifold collector and intake manifold surface.
Standard: 0.1 mm (0.004 inch)

INSTALLATION
^ Install the intake manifold bolts and nuts in the reverse order of removal, following the tightening sequences below.

Tightening Intake Manifold Bolts and Nuts

Intake Manifold Sequence:





^ Tighten in numerical order as shown.

CAUTION: After tightening No.5, retighten the No.1 mounting bolt to specification.

Tightening Intake Manifold Collector Bolts and Nuts





^ Tighten in numerical order as shown.

CAUTION: After tightening No.7, retighten the No.1 mounting bolt to specification.

Installation of Electric Throttle Control Actuator:
^ Tighten the mounting bolts of electric throttle control actuator equally and diagonally in several steps.
Electric throttle control actuator mounting bolts: 7.2 - 9.6 Nm (0.74 - 0.98 kg-m, 64 - 84 inch lbs.)
^ After installation perform procedure, "Inspection After Installation".

Connecting the Quick Connector for the Fuel Hose (Engine Side)
Install the fuel tube quick connector (engine side) as follows.
1. Make sure no foreign substances are deposited in and around tube and quick connector and there is no damage on them.
2. Thinly apply new engine oil around the fuel tube tip end.





3. Align center to insert quick connector straight into fuel tube.
^ Insert fuel tube into quick connector until the top spool on fuel tubes is inserted completely and the second level spool is positioned slightly below the quick connector bottom end.

CAUTION: Hold A position in illustration when inserting fuel tube into quick connector.
^ Carefully align center to avoid inclined insertion to prevent damage to O-ring inside quick connector.
^ Insert until you hear a "click" sound and actually feel the engagement.
^ To avoid misidentification of engagement with a similar sound, be sure to perform the next step.
4. Before clamping fuel hose with hose clamp, pull quick connector hard by hand holding at the "A" position, as shown. Make sure it is completely engaged (connected) so that it does not come off of the fuel tube.

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

5. Install quick connector cap on quick connector joint.





^ Direct arrow mark on quick connector cap to upper side (fuel hose side).
6. Install fuel hose to hose clamp.

Connecting the Quick Connector for the Fuel Hose (Vehicle Piping Side)
Install the fuel tube quick connector (vehicle piping side side) as follows.
7. Make sure no foreign substances are deposited in and around tube and quick connector and there is no damage on them.
8. Thinly apply new engine oil around the fuel tube tip end.





9. Align center to insert quick connector straight into fuel tube.
^ Insert fuel tube into quick connector until the top spool on fuel tubes is inserted completely and the paint mark is positioned slightly below the quick connector bottom end.

CAUTION:
^ Hold A position in illustration when inserting fuel tube into quick connector.
^ Carefully align center to avoid inclined insertion to prevent damage to O-ring inside quick connector.
^ Insert until you hear a "click" sound and actually feel the engagement.
^ To avoid misidentification of engagement with a similar sound, be sure to perform the next step.

10. Before clamping fuel hose with hose clamp, pull quick connector hard by hand. Make sure it is completely engaged (connected) so that it does not come off of the fuel tube.

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

INSPECTION AFTER INSTALLATION
Check connections for fuel leakage.
1. Start the engine and run it for a few minutes with the engine at idle.
2. Stop the engine and check for fuel leakage both visually and by odor of gasoline.

NOTE: Use mirrors for checking on connections out of the direct line of sight.

CAUTION: Do not touch engine immediately after stopped as engine becomes extremely hot.

^ Perform procedures for "Throttle Valve Closed Position Learning" after finishing repairs. Refer to Computers and Control Systems / Engine Control Module / Throttle Valve Closed Position Learning:
Throttle Valve Closed Position Learning

^ If electric throttle control actuator is replaced, perform procedures for "Idle Air Volume Learning" after finishing repairs. Refer to Computers and Control Systems / Engine Control Module / Idle Air Volume Learning:
Programming and Relearning
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