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

Intake Manifold: Service and Repair






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. Refer to Powertrain Management; Fuel Delivery and Air Induction; Fuel Pressure Release.
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 the fuel quick connector on the engine side.
^ Using the quick connector release tool (hereinafter called "release tool"), perform the following steps to disconnect quick connector.





a. Remove quick connector cap.
b. With the sleeve side of release facing quick connector, install release tool onto fuel tube.
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 in illustration.
^ 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 hose quick connector, on the vehicle piping side, using the quick connector release tool (here after called "release tool"). Perform the following steps to disconnect the vehicle piping side connector.
a. With the sleeve side of release facing quick connector, install release tool onto fuel tube.
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 the quick connector while holding it at the "A" position, as shown.
^ Do not pull with lateral force applied or 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 the 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.





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





13. Loosen the bolts in the order shown to remove the intake manifold assembly.

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
Installation is in the reverse order of removal. Pay attention to the following for installation.

Tightening Intake Manifold Bolts and Nuts

Intake Manifold Sequence:





^ Install the intake manifold bolts and nuts in the numerical order of the tightening sequence 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 Quick Connector on the Fuel Hose (Engine Side)
^ Install the engine side quick connector as follows.
1. Make sure no foreign substances are deposited in and around the fuel tube and quick connector, and there is no damage to them.
2. Thinly apply new engine oil around the fuel tube lip 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 at position "A" as shown, when inserting the fuel tube into the quick connector.
^ Carefully align to center to avoid inclined insertion to prevent damage to the O-ring inside the quick connector.
^ Insert the fuel tube 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 the fuel hose with the hose clamp, pull the 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 lbs.).

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 Quick Connector on the Fuel Hose (Vehicle Piping Side)
^ Install the vehicle piping side quick connector as follows.
7. Make sure no foreign substances are deposited in and around the fuel tube and quick connector, and there is no damage to 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:
^ Carefully align to center to avoid inclined insertion to prevent damage to the O-ring inside the quick connector.
^ Insert the tube 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 the fuel hose with the hose clamp, pull the 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 lbs.).

11. Install the fuel hose to the hose clamp.

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 stopping as engine is extremely hot.

^ Perform procedures for "Throttle Valve Closed Position Learning" after finishing repairs. Refer to Powertrain Management; Computers and Control Systems.
^ If electric throttle control actuator is replaced, perform procedures for "Idle Air Volume Learning" after finishing repairs. Refer to Powertrain Management; Computers and Control Systems.
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