Fuel Rail Assembly Overview

Fuel Rail Assembly Overview

CAUTION!
Fuel system is under pressure! Before opening high pressure components of the fuel injection system, the fuel pressure must be relieved to residual pressure, procedures. Refer to --> [ High Side Fuel Pressure Releasing ] High Side Fuel Pressure Releasing.





1 Fuel Injector

• Cylinder 1 fuel injector, (N30).

• Cylinder 2 fuel injector, (N31).

• Cylinder 3 fuel injector, (N32).

• Cylinder 4 fuel injector, (N33).

• With combustion chamber seal (Teflon seal), always replace, refer to --> [ Fuel Injector Combustion Chamber Teflon Seal ] Fuel Injector Combustion Chamber Teflon Seal.

• Replace O-rings.

• Note correct installed position.

• Fuel injector individual parts, refer to --> [ Fuel Injector Individual Parts ].

• Removing and installing, refer to --> [ Fuel Injectors ] Fuel Injectors.

• Cleaning, refer to --> [ Fuel Injectors, Cleaning ] Procedures.

2 Support Ring

3 Fuel Rail

• Removing and installing, refer to --> [ Intake Manifold with Fuel Rail ] Intake Manifold With Fuel Rail.

• Fuel rail, separating from the intake manifold. Refer to --> [ Fuel Rail, Separating from the Intake Manifold ] Intake Manifold With Fuel Rail.

4 High Pressure Pump

• An electric fuel pump, located in the fuel tank, supplies fuel to the mechanical high pressure pump at a pressure of approximately 7 bar.

• When installing the high pressure pump, make sure that no dirt enters the fuel system.

• The fuel system must be pressureless to install the high pressure pump, releasing fuel pressure. Refer to --> [ High Side Fuel Pressure Releasing ] High Side Fuel Pressure Releasing.

• Install the fuel line to the fuel rail free from tension.

• High pressure pump with fuel pressure regulator valve assembly overview. Refer to --> [ High Pressure Pump with Fuel Pressure Regulator Valve Assembly Overview ] High Pressure Pump With Fuel Pressure Regulator Valve Assembly Overview.

• Removing and installing, refer to --> [ High Pressure Pump ] High Pressure Pump.

5 Roller Tappet

• Remains inserted in the cylinder head after removing the high pressure pump, removable.

6 Fuel Pressure Regulator Valve (N276)

• High pressure pump with fuel pressure regulator valve assembly overview. Refer to --> [ High Pressure Pump with Fuel Pressure Regulator Valve Assembly Overview ] High Pressure Pump With Fuel Pressure Regulator Valve Assembly Overview.

7 Bolts, 10 Nm

• For the high pressure pump.

• Always replace.

8 Connecting Piece, 22 Nm

• For the high pressure fuel line.

- Check the connection tightening specification before installing the fuel high pressure line.

• Always replace.

9 High Pressure Fuel Line

- Tighten the fuel high pressure line union nut hand tight. Align so it is free of stress.

• Union nut: 18 Nm.

10 Intake Manifold Flaps

11 Gasket

• Always replace.

12 Intake Manifold

• Removing and installing, refer to --> [ Intake Manifold with Fuel Rail ] Intake Manifold With Fuel Rail.

13 Vacuum Actuator

• For the variable intake manifold.

• Checking, refer to --> [ Variable Intake Manifold, Checking ] Testing and Inspection.

14 Throttle Valve Control Module (J338)

• With the throttle drive (for Electronic Power Control (EPC)), throttle drive angle sensor 1 (for EPC) and throttle drive angle sensor 2 (for EPC).

• Removing and installing, refer to --> [ Throttle Valve Control Module ] Removal and Replacement.

• Cleaning, refer to --> [ Throttle Valve Control Module, Cleaning ] Procedures.

15 Bolts

• For the intake manifold.

• Pre-tighten to 3 Nm, and then tighten to 9 Nm.

16 Intake Manifold Runner Position Sensor (G336)

17 Fuel Pressure Sensor (G247), 22 Nm

• Coat the threads with clean engine oil.

• Checking, refer to --> [ Fuel Pressure Sensor, Checking ] Testing and Inspection.

• Removing and installing, refer to --> [ Fuel Pressure Sensor ] Service and Repair.

Fuel Injector Individual Parts





1. Combustion chamber sealing ring (Teflon sealing ring), always replace, the ring must not be greased or handled with any other lubricants when installing.

2. Intermediate ring

3. Fuel injector

4. Support ring, replacing

5. O-ring (replace, lubricate lightly with clean engine oil when installing)

6. Support element (the fuel rail wields force via the support element to hold the fuel injector tightly in the cylinder head)