Removal and installation of injectors (BMW 3 Series E46)

Fuel distribution line

New injectors are preserved. After 5 minutes of operation, they are released from preservation due to the fuel passing through. After removal from the engine, the injectors should not be stored for a long time due to the risk of corrosion.

Removal

1. Remove the air box, refer to Section Removal and installation the air intake box.

Models 316i, 318i

2. Remove the upper part of the intake manifold, refer to Section Removal and installation the intake manifold.

The fuel system is under pressure! Before unscrewing the hose connection, place a thick rag on it. Then carefully relieve the pressure in the hose. There is a risk of fire, do not smoke.

3. Clean the fuel lines. Then unscrew the supply and return lines.



4. Remove the 2 fuel distribution line mounting bolts.

Models 320i, 323i, 328i

5. Remove the top engine cover.



6. Loosen the mounting screws "1" and remove the plug strip upwards from the injectors.



7. Remove the mounting screws (arrows in the illustration) fuel rail. Note: The engine cover is not shown in the illustration.



8. Disconnect the oxygen sensor connector (2 arrows on the right).



9. Remove the injector connector strip and set it aside.

The fuel system is under pressure! Before unscrewing the hose connection, place a thick rag on it. Then carefully relieve the pressure in the hose. There is a risk of fire, do not smoke.

10. Clean the fuel lines with cold cleaner. Then, first disconnect the fuel supply line "1" (from the filter), and then the return hose "2" on the fuel distribution line, for which loosen the clamps. After unscrewing the clamps, they must be replaced with new ones.

Label the hoses to avoid confusion during assembly (refer to illustration).

11. On some models, the fuel hoses are secured with retaining clips. To remove, squeeze the clips with HAZET pliers #4501-1 or similar (arrows in the illustration).





12. Unscrew the mounting bolts (arrows in the illustration) fuel distribution line.

13. Disconnect the vacuum hose "1" at the fuel pressure regulator.

14. Pull the fuel rail complete with injectors up out of the cylinder head. The injectors are simply inserted and can be easily removed.

15. Remove the fuse and take out the injector.

Installation

Replace the deformed sealing rings "1", remembering the position of the rings "2". Lubricate the rings "1" with Vaseline or transmission oil before installation. Do not use engine oil, it has a negative effect on the rubber.

16. Insert the injectors into the fuel rail and secure with clamps.

17. Press the fuel rail with injectors evenly into the cylinder head.



18. Secure the fuel rail to the cylinder head.

19. Secure the fuel return and supply hoses to the fuel rail. Install new clamps and sealing rings, refer to the "Removal" subsection.

20. Install the injector connector strip and secure it.

21. Connect the vacuum hose to the fuel pressure regulator.

22. Models 316i, 318i: Install the upper part of the intake manifold, refer to Section Removal and installation the intake manifold.

23. Models 320i, 323i, 328i: Connect the oxygen sensor plug connections and secure them. Secure the engine cover.