Fuel Injector: Service and Repair

13 53 310 Removing And Installing/replacing An Injector (N55)







Special tools required:
- 00 9 170
- 13 0 191
- 13 0 270
- 13 0 281
- 13 0 282
- 13 0 283







WARNING:
Observe warning on cylinder head cover.
Disconnect negative battery terminal (risk of fire due to short circuit on removal).
Electric fuel pump starts up automatically when door is opened.
Carry out installation work on fuel system only with coolant temperature below 40 °C.







WARNING:
Wear full face guard and protective gloves.
Fuel can emerge spontaneously at high speed from the fuel injectors.
To reduce the fuel pressure, place rag over fuel injector and carefully tap against the fuel injector with a spanner.
There is a danger of injury if the fuel pressure is not reduced.







IMPORTANT:
Injectors may be pulled out with a maximum tensile force of 2000 N and only turned with 6 Nm (torsional motion). If these values are exceeded, the injectors must be replaced.







IMPORTANT:
When assembling, it is essential to adhere to screwing sequences and tightening torques.
Failure to comply with this requirement may result in leaks.







IMPORTANT:
Adhere to conditions of absolute cleanliness when carrying out repair work on the high-pressure fuel system.
Introduced dirt contamination can cause malfunctions in the system.
- Do not allow any dirt particles or foreign bodies to get into the system.
- Remove all traces of dirt contamination before removing pipes or individual components.
- Use only fluff-free cloths.
- Seal all fuel system openings with protective caps or plugs.
- High pressure lines may be rescrewed a maximum of 10 times.







IMPORTANT:
Injectors are not waterproof.
Carry out an engine wash only with ignition coil cover fitted.

Necessary preliminary work:
- Remove ignition coil of corresponding cylinder.







NOTE:
- Ignition coils must not become coated with fuel.
The resistance of the silicone material is reduced significantly by contact with fuel, which may cause the ignition coil to fail! It is therefore essential to protect the spark plug slot against ingress of fuel with a cloth.
- Before installing ignition coils, clean spark plug slots with compressed air.
- Make sure the spark plug slot is absolutely clean.
- Remove pressure lines of corresponding cylinder.







NOTE:
The following description applies to all injectors.

Slacken nut (1).
Tightening torque 12 90 5AZ.
Remove the earth cable.
Unlock connectors (2) on injectors and disconnect.
Release screw plug (3) and remove.







Release screws (1).
Remove clamping plate (2) and retainer bridge (3).
Remove EMC panel (4).







Release screw (1).
Feed out hold-down device (2) and remove.
Pull injectors (3) upwards out of the cylinder head and remove.

NOTE:
If several injectors are removed, ensure that each injector is reinstalled in its original installation location (cylinder).
Mark injectors.







Procedure in event of stuck injector:
To remove jammed injectors, use special tool 13 0 270.
Before using the special tool, lightly oil the withdrawing thread.

IMPORTANT:
The withdrawing thread (1) is a left-hand thread.
Threaded bush (2) is a right-hand thread.







Apply special tool (1) 13 0 270 to injector slot.
Turn the screws (2) by a number of threads on the injector slot. Screw threaded bushes (3) onto the injectors and tighten. If necessary, screw the withdrawing thread (4) up or down.3
Tighten down screws (2).
Tightening torque 13 53 13AZ.







IMPORTANT:
Set the torque wrench (1) to 5 Nm. Together with special tool 13 0 270, this corresponds to a tensile force of maximum 2000 N. If the torque wrench makes a cracking sound on pulling out the injector, the injector has to be replaced.

Apply the torque wrench (1) and special tool (2) 00 9 170 at the square end (3) of the special tool 13 0 270.
Turn the torque wrench (1) clockwise until the injector has been withdrawn.
Make sure that the retaining pin (4) is not contacting the cylinder head cover; press retaining pin back if necessary. Risk of damage.







After removing, fit protective caps (1 and 2) to injector tip and fuel line connection.

Installation note:
When installing a new injector:
- Replace decoupling element (3).







Installation note:
When reusing fuel injector:
- Replace decoupling element (1).
- Replace PTFE sealing ring (2).
A PTFE sealing ring which has been heated once by engine operation must be replaced before the fuel injector is reinstalled.







Replacing PTFE sealing ring:
Before replacing PTFE sealing ring (1), make sure hands and work surface are clean and free of oil.
Avoid mechanical contact with injector tip (2).







Remove PTFE sealing ring (2) with special tool (3) 13 0 191 from injector (1).
Use a fluff-free cloth only to remove combustion residues from cylindrical part of injector tip (do not use ultrasound or other tools/agents).
Do not clean injector tip.







Slide new PTFE sealing ring (1) onto mounting taper (2) 13 0 283.







Mount the PTFE sealing ring (1) with mounting taper (2) 13 0 283 on the injector tip (3).

NOTE:
- Do not use fingernails to slide PTFE sealing ring on.
- Do not use any lubricating agents.
- The sealing ring is expanded when slid on.







Using special tool (1) 13 0 281, slide the PTFE sealing ring into the groove (3) on the injector.







To get the expanded PTFE sealing ring to its installation dimension, the special tool (1) 13 0 282 must be pushed onto the injector (2) as far as it will go.
Do not use any lubricating agents.







NOTE:
Pull the mounting tip (1) off the special tool 13 0 282 towards the rear to loosen the mounting taper (2) 13 0 281.







Installing injector:
Installation of injector is described separately from removal.







Before installing injector in engines that have been run:

IMPORTANT:
Injectors may only be turned with 6 Nm..
If this value is exceeded, the injector must be replaced.

- Check injector bore for dirt contamination.
Clean only dirty injector bores.

IMPORTANT - do not damage injector.

- Clean injector bore: To do so, preferably slide injector without decoupling element (1) but with new PTFE sealing ring (2) in and out of injector bores several times.
The PTFE sealing ring must then be replaced.
- Clean contact surfaces of decoupling elements (1) in cylinder head.
- Replace decoupling element (1).







IMPORTANT:
Injector adjustment.


An injector adjustment must be carried out if an injector is replaced or changed on the cylinder side.
Injector adjustment is carried out with the aid of a so-called adjustment value.
Depending on the version, the adjustment value (three digits) is stamped on the injector body.
The adjustment value must be read off before installation.







Enter the adjustment value according to the installation location (cylinder) of the injector.
If injector adjustment is not carried out, the engine may run roughly or fail to start.
Description of injector adjustment at end of instructions.







Installing injector:
Apply special tool (1) 13 0 270 to injector slot. Turn the screws (2) by a number of threads on the injector slot. Screw threaded bushes (3) onto the injectors and tighten. If necessary, screw the withdrawing thread (4) up or down.
Tighten down screws (2).
Tightening torque 13 53 13AZ.







IMPORTANT:
Set the torque wrench (1) to 2 Nm.

Apply the torque wrench (1) and special tool (2) 00 9 170 at the square end (3) of the special tool 13 0 270.
Turn the torque wrench (1) anticlockwise until 2 Nm is reached.
Make sure that the retaining pin (4) is not contacting the cylinder head cover; press retaining pin back if necessary. Risk of damage.







Fit the injectors (3).
Install hold-down device (2).

IMPORTANT:
Tighten bolt (1) hand-tight only so that hold-down device (2) is slack and if necessary injector can still be turned.







Align injectors.

IMPORTANT:
Injectors may only be turned with 6 Nm.
If this value is exceeded, the injector must be replaced.

Fit the EMC panel (1).
Insert the retainer bridge (2).







Insert the clamping plate (1). Make sure it is in the right installation position (see illustration).
Insert screws (2) and hand-tighten only.







Fit the pressure lines on the injectors and rail. In so doing, only hand-tighten nuts (1) and (2).

Installation note:
Reinstall line damper (3).







Tighten the hold-down screw (1) through the EMC panel.
Tightening torque 13 53 6AZ.







Tighten the screws (1) of the EMC panel evenly.
Tightening torque 13 53 11AZ.







Tighten the screw plug (1) on the EMC panel.
Tightening torque 13 53 12AZ.







Tighten the pressure lines on the injectors (1).
Tightening torque 13 53 9AZ.
Then tighten down the pressure line (2) on rail.
Tightening torque 13 53 9AZ.

Installation note:
Reinstall line damper (3).







Carrying out injector adjustment:
Depending on the version, the adjustment value (three digits) is stamped on the injector body.







- Connect BMW diagnosis system
- Identify car
- Select "Function selection"
- Select "Service functions"
- Select "Engine electronics"
- Select "Adjustment function"
- Select "Adjust injectors"
- Select "Test plan"
- For each replaced injector, the adjustment value must be entered according to the installation location (cylinder).







Clean spark plug slot.
Assemble engine.
Check fuel system for leak tightness.
Check function of Digital Engine Electronics.

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