Component Tests and General Diagnostics

Injector Spray Pattern:

Spray pattern quality effects all aspects of engine performance. Poor fuel injection performance can contribute to:

^ Hard starting and stalling when cold
^ Poor cold driveability
^ Rough idle
^ Poor acceleration
^ Combustion knock
^ Poor warm restart
^ Surging at cruise speed
^ Dieseling

INJECTOR TESTING

1. Remove the fuel injection rail/injector assembly.

Special Tool 13 6 205:

2. Remove the injectors and connect them to special tool (13 6 205 injection pipe).

Special Tool 13 6 206:

3. Connect special tool (13 6 206 wire harness) to the injectors.
4. Supply 42 psi air pressure to the injector pipe adapter.
5. Connect the wire harness to a 12 volt power source.

^ This will remove any residual fuel in the injectors.

6. Disconnect the power to the wire harness and remove the harness connectors from the injectors.
7. With the injectors connected to the injection pipe place in a suitable tank with water heated to 140 - 175°F.
8. While maintaining 42 psi air pressure check for air leaks.

^ Permissible leakage rate is 2 air bubbles per fuel injector within 15 seconds.
^ Note fuel injectors with greater air leakage rate.

9. Remove the fuel injectors from the water bath.
10. Remove the air pressure connection from the injection pipe, dry plug connections with compressed air and proceed with injector cleaning if not previously performed.

INJECTOR CLEANING

1. Connect special tool (wire harness 13 6 206) plugs to the injectors and connect harness leads to 12 volt power source.

BMW Injector Cleaner:

2. Suspend fuel injectors with injection pipe in BMW ultrasonic cleaner (special tool 13 6 200).
3. Clean and simultaneously supply current to the fuel injectors in accordance with the operating instructions of the cleaning machine.

NOTE: Do not apply air pressure while the injectors are in the cleaning machine.

^ Repeat the leakage test. Replace injectors that are not within specification.


ALTERNATE CLEANING METHOD

There are various aftermarket fuel injection cleaning systems. Portable systems which enable repair facilities to clean the injectors on a running vehicle are acceptable, however, manufacture specifications and instructions must be followed to prevent possible damage to BMW systems. If a cleaning method other than the above is used be sure to perform cleaning prior to removing the injectors for leakage test or spray pattern inspection.