Fuel - Injector Cleaning Procedure
86bmw10GROUP Fuel System
Bulletin Number 13 08 86 (1176) Page 1 of 6
Montvale, NJ May 1986 Technical Dept.
SUBJECT Fuel Injector Cleaning Procedure
MODELS: All L-Jetronic and Motronic Cars since 1982
Condition: Rough idle/poor driveability.
Cause: Carbon buildup on injectors.
Correction: Clean injectors with injector cleaner using the procedure Outlined in this Service Information Bulletin. The instructions on the cleaner tank are issued by Kent Moore for general automotive use. Some of them may not apply exactly to a BMW. Follow the instructions from this bulletin.
Procedure: WARNING
1) GASOLINE - FLAMMABLE - NO SMOKING
2) Contents under pressure
READ ALL INSTRUCTIONS IN THIS S.I. THOROUGHLY BEFORE PROCEEDING. OBSERVE ALL WARNINGS/CAUTIONS!
CAUTION
Inline valve must be closed when connecting and disconnecting discharge hose from the vehicle fuel rail access fitting. Cleaning mixture is under pressure and fuel rail is under pressure. Do not store mixture in tank or hose. For storage, always empty mixture from tank and hose and dispose of properly.
Do not tamper with or replace components other than those supplied by Kent-Moore. Do not position hose or tank next to exhaust, high heat source or any moving parts. Have Class B fire extinguisher handy.
Never pressurize the tank beyond 35 PSI.
Always wear protective clothing, eye and face protection because of possible spraying (residual pressure) when you break the fuel line.
Always make sure that all fuel hose clamps are tightened before pressurizing.
NOTICE: To use this device the vehicle fuel system must hold pressure (fuel pressure regulator and fuel pump check valve must be functioning properly). If it does not hold pressure, repair as required before proceeding.
A. Fuel Injector Cleaning
1. Depressurize cleaner tank via the pressure relief pull ring.
2. Remove the pump and cap assembly from the cleaner tank.
3. Attach access fitting assembly of injector cleaner to the rear part of the car fuel pressure line (as illustrated in Attachment 1) at the fuel rail inlet.
4. Connect the discharge hose of the cleaner to the access fitting you installed in Step 3 and open the inline valve one turn.
5. Remove fuel pump relay and connect the remote battery push button (BMW special tool P/N 88 88 6 613 050) to pins 30 and 87 on all cars except 318i (and to pins 30 and 87b on 318i) of the fuel pump relay socket. Press the red button and manually run the car fuel pump.
CAUTION: Do not jump relay with wire as a spark may occur!
6. Hold push button valve open draining one and a half quarts of fuel from the car into cleaner tank. NOTE: top of indicator tube inside cleaner tank is 1-1/2 quarts.
7. Stop car electric fuel pump and remove the remote battery push button from the fuel pump relay socket.
8. Add 3 ounces ONLY of Kent-Moore fuel injector cleaner to cleaner tank. Use only BMW approved injector cleaning solvent. Order direct from BMW Parts Department.
Notice: Do not exceed 3 ounces of injector cleaner in 1-1/2 quarts of gasoline and do not add cleaner directly into vehicle fuel tank, as severe damage to the fuel system components may result.
9. Install pump and cap assembly into cleaner tank turning clockwise. Pump until pressure gauge indicates the following reading for each model. DO NOT EXCEED THE PRESSURE DESCRIBED BELOW AS THIS COULD FORCE SOME OF THE CLEANING FLUID PAST THE PRESSURE REGULATOR AND INTO THE CAR FUEL TANK THROUGH THE RETURN LINE. 318i - 30 PSI (2 bar) 325e/528e - 25 PSI (1.7 bar) 533i/633CSi/733i - 25 PSI (1.7 bar) 535i/635CSi/735i - 30 PSI (2 bar)
10. For 318i reinstall the fuel pump relay and remove fuse 11 from the fusebox (the injectors of 318i get power from fuel pump relay pin 87). For all other vehicles do not reinstall the fuel pump relay.
11. With the vehicle electric fuel pump thus disabled, start engine and run at 3000 RPM for 15 minutes or until engine starts to stumble steadily. For additional cooling, use an external fan. During this time if you notice a pressure drop on the cleaner gauge of 1.5 psi (0.1 bar) or more, bring the pressure back up by using the hand pump.
Note: When pump handle is locked, turn handle no more than 90~ counterclockwise for repressurizing. If pump handle is already in pump position, don't turn it further because you might relieve the pressure through the cap. After 15 minutes of running, or if engine runs out of cleaning solution slightly sooner and starts to stumble steadily, when you hear the steady miss, decrease the RPM to idle and shut ignition off.
12. Relieve the pressure from the cleaner through the relief valve and depressurize discharge hose and fuel rail (with inline valve still open) by pressing the push button valve until gauge shows no pressure.
13. Close inline valve on discharge hose and remove access fitting assembly immediately, to prevent repressurizing of the fuel rail and hose due to warm gasoline. Whenever you disconnect a hose from the inlet pipe of the fuel rail, wear eye protection and wrap a shop rag around the inlet of the fuel rail to prevent gasoline spray. Remember the fuel rail is pressurized even with the engine off!
14. Reconnect car fuel line to original location.
15. Reinstall fuse 11 into the fusebox for 318i, for all other vehicles reinstall the vehicle fuel pump relay and immediately run the engine for at least 5 minutes at 2000 RPM to flush the cleaner from the fuel rail and the injectors.
16. Check fuel hose connections for leakage.
C. STORAGE INSTRUCTIONS
^ Depressurize tank via the pressure relief valve pull ring.
^ Drain any remaining solution from tank and hose; dispose of solution properly; do not add to vehicle fuel tank.
^ Partially unscrew pump to function as vent.
D. OPERATING HINTS
^ Do not use more than 1-1/2 quarts of solution in tank as this will decrease air volume and tank pressure will drop too quickly during cleaning procedure.
^ Use pressure gauge on discharge hose to determine if fuel pump has been disabled and to verify if fuel system is holding pressure.
^ Keep inside of cleaner tank clean.
Warranty
Status: Reimbursement for injector cleaning (on a one time only basis), as outlined in this bulletin will be provided through normal Warranty claim processing with no limitation on age or mileage of the affected vehicle, only when this repair is performed in conjunction with and within the limits described in the BMW
"86 ENGINE CAMPAIGN", and the repair is performed on or before May 31, 1987.
The following special defect code and labor operation number must be used:
Defect Code: 00 00 11 71 00
Labor Operation Nr.: 00 50 584
Labor Allowance: 3 FRU
Sublet (for cleaning fluid):
Value: $1.00
Code: 4