For 1990-2009 cars

# DIESEL INJECTION NOZZLE CLEANING INFORMATION

AN ULTRASONIC NOZZLE CLEANER (J-29653) WAS PART OF THE 1982 MODEL ESSENTIAL TOOL PACKAGE. ITS PRINCIPAL USE IS FOR CLEANING 1980 - 1982 MODEL POPPET TYPE INJECTION NOZZLES. ULTRASONIC CLEANING IS EFFECTIVE IN REMOVING CARBON BUILDUP AND OTHER CONTAMINANTS. IT HAS BEEN DETERMINED THAT ULTRASONIC CLEANING WILL RESTORE VIRTUALLY ALL NOZZLES TO A LIKE NEW CONDITION. NOZZLES WHICH FAIL TO PASS RECOMMENDED TESTING PROCEDURES SHOULD BE CLEANED. THE ONLY EXCEPTIONS ARE THOSE NOZZLES WITH BROKEN COMPONENTS. NOZZLES HAVE A NUMBER OF PARTS THAT ARE SELECTED AND MATCHED AT THE FACTORY. THE NOZZLE COMPONENTS MUST NOT BE INTERMIXED. BECAUSE OF THE CLOSE TOLERENCES IN THE NOZZLE, EXTREME CAUTION MUST BE TAKEN WHEN ASSEMBLING THE NOZZLE. EVEN THE LINT OF A SHOP RAG MAY CAUSE THE NOZZLE NOT TO FUNCTION PROPERLY AFTER CLEANING. REFER TO SECTION 6C5 OF THE 1982 SERVICE MANUAL FOR FURTHER INFORMATION. SOME DED NOZZLES USED PRIOR TO 1981 MODELS MAY HAVE LOOSE EDGE FILTERS IN THE INLET FITTING. DIESEL EQUIPMENT DIVISION (DED) NOZZLES ARE IDENTIFIED WITH NOTCHES ON THE HEXAGON SURFACE. THESE FILTERS, WHEN LOOSE, TEND TO CAUSE EROSION WITHIN THE NOZZLE. A DED NOZZLE WITH A MISSING OR LOOSE EDGE FILTER SHOULD HAVE THE INLET FITTING REPLACED. INLET FITTING NO. 5233668 IS AVAILABLE FROM GMWWD FOR DED NOZZLES. IT IS ESSENTIAL THAT ALL NOZZLES BE TESTED ON A NOZZLE TESTER AFTER CLEANING TO FLUSH OUT THE CLEANING SOLUTION AND TO CHECK FOR PROPER OPERATION. FAILURE TO FLUSH OUT THE NOZZLE MAY RESULT IN NOZZLES THAT BECOME RUSTY AND UNUSABLE. 1978 AND 1979 MODELS AND CERTAIN EXPORT CARS OF LATER MODEL YEARS USE PENCIL TYPE NOZZLES THAT REQUIRE SPECIAL TOOLS TO ADJUST NEEDLE LIFT UPON REASSEMBLY. CLEANING AND ADJUSTING THESE NOZZLES SHOULD BE PERFORMED BY A ROOSA MASTER DEALER. WARRANTY CLAIMS FOR NOZZLE CLEANING AND TESTING WILL BE ACCEPTED ON ANY DIESEL EQUIPPED VEHICLE DURING THE NEW CAR LIMITED WARRANTY PERIOD 12-MONTHS/12,000 MILES USING THE APPLICABLE 1982 LABOR TIME GUIDE NOZZLE OPERATIONS. NOZZLES THAT ARE BROKEN OR FAIL TO PERFORM PROPERLY AFTER CLEANING WILL BE COVERED UNDER THE TERMS OF THE EMISSION WARRANTY.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.