CUSTOMERS AFFECTED: DEUTZ, HATZ, IVECO, LOMBARDINI, RUGGERINI, VM MOTORI, VOLKSWAGEN, YTO

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Morgan Fowler
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523 dated April 30, 1998 SUBJECT: RATE SHAPING NOZZLE (RSN ) FEATURE FOR 17MM, 17/21MM AND 21MM INJECTORS CUSTOMERS AFFECTED: DEUTZ, HATZ, IVECO, LOMBARDINI, RUGGERINI, VM MOTORI, VOLKSWAGEN, YTO The

By throttling the fuel flow before the needle valve reaches maximum lift, the RSN feature can help reduce exhaust emissions, lower engine idle noise, and improve fuel economy.

1 SERVICE BULLETIN DATE: March 18, 2009 NO: 523R1 SUPERSEDES: S.B. 523 dated April 30, 1998 SUBJECT: RATE SHAPING NOZZLE (RSN ) FEATURE FOR 17MM, 17/21MM AND 21MM INJECTORS CUSTOMERS AFFECTED: DEUTZ, HATZ, IVECO, LOMBARDINI, RUGGERINI, VM MOTORI, VOLKSWAGEN, YTO The Stanadyne rate shaping nozzle offers a simple, compact method of controlling fuel flow rates during the early stages of the injection cycle. By throttling the fuel flow before the needle valve reaches maximum lift, the RSN feature can help reduce exhaust emissions, lower engine idle noise, and improve fuel economy. In addition, the RSN design uses a single spring, eliminating the need for costlier two spring injectors. A cutaway view of a typical 17/21mm injector with a rate shaping nozzle is shown below in Figure 1. Holder Body Lower Guide Rate Shaping/Cross Sectional Orifice Area Body Single Low Spring Retaining Nut (17/21mm) Rate Shaping Figure 1 Spray Orifice Needle The principles of RSN operation can be understood by studying Figures 2 and 3. With the needle valve fully seated (Figure 2a), fuel pressure increases until spring pressure is overcome and the valve lifts from its seat. As the valve lifts, the flow rate is controlled through the cross sectional orifice (an annulus created between Stanadyne Corporation 92 Deerfield Road, Windsor, CT 06095, U.S.A. Tel: (860) ; Fax: (860) ;

2b). With the valve at its maximum lift, the cross sectional orifice is wide open and full fuel flow through the spray

No Fuel Flow Rate Shaping Full Fuel Flow Cross Sectional Orifice (Annulus) Maximum Lift Closed Throttled Open Covers

Other nozzle sac types are also used with the RSN feature.

2 - 2 - S.B. 523R1 the outside diameter of the needle valve and the inside diameter of the nozzle body, as shown in Figures 1, and 2b). With the valve at its maximum lift, the cross sectional orifice is wide open and full fuel flow through the spray orifices is achieved (Figure 2c). No Fuel Flow Rate Shaping Full Fuel Flow Cross Sectional Orifice (Annulus) Maximum Lift Closed Throttled Open Covers Orifice (VCO) Sac Type* Figure 2a Figure 2b Figure 2c VCO Sac type shown for illustration purposes only. Other nozzle sac types are also used with the RSN feature. Closed (Figure 2a) Rate Shaping Area (Figure 2b) Maximum Flow Area (Figure 2c) Maximum Lift Flow Rate Standard Rate Shaping Figure 3 Needle Lift Injector Service Servicing an injector assembly equipped with a rate shaping nozzle consists of cleaning, component replacement, setting, and testing according to the procedures outlined herein, the individual service specification, and the Conventional

- 3 - S.B. 523R1 Injector Service Manual.

Kit, P/N 29167) Figure 4 Service assemblies with the rate shaping feature can only be cleaned or replaced as a complete assembly.

3 - 3 - S.B. 523R1 Injector Service Manual. The injector clamping fixture from kit P/N (Reference & 99920), fitted with the appropriate injector adapter plate should be used when disassembling and re-assembling injectors to avoid damaging the dowel pins (Figure 4). Holder Body Spring Seat Pressure Adjusting Spring Dowel Pins Retaining Nut Pressure Adjusting Shim Adapter Plate Rate Shaping Injector Adapter Plate Injector Clamping Fixture (From Injector Service Kit, P/N 29167) Figure 4 Service assemblies with the rate shaping feature can only be cleaned or replaced as a complete assembly. IMPORTANT: Because the injector flow characteristics are dependent on extremely close valve to body clearances and valve lift tolerances, grinding or lapping of a rate shaping nozzle valve or nozzle body are not permitted. The orifice holes and cleaning wires can be very small in diameter. Use a pin-vise (P/N 16483) and exercise extreme care when cleaning nozzle assemblies to prevent scoring or damage of the orifice holes. Never use a motorized and/or steel brush for cleaning nozzle assemblies as orifice hole deformation may result. Clean the nozzle needle valve with a felt pad. A clean, oiled and proper fitting valve will slide to the bottom of the nozzle body under its own weight when retracted 1/3 of its height and released. Injector Testing Injector assembly testing is performed using a standard hand-operated injector tester to check nozzle opening pressure (NOP), spray pattern, and seat leakage.

4 - 4 - S.B. 523R1 Before testing, the injector assembly should be flushed using a fast handle stroke (approximately 2 seconds of stroke duration). This will purge air from system and seat the injectors internal components. IMPORTANT: The traditional nozzle chatter (Ref ) will either be less pronounced or non-existent when testing injector assemblies equipped with rate shaping nozzles. The lack of chatter is an acceptable characteristic for the RSN design and should not be used as a basis to determine injector/nozzle condition. Opening Pressure 1. The nozzle opening pressure is tested with a slow handle stroke (approximately 6-10 seconds of stroke duration). Record the pressure at which the nozzle valve opens and fluid flows through the nozzle spray orifices. IMPORTANT: When performing NOP testing, injectors with RSN nozzles may exhibit the following characteristics that are considered to be normal: Hosing or a non-atomized spray plume. Spray plume (flow) may not be present at all orifices. chatter is minimal or non-existent. 2. If the opening pressure is incorrect, pressure adjusting shims (Ref. Figure 4) may be added or subtracted to achieve the desired pressure. Typically, each.025 mm (.001 inch) of shim represents approximately 3.8 bar (55 psi). Whenever possible, a single shim is preferred but a maximum of two shims may be used. Seat Tightness 1. Using a slow handle stroke (6-10 seconds), bring the pressure to the nozzle opening pressure then allow pressure to drop at least 20.7 bar (300 psi) below the actual opening pressure. 2. Dry the nozzle tip with a clean lint-free cloth and maintain the pressure for 5 seconds. Inspect the nozzle tip for wetness or leakage. Fluid drop formation is not acceptable, but wetness on a used nozzle is permissible. Droplet formation indicates the necessity for complete nozzle assembly replacement. NOTE: Due to various fuel return configurations, some injectors may need to be slightly inverted (nozzle end up) to ensure that return fuel does not flow down onto the nozzle assembly during this test. Fluid Leakage External fluid leakage, other than from the fuel return port, is not acceptable and must be repaired. Internal leakage can be checked as follows:

5 - 5 - S.B. 523R1 1. Using a slow handle stroke (6-10 seconds), raise the pressure to bar (1700 psi). Release the handle and allow the pressure to fall. 2. Record the time it takes for the pressure to drop from bar (1500 psi) to 69.0 bar (1000 psi). If the pressure decays in less than 10 seconds, the nozzle assembly will require replacement. Spray Pattern 1. Using a fast handle stroke (2 seconds), check for fuel flow (spray plume) from each spray orifice hole. Poor plume atomization is acceptable, but non-existent flow thru an orifice hole may indicate the need for nozzle assembly service or replacement. IMPORTANT: Poor spray plume atomization (hosing) may be evident when checking spray pattern. This is considered normal for RSN featured injectors and can be more pronounced on nozzle assemblies that employ both the RSN feature and a VCO sac type. Beginning of Injection (BOI) Sensor This feature is no longer offered in current production. However, some engines were originally fitted with one injector equipped with a proximity type sensor. The sensor monitors the beginning of needle valve lift and supplies the Engine Control Unit (ECU) with the necessary injection timing feedback for precise timing control. The sensor can be tested for continuity: ohms of resistance at room temperature and ohms resistance at engine operating temperature. The sensor is non-serviceable except by complete nozzle holder body assembly replacement. To avoid sensor damage during injector service, prevent metallic debris from entering the spring chamber area of the nozzle holder body assembly and never direct compressed air into the nozzle holder body assembly passages. Warranty Stanadyne warrants all RSN equipped injector assemblies and nozzles against defects in material and workmanship in accordance with the Stanadyne Policies and Procedures Manual (99966) as outlined in Section 4.0. Refer to the Stanadyne service website for the latest warranty information. Technical Support Group Product Support Department Revision Date Changes 1 3/09 Remove specific injector/customer reference. Include additional service information and procedures.

Focus On Training Section: Unit 4

Focus On Training Section: Unit 4 All Pump Types Page 1 1. Title Page Be able to describe unit learning objectives: 2. Fuel System Be able to briefly note the components of a typical fuel injection system 3. Nozzle Location Know the difference