TM 5-3895-382-24 NOTICE Do  not  use  dirty  test  fluids  when  you  test  fuel  injection nozzles.    Also,  do  not  test  fuel  injection  nozzles  unless you have the correct service tools.  The use of dirty test fluids and the use of incorrect service tools will result in damage to fuel injection nozzles. 1. Refer   to   Illustration   52   in   order   to   connect   the   fuel injector nozzle (2) to the tooling. The spray from the fuel injector nozzle must be directed into the  1U-8857  Extension  (4)  and  the  8S-2270  Fuel Collector (6). Use  clean   6V-6068   Calibration   Fluid   when   the   fuel injector   nozzles   are   tested.      The   calibration   fluid   is equivalent to SAE J-967 (ISO 4113) oil. 2. Close   the   gauge   protector   valve.      Close   the   shutoff valve.  Open the pump isolator valve.  In order to flush the fuel injector nozzle, operate the nozzle tester for 10 to   15   strokes   by   using   a   rate   of   approximately   60 strokes per minute. 3. Open  the  gauge  protector  valve.    Slowly  increase  the pressure until the valve in the fuel injector nozzle opens. Note   the   highest   pressure   Indication   on   the   gauge before  the  pointer  decreases  to  0  kPa  (0  psi).    This highest  pressure  indication  is  the  opening  pressure  of the   fuel   injector   nozzle.      The   opening   pressure   is defined  when  the  valve  needle  (16)  is  lifted  from  the valve seat. Refer   to   the   table   in   Specifications,   "Fuel   Injection Nozzles"  for  correct  pressure  settings.    If  the  opening pressure is not within the range of the setting which is listed  in  the  table,  the  opening  pressure  of  the  fuel injector nozzle must be adjusted. 4. Loosen  the  cap  nut  (9).    Turn  the  pressure  adjusting screw (11) clockwise in order to increase the pressure. Turn the pressure adjusting screw counterclockwise in order to decrease the pressure. 5. Tighten  the  cap  nut  (9).    Check  the  opening  pressure again  on  the  nozzle  tester.    If  the  pressure  is  correct, remove the fuel injector nozzle from the nozzle tester. NOTE:    Before  the  fuel  injector  nozzle  is  removed  from the tester, be sure that the gauge protector valve is   closed   in   order   to   prevent   damage   to   the pressure gauge. Back Leakage Test 1. Refer   to   Illustration   52   in   order   to   connect   the   fuel injector nozzle (2) to the tooling. Position the fuel injector nozzle so that the fuel spray is directed   into   the    1U-8857    Extension    (4)    and    the 8S-2270 Fuel Collector (6). 2. Pump  the  pressure  to  about  1030  kPa  (150  psi)  less than  the  opening  pressure  of  the  fuel  injector  nozzle. Refer to Specifications, "Fuel Injection Nozzles" for the correct  setting  of  the  opening  pressure.    Release  the handle.  Note the time that is required for the pressure to decrease to approximately 0 kPa (0 psi).  If the fuel injector nozzle is not defective, the time will not be less than 5 seconds or more than 45 seconds. 3. When the test in Step 2 is done, look for any leakage from the pressure faces of the holder and the retaining nut of the fuel injector nozzle.  If leaks are visible, make sure  that  the  components  are  tightened  to  the  correct torque.      If   leakage   continues   to   occur,   unscrew   the retaining   nut   from   the   body.      Inspect   the   threaded surfaces   for   foreign   particles   and   damage.      If   the threaded surfaces are clean and the threaded surfaces are  undamaged,  test  the  fuel  injector  nozzle  again  by using Steps 1 and 2. 4. If the pressure decreases to 0 kPa (0 psi) in less than 5 seconds, too much fuel leaks around the valve needle. The  valve  needle  or  the  fuel  injector  nozzle  must  be replaced in order to correct the problem. Fuel Injector Nozzle And Seat Test 1. Refer   to   Illustration   52   in   order   to   connect   the   fuel injector nozzle (2) to the tooling. Position the fuel injector nozzle so that the fuel spray is directed   into   the    1U-8857    Extension    (4)    and    the 8S-2270 Fuel Collector (6). 2. Pump the pressure of the nozzle tester to approximately 1030 kPa (150 psi) below the opening pressure of the fuel injector nozzle.  A drop of fuel should not form on the tip of the fuel injector nozzle in order for a sufficient quantity to drip from the tip for at least ten seconds.  A light dampness is acceptable.  If the results of the tests are   not   acceptable,   clean   the   fuel   injector   nozzle. Replace  the  fuel  injector  nozzle  if  fuel  leakage  occurs after cleaning the fuel injector nozzle. 6-64