pressure. Observe   nozzle   tip   for   fuel   leakage.   If nozzle  does  not  leak,  the  nozzle  valve  is  seating properly  in  the  valve  body.  If  drops  of  fuel  collect  at a   pressure   of   approximately   200   psi,   or   less,   below popping   pressure,   the   nozzle   valve   is   not   seating properly.   In   this   case,   the   valve   body   and   valve must  be  removed  for  cleaning  and  inspection. d.   If   the   nozzle   proved   satisfactory   when   subjected to  the  leakage  test  above,  operate  handle  at  a  speed of   approximately   100   strokes   per   minute   and   observe nozzle  spray  pattern. e.  The  nozzle  tip  has  four  equally  spaced  holes, 90   degrees   apart. Size  and  spacing  of  these  holes determine  the  spray  pattern.  If  fuel  is  discharged evenly  through  all  four  holes  at  specified  popping pressure,   the   spray   pattern   is   considered   satisfact- ory.   However,   if   fuel   is   not   discharged   evenly from  all  four  holes,  a  plugged  hole(s)  is  indicated, in  which  case,  the  nozzle  must  be  removed  and cleaned   using   a   proper   size   cleaning   wire. f.  Install  nozzle  holder  cap  nut  and  tighten  it  to 60  to  75  foot-pounds  torque. 14-41.  Nozzle  Holder  Assembly  Installation. Install   the   nozzle   holder   assembly.   Refer   to   opera. tor   and   Organizational   Maintenance   Manual. Section  VIII.  FUEL  INJECTION  PUMP  AND  RELATED  PARTS 14-42.    General. a.   The   fuel   injection   pump   is   a   single   cylinder, opposed   plunger,   inlet   metering,   distributor   type. The   plungers   are   operated   by   an   internal   cam   ring. The  purpose  of  the  pump  is  to  accurately  deliver metered   quantities   of   fuel   under   high   pressure   to   the nozzle   holder   assemblies   through   which   the   fuel   is introduced   into   the   engine   combustion   chambers,   at a  definite  timing  in  relation  to  the  engine  firing  cycle, and   within   the   required   injection   period. b.   On   Class   1,   Precise   Sets,   the   fuel   injection pump   is   controlled   by   the   hydraulic   actuator.   The hydraulic   actuator   operates   on   the   shut   down   lever to  automatically  control  fuel  flow  through  the  fuel injection  pump,  dependent  upon  load  conditions,  and thus   controls   engine   speed   and   response   to   load changes. c.   On   Class   2,   Utility   Sets,   this   fuel   injection pump   is   manually   controlled   from   the   control   located at   the   rear   of   the   set.   The   manual   control   is   con- nected  to  the  throttle  through  a  cable  and  sleeve assembly. d.   The   fuel   injection   pump   also   has   an   integral back-up   governor   of   the   mechanical   centrifugal (flyweight)  type. This   governor   is   driven   directly   off the  pump  drive  shaft  without  gearing. e.   The   transfer   or   supply   pump,   in   the   opposite end–of  the  rotor  from  the  pumping  cylinder,  is  a positive  displacement  vane  type  enclosed  by  the  end plate.   The   pump   is   self-lubricated   by   the   fuel supply. f.  Fuel  shut-off  is  accomplished  electrically  by  a solenoid   mechanism   within   the   fuel   pump.   When energized,   the   solenoid   opens   the   metering   valve   to permit  fuel  flow  to  the  engine. g.  An  external  adjustment  knurled  screw  at  the  rear of  the  pump  housing  provides  precise  control  of  gover- nor   sensitivity   by   decreasing   or   increasing   the effective   length   of   the   governor   control   spring. Turning   the   adjustment   screw   inward   shortens   the control   spring,   making   it   less   sensitive   and   increasing 14-30 speed   droop. Turning  the  screw  outward  has  the opposite    effect. Regulation  of  2-3  percent  can  be easily  attained  and  adjustment  can  be  made  while  the engine   is   operating. 14-43.   Fuel   Injection   Pump   Removal   and   Disassembly. a. Symptoms  and  Isolation  of  Malfunction.   A malfunction  of  the  fuel  injection  pump  is  usually  indi- cated  by  loss  of  engine  speed  and  power,  erratic engine   speed,   failure   of   engine   to   start   (when   electric starter   is   working   correctly),   or   sudden   engine   shut- down  when  there  is  no  fault  indication  such  as  low  fuel, high   coolant   temperature,   or   low   oil   pressure.   To isolate  the  malfunction  to  the  fuel  injection  pump, proceed   as   follows: (1)  Check  fuel  lines  and  fuel  injection  pump  for visible   signs   of   leakage. (2)  If  engine  cannot  be  started  or  if  it  has  shut down  suddenly,  loosen  the  fuel  input  line  to  the  fuel injection   pump. If  a  full  line  of  fuel  is  available,  it may  be  an  indication  that  the  pump  has  failed.  Tighten the  coupling. (3)  While  engine  is  cranking,  loosen  the  input to  one  of  the  fuel  injectors.  If  there  is  no  evidence  of available   fuel,   the   fuel   injector   pump   has   failed. (4)  Remove  timing  cover  on  pump  and  observe that  pump  rotates  when  engine  cranks. (5)  Check  for  24  Vdc  at  solenoid  terminals  on top  cover.  of  injection  pump. (6)   Check   solenoid   (para   14-46).   If   no   conti- nuity,   replace   solenoid. (7)  Refer  to  table  14-1  for  troubleshooting  the fuel   injection   pump. b.   Removal.   (See   figure   14-20.) (1)   Refer   to   the   Operator   and   Organizational Maintenance  Manual  and  drain  fuel  day  tank  and  dis- connect  fuel  line  to  pump.