4-40. 4-41. 4-42. 4-43. 4-44. Question 4-40 is to be judged True or False. The  pump-injection  system  that  combines  a high-pressure  pump  and  fuel  injection nozzle  into  one  unit  is  called  a  unit injector. Which  of  the  following  injection  systems uses  a  metering  device  that  delivers  the appropriate  amount  of  fuel  to  each injector? 1. Atlas 2. Cooper-Bessemer 3. Bosch 4. Cummins Which  of  the  following  factor(s) control(s)  the  amount  of  fuel  that  is injected  by  the  cam-operated  injector valves  of  the  basic  common-rail  injection system? 1. The  length  of  time  the  nozzle  stays open 2. The pressure held by the high-pressure  pump  in  the  common rail 3. The  action  of  the  individual  valves mounted  on  the  side  of  the  engine 4. The  length  of  time  the  nozzle  remains open and by the pressure held by the high-pressure  pump  in  the  common rail Question 4-43 is to be judged True or False. Most  diesel  injection  equipment  operating problems  are  resolved  when  clean  fuel  is used. Which  of  the  following  is  the  best  method to  determine  whether  the  bushing  assembly of  a  unit  injector  has  been  damaged? 1. Place the injector in a test stand and  test  the  bushing  assembly 2. Install the injector in a test engine,  operate  the  engine,  and check  for  low  firing  pressure 3. Disassemble  the  injector,  clean  it, and  inspect  each  part  of  the  bushing assembly 4. Install the injector in a test engine, operate  the  engine,  and check  for  low  exhaust  temperature 4-45. Which  of  the  following  operations  is affected  by  irregularities  in  the  surface and  helix  edge  of  a  plunger? 1. Pumping 2. Metering 3. Combustion 4. Firing 4-46. If the lapped surfaces of a plunger and barrel  assembly  are  exposed  to atmospheric  dust,  the  surfaces  will 1. erode 2. rust 3. score 4. bind Questions  4-47  and  4-48  are  to  be  judged True or False. 4-47. Some  fuel  oil  systems  have  additional safety  filters  or  screens  located  between the  fuel  transfer  pump  and  the  fuel distributor. 4-48. The  absorbent  qualities  of  cotton  waste make  it  an  excellent  drying  agent  for fuel  injector  parts. 4-49. Lapped  surfaces  should  be  handled  only after  they  have  been 1. allowed  to  dry  at  room  temperature 2. immersed  in  clean  diesel  oil 3. washed  in  distilled  water 4. dried  by  heat  for  several  minutes 4-50. External  leakage  of  diesel  fuel  from pumps  and  injectors  is  probably  caused  by which  of  the  following  conditions? 1. Loose  connections,  scored  plungers, or  cracked  housings 2. Scored  plungers,    improper  assembly, or  broken  springs 3. Eroded  bushing  ports,  loose connections, or broken springs 4. Improper  assembly,  loose  connections, or  cracked  housings 4-51. On  some  fuel  injection  equipment,  mild roughness  and  discoloration  of  the sealing  surfaces  may  be  removed  by which  of  the  following  methods? 1. Lapping 2. Scrapping 3. Grinding 4. Honing 26