Question 1

Fuel injected per crank angle degree in a diesel fuel system is known as:

Accepted Answer

A)  injection rate 
B)  injection quantity 
C)  atomization rate 
D)  delivery rate 
A)  injection rate 
B)  injection quantity 
C)  atomization rate 
D)  delivery rate A

Question 2

Which of the following would indicate the lowest engine rpm?

Accepted Answer

A)  peak torque 
B)  high idle 
C)  engine lug 
D)  droop curve 
A)  peak torque 
B)  high idle 
C)  engine lug 
D)  droop curve C

Question 3

What state is atomized fuel in?

Accepted Answer

A)  vapor 
B)  aerated 
C)  gas 
D)  liquid 
A)  vapor 
B)  aerated 
C)  gas 
D)  liquid D

Question 4

In a current direct injected diesel engine governed at 2000 rpm, what droplet size range must the injection system produce?

Accepted Answer

A)  1 - 10 microns 
B)  10 - 100 microns 
C)  100 - 200 microns 
D)  200 - 500 microns 
A)  1 - 10 microns 
B)  10 - 100 microns 
C)  100 - 200 microns 
D)  200 - 500 microns

Question 5

Why does retarding injection timing tend to produce higher HC emissions?

Accepted Answer

A)  increases injection lag 
B)  reduces time available for combustion 
C)  increases ignition lag 
D)  increases combustion temperatures 
A)  increases injection lag 
B)  reduces time available for combustion 
C)  increases ignition lag 
D)  increases combustion temperatures

Question 6

An engine has a rated speed of 2000 rpm and has 40% torque rise. At what rpm would you expect to find peak torque?

Accepted Answer

A)  2000 rpm 
B)  800 rpm 
C)  1200 rpm 
D)  2800 rpm 
A)  2000 rpm 
B)  800 rpm 
C)  1200 rpm 
D)  2800 rpm

Question 7

When a crankshaft throw is positioned at exactly TDC, how much mechanical leverage can it apply to the crankshaft?

Accepted Answer

A)  none 
B)  minimum 
C)  50% of maximum 
D)  maximum 
A)  none 
B)  minimum 
C)  50% of maximum 
D)  maximum

Question 8

When a 4-stroke cycle engine rotates at 2000 rpm, how many power strokes occur in any one of its cylinders per second?

Accepted Answer

A)  500 
B)  100 
C)  17 
D)  8 
A)  500 
B)  100 
C)  17 
D)  8

Question 9

When fuel condenses on the piston crown during injection, which of the following can result?

Accepted Answer

A)  pitting 
B)  pre-ignition 
C)  pinging 
D)  detonation 
A)  pitting 
B)  pre-ignition 
C)  pinging 
D)  detonation

Question 10

Which of the following governing classifications would allow the accelerator pedal in a truck diesel engine to respond like that in an automobile?

Accepted Answer

A)  limiting speed 
B)  variable speed 
C)  isochronous 
D)  all-speed governor 
A)  limiting speed 
B)  variable speed 
C)  isochronous 
D)  all-speed governor

Question 11

When a hydromechanical governor throttle is snapped (to full fuel request) under no-load, engine rpm temporarily exceeds the high idle speed. What is the term used to describe this condition?

Accepted Answer

A)  hunting 
B)  top end limit 
C)  deadband 
D)  overrun 
A)  hunting 
B)  top end limit 
C)  deadband 
D)  overrun

Question 12

What is the reason for advancing injection timing as engine speed increases?

Accepted Answer

A)  real time available for combustion decreases 
B)  real time available for combustion increases 
C)  less air in engine cylinder 
D)  more air in engine cylinder 
A)  real time available for combustion decreases 
B)  real time available for combustion increases 
C)  less air in engine cylinder 
D)  more air in engine cylinder

Question 13

When a diesel engine is said to be hydromechanically managed, which of the following components would NOT be used?

Accepted Answer

A)  fuel injectors 
B)  computer 
C)  mechanical governor 
D)  fuel transfer pump 
A)  fuel injectors 
B)  computer 
C)  mechanical governor 
D)  fuel transfer pump

Question 14

When engine rpm rises and falls at random with no rhythmic pattern, the term used to describe this conditions is:

Accepted Answer

A)  hunting 
B)  insensitivity 
C)  speed drift 
D)  stability 
A)  hunting 
B)  insensitivity 
C)  speed drift 
D)  stability

Question 15

Why is torque rise significant to a truck driver?

Accepted Answer

A)  indicates how fast the engine will turn 
B)  indicates peak power available 
C)  defines upper and lower gear shift points 
D)  define the lugging ability of an engine 
A)  indicates how fast the engine will turn 
B)  indicates peak power available 
C)  defines upper and lower gear shift points 
D)  define the lugging ability of an engine

Question 16

Which of the following terms means the same thing as top engine limit (TEL) in a highway truck engine?

Accepted Answer

A)  peak torque 
B)  rated speed 
C)  overrun rpm 
D)  high idle 
A)  peak torque 
B)  rated speed 
C)  overrun rpm 
D)  high idle

Question 17

How much mechanical leverage can result when a piston throw on the crankshaft forms a 90 degree angle to the piston on its downstroke?

Accepted Answer

A)  none 
B)  minimum 
C)  50% of maximum 
D)  maximum 
A)  none 
B)  minimum 
C)  50% of maximum 
D)  maximum

Question 18

Which of the following has the most influence on the power output of a diesel engine?

Accepted Answer

A)  turbocharger boost pressure 
B)  air flow through intake plenum 
C)  injected fuel quantity 
D)  atomized droplet sizing 
A)  turbocharger boost pressure 
B)  air flow through intake plenum 
C)  injected fuel quantity 
D)  atomized droplet sizing

Question 19

Which variable defines the actual size of fuel droplets emitted from a diesel injector?

Accepted Answer

A)  charging pressure 
B)  orifii size 
C)  injection pressure 
D)  number of multipulse events 
A)  charging pressure 
B)  orifii size 
C)  injection pressure 
D)  number of multipulse events

Question 20

The precise control of injected fuel quantity in a diesel engine is known as:

Accepted Answer

A)  atomization 
B)  pressurization 
C)  metering 
D)  measuring 
A)  atomization 
B)  pressurization 
C)  metering 
D)  measuring

Exam 20: Fuel Injection Basics and Governor Principles

Fuel injected per crank angle degree in a diesel fuel system is known as:

Which of the following would indicate the lowest engine rpm?

What state is atomized fuel in?

In a current direct injected diesel engine governed at 2000 rpm, what droplet size range must the injection system produce?

Why does retarding injection timing tend to produce higher HC emissions?

An engine has a rated speed of 2000 rpm and has 40% torque rise. At what rpm would you expect to find peak torque?

When a crankshaft throw is positioned at exactly TDC, how much mechanical leverage can it apply to the crankshaft?

When a 4-stroke cycle engine rotates at 2000 rpm, how many power strokes occur in any one of its cylinders per second?

When fuel condenses on the piston crown during injection, which of the following can result?

Which of the following governing classifications would allow the accelerator pedal in a truck diesel engine to respond like that in an automobile?

When a hydromechanical governor throttle is snapped (to full fuel request) under no-load, engine rpm temporarily exceeds the high idle speed. What is the term used to describe this condition?

What is the reason for advancing injection timing as engine speed increases?

When a diesel engine is said to be hydromechanically managed, which of the following components would NOT be used?

When engine rpm rises and falls at random with no rhythmic pattern, the term used to describe this conditions is:

Why is torque rise significant to a truck driver?

Which of the following terms means the same thing as top engine limit (TEL) in a highway truck engine?

How much mechanical leverage can result when a piston throw on the crankshaft forms a 90 degree angle to the piston on its downstroke?

Which of the following has the most influence on the power output of a diesel engine?

Which variable defines the actual size of fuel droplets emitted from a diesel injector?

The precise control of injected fuel quantity in a diesel engine is known as:

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