Deck 19: Diesel Engine Operation and Diagnosis

Question 1

How is diesel fuel ignited in a warm diesel engine?

A)Heat of compression
B)Distributorless ignition system
C)Glow plugs
D)Spark plugs

Answer 1

Heat of compression

Question 2

Which type of diesel injection produces less noise?

A)Distributor injection
B)Indirect injection (IDI)
C)Direct injection
D)Common rail

Answer 2

Indirect injection (IDI)

Question 3

Which diesel injection system requires the use of a glow plug?

A)Distributor injection
B)Indirect injection (IDI)
C)Common rail
D)Direct injection

Answer 3

Indirect injection (IDI)

Question 4

The three phases of diesel ignition include ________.

A)Ignition delay, rapid combustion, controlled combustion
B)Slow burn, fast burn, slow burn
C)Glow plug ignition, ignition delay, controlled combustion
D)Glow plug ignition, fast burn, slow burn

Question 5

What fuel system component is used in a vehicle equipped with a diesel engine that is not usually used on the same vehicle when it is equipped with a gasoline engine?

A)Fuel filter
B)Fuel supply line
C)Water-fuel separator
D)Fuel return line

Question 6

The diesel injection pump is usually driven by a ________.

A)Belt off the crankshaft
B)Shaft drive off of the crankshaft
C)Chain drive off of the camshaft
D)Gear off the camshaft

Question 7

Which diesel system supplies high-pressure diesel fuel to all of the injectors all of the time?

A)Inline
B)Rotary
C)High pressure common rail
D)Distributor

Question 8

Glow plugs should have high resistance when ________ and lower resistance when ________.

A)Warm/cold
B)Dry/wet
C)Cold/warm
D)Wet/dry

Question 9

Technician A says that glow plugs are used to help start a diesel engine and are shut off as soon as the engine starts. Technician B says that the glow plugs are turned off as soon as a flame is detected in the combustion chamber. Which technician is correct?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Question 10

What part should be removed to test cylinder compression on a diesel engine?

A)Intake valve rocker arm and stud
B)Glow plug or injector
C)Glow plug
D)Injector

Question 11

Technician A says that a diesel engine uses the heat of compression to ignite the diesel fuel. Technician B
Says that direct injection (DI) uses a pre-combustion chamber. Who is right?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Question 12

Technician A says that injector nozzles are either opened by the high-pressure pulse from a distributor pump or electrically by the computer on a common rail design. Technician B says that indirect injection (IDI) occurs directly into the combustion chamber. Who is right?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Question 13

Technician A says that diesel engines can be tested using a scan tool to determine sensor values. Technician B says that glow plugs can be used to locate a weak cylinder. Who is right?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Question 14

Which of these takes place during regeneration in a diesel particulate filter (DPF)?

A)Soot is being burned
B)The oxygen sensor is being cleaned
C)EGR system is being actively tested
D)Catalytic converter is being purged

Question 15

A diesel powered vehicle with a manual transmission is rapidly accelerated in low gear from an idle speed to a maximum governed RPM while the smoke emissions are measured. Which of these diesel smoke opacity tests is being performed?

A)Rolling Acceleration Test
B)Snap Acceleration Test
C)Controlled Acceleration Test
D)Stall Acceleration Test

Question 16

What percent of opacity means that the exhaust is so dark that it completely blocks light from a beam projected through the exhaust smoke?

A)0 %
B)25 %
C)100 %
D)50 %

Question 17

What percent of opacity means the exhaust has no visible smoke and does not block light from a beam projected through the exhaust smoke?

A)50 %
B)0 %
C)25 %
D)100 %

Question 18

A diesel engine should produce at least ________ psi of compression pressure and all cylinders should be within 50 psi of each other.

A)450
B)150
C)300
D)250

Question 19

What color exhaust smoke occurs most often during cold engine starts because the smoke is usually condensed fuel droplets?

A)Black
B)Blue
C)Grey
D)White

Question 20

Which of these tools is used for checking a diesel injector nozzle for proper spray pattern?

A)Pop tester
B)Injector test
C)Pattern tester
D)Scan tool

Question 21

Selective catalytic reduction (SCR) uses urea injection to reduce ________ emissions.

A)CO
B)H₂O
C)NOx
D)CO₂

Question 22

The diesel exhaust fluid is injected ________.

A)After the oxidation catalyst
B)Into the exhaust manifold
C)At the end of the tail pipe
D)Just in front of the muffler

Question 23

The diesel particulate filter in the exhaust system is used to trap ________.

A)Soot
B)Rust from inside the exhaust system
C)CO₂ particles
D)Fine sand particles

Question 24

The use of a variable vane turbocharger allows the elimination of the ________.

A)Diesel oxygen sensor
B)Turbocharger wastegate
C)Intake air cooler
D)Exhaust cooler

Question 25

The accelerator pedal position (APP) sensor sends a ________ signal to the engine control computer.

A)Voltage
B)Pressure
C)Balanced
D)Spring

Question 26

High pressure common rail fuel injectors are opened by ________.

A)Solenoids
B)Injector pump pressure
C)Engine oil pressure
D)Either A or C

Question 27

The most common diesel exhaust emission test used in local testing programs is ________.

A)The opacity test
B)A "Check Engine" light test
C)The exhaust temperature test
D)The paper test

Question 28

When compared to a gasoline engine, the diesel engine may be ________ than a similar size engine.

A)Lighter
B)Easier to start in cold weather
C)Heavier
D)Quieter

Question 29

This diesel engine is the ________ type.

A)Low compression
B)Indirect injected
C)Heat injected
D)Direct injected

Question 30

This diesel engine is the ________ type.

A)Heat injected
B)Direct injected
C)Indirect injected
D)Low compression