Week 2, Diesel Fuel PPT

Question 1

Diesel fuel requires _____ maintenance compared to gasoline

Answer 1

More

Question 2

How much pressure is in low pressure diesel fuel systems?

Answer 2

30-70 PSI

Question 3

How much pressure is in high pressure diesel fuel systems?

Answer 3

3,000-42,000 PSI

Question 4

Air fuel ratio of diesel fuel systems is _________

Answer 4

14.5:1

Question 5

What are the three grades of diesel fuels?

Answer 5

1-D
2-D
4-D

Question 6

Which grade of diesel fuel is preferred for cold weather use and has low emissions?

Answer 6

1-D

Question 7

Which grade of diesel fuel is most common and has higher heat content?

Answer 7

2-D

Question 8

Which grade of diesel fuel heats fuel for oil burner furnaces and can be burned in indirect injection engines?

Answer 8

4-D

Question 9

Diesel fuel’s ignitability or ignition quality

Answer 9

Cetane Number

Question 10

Adding more cetane to diesel creates

Answer 10

Shorter ignition delay time (faster ignition)

Question 11

What is a natural part of crude oil?

Answer 11

Sulfur

Question 12

In 1993, diesel fuel was limited to ______ ppm sulfur content

Answer 12

500

Question 13

Reducing sulfur content =

Answer 13

Engine longevity

Question 14

Sulfur and nitrogen molecule that is part of diesel fuel and hard to burn

Answer 14

Aromatic content

Question 15

• Cetane boosters
• Detergents
• Lubricity additives
• Smoke suppressants

These are all examples of what?

Answer 15

Engine performance enhancers

Question 16

• De-icing
• Pour point improvers
• Antifoaming

These are all examples of what?

Answer 16

Fuel-handling additives

Question 17

• Pour point suppressants
• Fuel stabilizers
• Corrosion inhibitors
• Contaminant control
• Biocides

These are all examples of what?

Answer 17

Diesel fuel additives

Question 18

Quantity of a fuel evaporating at a certain temperature

Answer 18

Volatility

Question 19

___________ and ___________ are the temperatures at which wax in diesel fuel crystalizes

Answer 19

Pour point; cloud point

Question 20

_____________ can incorporate relief valve and vacuum relief

Answer 20

Fuel tank cap

Question 21

Return fuel may need to release _____ and as level drops in tank, air must replace void

Answer 21

Air

Question 22

____________ can be used to vent the tank when exposed to fire

Answer 22

Thermal plugs

Question 23

What is the most common type of variable resistance in a sending unit?

Answer 23

Float sensor that moves with fuel level and gauge circuit resistance

Question 24

Placed just above the bottom of the tank to prevent contamination (heavy duty vehicles use these located at the top of the tank)

Answer 24

Tank pickup

Question 25

- Soft particles that occur naturally in 2-D diesel fuel - High heat and oxidation increases content - 1.5-2 microns in diameter

Answer 25

Asphaltenes

Question 26

- Most destructive contaminant - Can seize injectors

Answer 26

Water

Question 27

What contamination source causes... - loss of film strength of diesel fuel - rust - microorganism growth

Answer 27

Water

Question 28

__________________ allow draining of water from filter housing

Answer 28

Filter drain valves

Question 29

_____________ alert operator to water in fuel by either float or electrical conductivity difference

Answer 29

WIF sensors (Water in filter)

Question 30

Grow in fuel under the right conditions and if fuel is left stagnant (can be treated with biocide)

Answer 30

Bacteria and fungi

Question 31

What contamination source.. - Solidifies at cold temperature - Becomes cloudy at 32 degrees F

Answer 31

Wax

Question 32

When fuel filters are replaced, the system needs to have what done to it?

Answer 32

Air purged from the filter and hand primed

Question 33

When are hand primers and priming buttons used?

Answer 33

During engine service

Question 34

What do fuel transfer pumps do?

Answer 34

Moves fuel from tank to high-pressure system

Question 35

Positive displacement pump with two gears

Answer 35

Gear pump

Question 36

Process of breaking larger fuel drops into tiny droplets

Answer 36

Atomization

Question 37

What system uses pressurized engine oil to product high injection pressures and fuel rate control for emission reduction and fuel efficiency?

Answer 37

HEUI systems (Hydraulically activated, Electrically controlled Unit Injector)

Question 38

Mechanically governed fuel systems have limited injection pressure at low idle because of ___________

Answer 38

Low plunger speed

Question 39

HEUI systems produce ______________________ independent of engine speed

Answer 39

High-injection pressure

Question 40

Engine-driven high-pressure oil pump produces up to _______ oil pressure

Answer 40

4,000 PSI

Question 41

___________ injection is possible and provides a smaller pilot injection before main injection

Answer 41

Split shot

Question 42

_______ injection is delivered 8-10 degrees before main injection and begins to burn just as main is delivered

Answer 42

Pilot

Question 43

__________________________ is the most recent development in high-pressure injection systems and is currently used by most diesel engines in production

Answer 43

Common rail fuel injection

Question 44

What kind of fuel system supplies fuel at injection pressure to nozzle that electrically controls injection event?

Answer 44

Common rail fuel systems

Question 45

___________ injectors use servo-hydraulic design, allowing electrical solenoid to trigger servo valve and provide a short duration injection

Answer 45

CR (Common Rail)

Question 46

What kind of fuel injection includes crystals that upon being electrified, expand and provide fuel pressure to spray from the injector?

Answer 46

Piezoceramic Electric Actuators

Question 47

Piezoceramic electric actuators change ___________ of signal to injector which causes instantaneous change in injector control valve

Answer 47

Polarity

Question 48

Variable nozzle lift in a fuel injector is possible by doing what?

Answer 48

Varying the voltage applied

Question 49

Specific gravity is measured in what?

Answer 49

API Units

Question 50

How do you set the calibration on an injector?

Answer 50

There is often a QR code on the injector itself