Engine 2 - Fuel, Ignition, Air and Exhaust

Question 1

What is diesel fuel made of?

Answer 1

87% Carbon
11% nitrogen
1% sulfur

Question 2

What is the meaning of the term flame travel?

Answer 2

Distance across the combustion chamber that the flame of the ignited mixture travels

Question 3

What does NOx mean?

Answer 3

Nitrogen oxide and nitric oxide

Question 4

What does the term octane refer to?

Answer 4

Petrol fuel

Question 5

What does the term cetane refer to?

Answer 5

Diesel fuel

Question 6

What is the purpose of the catalytic converter and what does it turn harmful gases into?

Answer 6

CO2, H2O, Nitrogen

Question 7

What type of exhaust leak is each colour:
Blue smoke
White smoke
Black smoke

Answer 7

Oil
Water
Fuel

Question 8

What does the ‘delay period’ in the combustion process refer to?

Answer 8

The period between fuel being injected into the cylinder and it self-igniting

Question 9

What does a contactless breaker point do in a distributor?

Answer 9

Sends a message to each of the 4 cylinders to ignite, but not by using contact

Question 10

What component replaced the distributor?

Answer 10

Carburetor

Question 11

Referencing ignition, what is low tension and high tension?

Answer 11

Low voltage and high voltage

Question 12

List the 3 components of a pre-carburetor car on the high tension side of the circuit

Answer 12

Distributor, spark plugs, coil

Question 13

List the 3 components of a pre-carburetor car on the low tension side of the circuit

Answer 13

Timing control system, ignition switch battery

Question 14

How is a distributor timed?

Answer 14

Using the camshaft

Question 15

List the 3 types of contactless breaker point sensors used in electronic distributors

Answer 15

Inductive
Optical
Hall effect

Question 16

How do inductive sensors work?

Answer 16

Consists of a coil and a magnet
Distributor shaft rotates and magnatically induces voltage in the coil, which turns on and off the primary circuit using transistors

Question 17

How do optical sensors work?

Answer 17

Laser beams

Question 18

Hall effect sensors are similar to inductive sensors. What is the difference?

Answer 18

Rather than an electronic and magnetic component, there are 2 magnetic components

Question 19

What do passive sensors do?
What do active sensors do?

Answer 19

Detect natural emissions from the target
Emit their own energy and detect the reflection

Question 20

What is the ideal fuel to air ratio inducted into the cylinder?

Answer 20

14.7:1

Question 21

What is a pulse generator most commonly found in?

Answer 21

An electronic ignition system

Question 22

What should you do before checking the exhaust emissions of an engine?

Answer 22

Run the engine until it reaches normal operating temperature

Question 23

What does the injector do in a direct injection compression ignition engine?

Answer 23

Injects the fuel into the cylinder

Question 24

Why are diesel engines fitted with a speed limiting device?

Answer 24

Prevent over revving

Question 25

Give one likely cause of an emissions test showing an excessive amount of Carbon Monoxide.

Answer 25

A defective spark plug

Question 26

What does the term naturally aspirated engine mean?

Answer 26

Air enters the engine at atmospheric pressure

Question 27

What is octane rating a property of?

Answer 27

Petrol

Question 28

What is the ‘delay period’ in the combustion cycle of a CI (diesel) engine?

Answer 28

The period before self-ignition when injected fuel absorbs heat

Question 29

Give one probable cause for engine misfires at all engine speeds?

Answer 29

A defective coil

Question 30

What fault would most likely highlight a defective coolant temperature sensor?

Answer 30

Excessive fuel consumption

Question 31

What will increasing the fuel injector pulse width do?

Answer 31

Inject more fuel

Question 32

What does a hot wire air flow sensor measure?

Answer 32

Airflow mass

Question 33

If an internal combustion engine compresses the intake air greater than atmospheric pressure what is it? 2 descriptions

Answer 33

Turbo-charged

Question 34

Which gas in an EGR system is designed to be reduced?

Answer 34

NOx

Question 35

What does a sequential fuel injection system do?

Answer 35

It delivers fuel to each cylinder in turn

Question 36

What is meant by the ‘flash point’ of a fuel?

Answer 36

The critical temperature at which the fuel will ignite

Question 37

What is cetane rating a property of?

Answer 37

Diesel

Question 38

What is important to do before removing petrol injectors?

Answer 38

Depressurise the fuel pipes

Question 39

On a D.I.S with a coil pack, when a spark occurs on the exhaust stroke it is described as a:

Answer 39

Wasted spark

Question 40

Where are the injectors located in multipoint fuel injection systems?

Answer 40

The inlet manifold

Question 41

What is the name for the fuel injection system which use of a single injector to sprays fuel towards a throttle?

Answer 41

A single point system

Question 42

List 2 exhaust gas products that are NOT harmful in the environment

Answer 42

CO2 and H2O

Question 43

What do direct injection S.I Engines inject fuel into?

Answer 43

The engine cylinder

Question 44

What are the two windings in an ignition coil known as?

Answer 44

Primary and secondary

Question 45

Severely over advanced ignition timing will cause

Answer 45

Pinking

Question 46

Where is the sensor that measures engine position and speed found?

Answer 46

Crankshaft or front pulley

Question 47

Where is the pressure regulator usually located in a multipoint fuel injection system?

Answer 47

On the fuel rail

Question 48

Why will setting spark plug gaps too wide will cause running problems?

Answer 48

The firing voltage will increase and the spark duration will decrease

Question 49

A M.A.P sensor changes ignition timing in relation to engine...

Answer 49

Load

Question 50

What is excessive fuel consumption due to a rich fuel mixture likely to cause?

Answer 50

Black smoke from the exhaust

Question 51

What do turbo-chargers and super-chargers both do?

Answer 51

Compress more air into a smaller space so that when in the cylinder, the compression stage is more powerful

Question 52

What are turbo-chargers powered by? Where do they send air from and to?

Answer 52

A turbine From exhaust and to intake manifold

Question 53

What are super-chargers powered by? Where do they send air from and to?

Answer 53

The crankshaft From outside air and to inlet manifold

Question 54

What are turbo-chargers and super-chargers both in the category of? (2 answers)

Answer 54

Forced induction Dynamic compressors

Question 55

What is the most common type of supercharger?

Answer 55

Centrifugal supercharger

Question 56

What is the typical boost in air pressure caused by a turbo? What is normal atmospheric pressure? So what kind of increase is this?

Answer 56

6 to 8 or 5 to 10 pounds per square inch (psi) 14.7 psi About 50% more

Question 57

What is the typical boost in air pressure caused by a supercharger?

Answer 57

6 to 9 or 5 to 30 psi

Question 58

List components of a turbo