Question 1

CNG

Accepted Answer

Compressed Natural Gas used as fuel for transit bus engines

Question 2

Stoichiometric

Accepted Answer

Fuel-air mixture with the perfect balance for combustion

Question 3

Lean-Burn

Accepted Answer

Fuel-air mixture containing excess air for efficient combustion

Question 4

Combustion

Accepted Answer

Chemical reaction between fuel and oxygen resulting in energy release

Question 5

Emissions

Accepted Answer

Gaseous byproducts released during engine combustion

Question 6

Dual-Fuel System

Accepted Answer

Engine capable of running on CNG and diesel simultaneously

Question 7

Bi-fuel System

Accepted Answer

Engine capable of running on CNG or gasoline interchangeably

Question 8

Spark Ignition

Accepted Answer

Ignition system using a spark plug to ignite the fuel-air mixture

Question 9

Timing Advance

Accepted Answer

Adjustment of spark ignition timing for optimal engine performance

Question 10

High-Pressure Regulator

Accepted Answer

Device that controls the pressure of CNG supplied to the engine

Question 11

Fuel Rail

Accepted Answer

Component that delivers CNG from the high-pressure regulator to the injectors

Question 12

Injectors

Accepted Answer

Devices that deliver CNG into the engine cylinders for combustion

Question 13

Compressor

Accepted Answer

Device that pressurizes natural gas for storage in CNG tanks

Question 14

Fuel Storage Cylinder

Accepted Answer

Tank used for storing CNG on the vehicle

Question 15

Fuel Shutoff Valve

Accepted Answer

Valve that stops the flow of CNG to the engine in case of emergency

Question 16

Check Valve

Accepted Answer

Valve that prevents reverse flow of CNG in the fuel system

Question 17

Fuel Filter

Accepted Answer

Component that removes impurities from the CNG before it reaches the engine

Question 18

Fuel Pressure Sensor

Accepted Answer

Sensor that measures the pressure of CNG in the fuel system

Question 19

Fuel Temperature Sensor

Accepted Answer

Sensor that measures the temperature of CNG in the fuel system

Question 20

Ignition Control Module

Accepted Answer

Module that controls the spark ignition timing

Question 21

Oxygen Sensor

Accepted Answer

Sensor that measures the oxygen content in the exhaust gases

Question 22

Catalytic Converter

Accepted Answer

Device that reduces harmful emissions in the exhaust gases

Question 23

Air-Fuel Ratio Sensor

Accepted Answer

Sensor that measures the air-fuel mixture ratio in the engine

Question 24

EGR (Exhaust Gas Recirculation)

Accepted Answer

System that recirculates a portion of the exhaust gases back into the engine

Question 25

OBD (On-Board Diagnostics)

Accepted Answer

System that monitors and detects engine malfunctions

Question 26

PCM (Powertrain Control Module)

Accepted Answer

Electronic control unit that manages the engine operation

Question 27

MAP (Manifold Absolute Pressure) Sensor

Accepted Answer

Sensor that measures the intake manifold pressure

Question 28

TPS (Throttle Position Sensor)

Accepted Answer

Sensor that measures the position of the throttle valve

Question 29

Knock Sensor

Accepted Answer

Sensor that detects abnormal engine combustion and detonation

Question 30

Fuel System Leak Test

Accepted Answer

Procedure to check for fuel leaks in the CNG system

Question 31

Fuel System Depressurization

Accepted Answer

Procedure to remove pressure from the CNG system for maintenance

Question 32

Fuel System Ventilation

Accepted Answer

Process of venting CNG vapors safely to the atmosphere

Question 33

CNG Fueling Station

Accepted Answer

Station where CNG vehicles refuel with compressed natural gas

Question 34

CNG Fuel Quality

Accepted Answer

Standards and specifications for acceptable CNG fuel composition

Question 35

Flash Arrestor

Accepted Answer

Device that prevents flame propagation in case of a backfire

Question 36

CNG Leak Detection System

Accepted Answer

System that detects and alerts for CNG leaks in the vehicle

Question 37

CNG Tank Inspection

Accepted Answer

Procedure to visually inspect CNG tanks for damage or corrosion

Question 38

Fuel System Diagnostics

Accepted Answer

Process of troubleshooting and identifying issues in the CNG fuel system

Question 39

Fuel System Maintenance

Accepted Answer

Scheduled tasks to ensure proper functioning of the CNG fuel system

Question 40

CNG Safety Precautions

Accepted Answer

Guidelines to follow when working with CNG vehicles and fuel systems

Question 41

CNG System Decompression

Accepted Answer

Process of releasing pressure from the CNG system before maintenance or repairs

Question 42

CNG System Venting

Accepted Answer

Procedure to safely release CNG vapors from the system during maintenance

Question 43

CNG System Purging

Accepted Answer

Process of removing air and contaminants from the CNG system

Question 44

CNG System Inspections

Accepted Answer

Regular checks to ensure the integrity and functionality of CNG system components

Question 45

CNG System Retrofit

Accepted Answer

Conversion of a traditional fuel system to run on CNG

Question 46

CNG System Upgrades

Accepted Answer

Enhancements made to the CNG system for improved performance or efficiency

Question 47

CNG Cylinder Inspection

Accepted Answer

Examination of CNG cylinders for physical damage or wear

Question 48

CNG Cylinder Hydrostatic Testing

Accepted Answer

Pressure testing of CNG cylinders to ensure their safety and integrity

Question 49

CNG Cylinder Requalification

Accepted Answer

Process of renewing the certification of CNG cylinders after a specific period

Question 50

CNG Cylinder Replacement

Accepted Answer

Substituting a damaged or expired CNG cylinder with a new one

Question 51

CNG Fueling Procedure

Accepted Answer

Steps to follow when refueling a CNG-powered transit bus

Question 52

CNG Fueling Nozzle

Accepted Answer

Device used to connect the fueling station to the CNG vehicle

Question 53

CNG Fueling Pressure

Accepted Answer

The recommended pressure at which CNG should be filled into the vehicle

Question 54

CNG Fueling Time

Accepted Answer

Duration required to fully refuel a CNG-powered transit bus

Question 55

CNG Fueling Safety

Accepted Answer

Precautions to observe during the CNG refueling process

Question 56

CNG Fueling Station Equipment

Accepted Answer

Components and systems used at CNG fueling stations

Question 57

CNG System Ventilation

Accepted Answer

Process of removing accumulated CNG vapor from enclosed spaces

Question 58

CNG System Troubleshooting

Accepted Answer

Steps to identify and resolve issues with the CNG system

Question 59

CNG System Maintenance Schedule

Accepted Answer

Regular tasks to ensure the optimal performance of the CNG system

Question 60

CNG System Service Intervals

Accepted Answer

Recommended time intervals for maintenance and inspections of the CNG system

Question 61

CNG System Component Replacement

Accepted Answer

Substituting faulty or worn-out components in the CNG system

Question 62

CNG System Performance Testing

Accepted Answer

Assessing the efficiency and functionality of the CNG system

Question 63

CNG System Software Updates

Accepted Answer

Updating the electronic control modules and software in the CNG system

Question 64

CNG System Failure Modes

Accepted Answer

Common malfunctions and issues that can occur in the CNG system

ASE Transit Bus Certification: CNG Engines Flashcards