Natural Gas For Vehicle System

What is the CNG stands for?

• Compressed Natural Gas

• Compression and Gas

• Combustible Natural Gas

• Coloured Natural Gas

Which gas is present in CNG?

• Oxygen

• Carbon Monoxide

• Methane

• Butane

What is the difference LPG and CNG?

• CNG mainly methane compressed while LPG is a mixture of propane liquefied.

• CNG mainly hydrogen compressed while LPG is a mixture of propane and butane liquefied.

• CNG mainly methane compressed while LPG is a mixture of propane and butane liquefied.

• CNG mainly oxygen compressed while LPG is a mixture of propane and butane liquefied.

What is the maximum pressure for a NGV tank can withstand?

• 200 Bar or 20000 kpa.

• 210 Bar or 21000 kpa

• 180 Bar or 18000 kpa.

• 150 Bar or 15000 kpa

Describe the different between first and second generation for NGV system.

• Gas delivery differences which first generation is using mixer while second generation is using carburettor.

• Method of metering natural gas from tank is different.

• First generation is combining with carburettor fuel system while second generation is combining with electronic fuel injection.

• Gas delivery differences which first generation is using mixer while second generation is using gas injector.

Why the NGV pressure regulators become freezing while in operation?

• Due to gas pressure decrease can cause the temperature drop.

• Due to gas pressure stabilize can cause the temperature drop.

• Due to gas flow increase can cause the temperature drop.

• Due to gas pressure increase can cause the temperature drop.

Define the NGV ignition emulator function in second generation system.

• Function to lower gas flow injection.

• Emulator will advance the ignition timing during NGV operation.

• Function to high gas flow injection.

• Controlling the gas pressure.

Which one of the following correctly describes the gas flow of a compress natural gas engine?

• Tank - lines - regulator - mixer.

• Tank - regulator - lines - mixer.

• Tank - valve - lines - mixer.

• Tank - regulator - lines - valve.

What is the purpose of natural gas for vehicle (NGV) engine regulator?

• Proportioning NGV gas from tank.

• Metering NGV gas from tank.

• Regulate NGV gas pressure from tank.

• Residual NGV gas from tank.

Using a diagnostic strategy for a drivability concern, which of the following is generally the last step in that process to identify compress natural gas vehicle problems?

• Checking vehicle history.

• Verifying repair.

• Doing service checks.

• Verifying concern.