Automotive and Mechanics Fuel Systems & Combustion

Question 1

What is the stoichiometric air-fuel ratio for gasoline engines?

Accepted Answer

14.7:1

Answer

12.5:1

Answer

16.1:1

Answer

10.3:1

Question 2

Which fuel system component regulates fuel pressure delivered to the injectors?

Accepted Answer

Fuel pressure regulator

Answer

Fuel pump

Answer

Fuel filter

Answer

Fuel rail

Question 3

What causes a rich air-fuel mixture condition in a fuel-injected engine?

Accepted Answer

Faulty MAF sensor reading high

Answer

Vacuum leak

Answer

Clogged fuel injector

Answer

Low fuel pressure

Question 4

What is the purpose of a returnless fuel system?

Accepted Answer

Keeps fuel in the tank cooler by not returning hot fuel

Answer

Eliminates the fuel pressure regulator entirely

Answer

Allows higher fuel pressure

Answer

Reduces the number of injectors needed

Question 5

Which type of fuel injection sprays fuel directly into the combustion chamber?

Accepted Answer

Direct injection

Answer

Port fuel injection

Answer

Throttle body injection

Answer

Multi-point injection

Question 6

What does a knock sensor detect in an engine?

Accepted Answer

Abnormal combustion (detonation)

Answer

Camshaft position

Answer

Exhaust backpressure

Answer

Fuel rail pressure