Exam 40: Fuel System Fundamentals

The term MOST-Likely used to describe an event that occurs when the engine reaches operating temperature and the computer starts acting on information received from the O₂ sensor is:

Modern diesel engines have been mandated to have exhaust emissions that are nearly free of particulates.

____________________ is the name of the process by which fuel is suspended in air in a mist of tiny droplets.

Manifold pressure, temperature and density of the air, and engine speed are all considered by the computer before it calculates the correct amount of fuel to inject into the cylinders.

How do the following circuits in a carburetor work: float circuit and choke?

All of the following statements are true EXCEPT:

What does the term returnless mean, as in returnless fuel systems?

____________________ occurs when atomized fuel turns into a gas (vapor).

Carburetors are old technology. The carburetor's job is to atomize air and fuel in the proper proportion.

All of the following statements are true EXCEPT:

What are the characteristics of a returnless fuel system?

A(n) ____________________ controls the system's maximum amount of pressure.

____________________ injection systems are those in which fuel is injected into the intake port at a precise point in relation to crankshaft and piston position.

While having a discussion, Technician A says that GDI has the ability to run the engine with a variable air-fuel mixture that can be extremely lean with an overall average ratio of around 40:1. Technician B says that this can increase fuel economy by as much as 30%. Who is correct?

Which of the following is LEAST-Likely to be included in a fuel tank cluster assembly?

The term MOST-Likely used to describe the ratio of the engine's actual air-fuel mixture in the exhaust to what would be an ideal, or stoichiometric, mixture is:

While having a discussion, Technician A says that a coolant position sensor attached to the throttle body on the air inlet senses how many degrees the throttle plate is open. Technician B says that an air charge temperature sensor senses how many degrees the throttle plate is open. Who is correct?

The mechanical fuel injection systems found on some imported cars are called ____.

Compared to throttle-body injection (TBI) systems, what are the advantages of port fuel injection systems?

With a carburetor, airflow through the engine is changed by opening the vacuum gauge.