Deck 23: Gasoline Direct-Injection Systems

Question 1

Where is the fuel injected in an engine equipped with gasoline direct injection?

A) Directly into the combustion chamber
B) Into the intake manifold near the intake valve
C) Above the intake port
D) In the exhaust port

Answer 1

A

Question 2

The fuel pump inside the fuel tank on a vehicle equipped with gasoline direct injection produces about what pressure?

A) 10 to 20 PSI
B) 20 to 40 PSI
C) 50 to 60 PSI
D) 5 to 10 PSI

Answer 2

C

Question 3

The high-pressure fuel pumps used in gasoline direct injection (GDI) systems are powered by ________.

A) electricity (DC motor)
B) the crankshaft
C) the camshaft
D) electricity (AC motor)

Answer 3

C

Question 4

The high-pressure fuel pressure is regulated by using ________.

A) a vacuum-biased regulator
B) an electric pressure control valve
C) a non-vacuum-biased regulator
D) a mechanical regulator at the inlet to the fuel rail

Question 5

GDI fuel injectors operate under a pressure of about ________.

A) 500 to 2,900 PSI
B) 2,000 to 5,000 PSI
C) 90 to 150 PSI
D) 35 to 45 PSI

Question 6

The fuel injectors used on a gasoline direct injection system are pulsed ON using what voltage?

A) 100 to 110 V
B) 12 to 14 V
C) 200 to 220 V
D) 50 to 90 V

Question 7

Which mode of operation results in a richer air-fuel mixture near the spark plug?

A) Stoichiometric
B) Homogeneous
C) Knock protection
D) Stratified

Question 8

All of the following are advantages of gasoline direct injection EXCEPT ________.

A) improved fuel economy
B) decreased throttle response
C) able to use lower-octane gasoline
D) higher engine efficiency

Question 9

All of the following are disadvantages of gasoline direct injection EXCEPT ________.

A) more components compared to port fuel injection
B) less need for extra fuel for acceleration
C) higher cost
D) NOx storage catalyst may be needed

Question 10

A lack of power from an engine equipped with gasoline direct injection could be due to ________.

A) noisy injectors
B) carbon on the intake valves
C) carbon on the injectors
D) Both B and C

Question 11

Some engines that use a GDI system have carbon issues ________.

A) on the fuel injectors
B) on the intake valves
C) on the exhaust valves
D) Both A and C

Question 12

Why should any high-pressure line removed be replaced with a new part on a GDI system?

A) The ball-ends deform when tightened and will not seal if reused
B) The torque needed to remove the lines causes the lines to be damaged
C) The high-pressure lines are part of the high-pressure pump and must be replaced as an assembly
D) All of the above

Question 13

GDI equipped engines have a higher efficiency due to a ________ compression ratio.

A) higher
B) colder
C) related
D) lower

Question 14

Gasoline direct injection (GDI) is also known as ________.

A) EFI
B) DI
C) UIDI
D) SIDI

Question 15

An engine equipped with GDI may have up to a ________ percent improvement in fuel economy.

A) 25
B) 6
C) 50
D) 10

Question 16

The SIDI high pressure fuel pump uses a single-barrel piston plunger that is driven by a(n) ________.

A) three-lobed cam
B) electric motor
C) single flat sided cam
D) square-lobed cam

Question 17

When the fuel pressure regulator is deactivated, the fuel pressure defaults to ________.

A) high pressure mode
B) 60 PSI
C) low pressure mode
D) acceleration mode

Question 18

A GDI system operating in stratified mode results in ________.

A) the air-fuel mixture being evenly distributed in the combustion chamber
B) black smoke from the exhaust
C) a rich air-fuel mixture near the spark plug tip
D) None of these

Question 19

What GDI operating mode is used to burn sulfur from the NO_x catalyst?

A) Stratified heating mode
B) Homogeneous stratified mode
C) Stratified mode
D) None of these

Question 20

When compared to a port fuel injected engine, a GDI engine will have a(n) ________ compression ratio.

A) reversed
B) interrupted
C) lower
D) higher

Question 21

Which component of this GDI high pressure pump is the pressure regulator?

A) A
B) B
C) C
D) D

Question 22

This illustration shows a ________ type of combustion chamber.

A) wall-guided
B) tumble-guided
C) spray-guided
D) swirl-guided