Deck 41: Fuel System Service

Question 1

There are codes for many malfunctions that the computer can diagnose. The easy way to read these codes is to use a(n) ____________________, a hand-held diagnostic tool.

Answer 1

scan tool

Question 2

The tool that MOST-Likely uses crushed walnut shells blasted by compressed air to remove carbon deposits is:

A)scan tool
B)plenum
C)carbon blaster
D)resonator

Answer 2

C

Question 3

A bad ____________________ sensor can cause a change in idle speed, a stumble on acceleration, or engine stalling.

Answer 3

throttle position

Question 4

Which of the following is LEAST-Likely one of the common adjustments made to EFI systems?

A)Idle speed
B)ISC motor pintle
C)Idle air control
D)Idle fuel filter

Question 5

The exhaust stream from a running engine can be tested using an infrared exhaust analyzer.

Question 6

All of the following statements are true EXCEPT:

A)a pressure regulator can become defective due to foreign material or a ruined diaphragm.
B)high pressure is usually caused by a bad pressure regulator or on looped systems when a pressure return line to the fuel tank is kinked.
C)if gasoline drips from the vacuum hose when it is removed from a fuel pressure regulator, it is defective.
D)fuel pressure regulators usually fail by causing pressure that is too high rather than too low.

Question 7

All of the following statements are true EXCEPT:

A)fumes from some types of silicone RTV sealants used on the engine can contaminate O₂ sensors.
B)lead in fuel can contaminate an O₂ sensor.
C)if the pores of an O₂ sensor become plugged, its response time and output voltage will increase.
D)carbon buildup on an O₂ sensor can be from an overly rich air-fuel mixture, engine oil consumption, or a bad turbocharger turbine seal.

Question 8

If there are three or four wires coming from the sensor, it is a(n) ____ sensor.

A)O₂
B)heated
C)throttle position
D)oxygen

Question 9

Computer fuel injection systems use ____________________ trim to continually adjust the air-fuel ratio in response to both immediate (short-term) and long-term conditions.

Question 10

The sensor that measures the temperature of incoming air is called a(n) ____ sensor.

A)air charge temperature
B)O₂
C)throttle position
D)idle speed

Question 11

Testing pressure in one type of throttle-body fuel injection requires that the line entering the throttle body be disconnected.

Question 12

Before a pressure gauge is installed, be sure the fuel system is fully pressurized.

Question 13

A glitch is when the car stumbles when first accelerated.

Question 14

____________________ occurs when an engine gets too much fuel.

Question 15

Which of the following statements is LEAST-Likely true?

A)The fuel tank is connected to a vapor recovery device.
B)To inspect a hose, flex it back and forth to see if it breaks or shows cracks.
C)Be sure that a hose is not positioned near any part of the exhaust system or the catalytic converter.
D)Most industry authorities recommend that hoses be replaced every five years.

Question 16

While having a discussion, Technician A says that an unfortunate result of a restricted filter is that the fuel pump will draw more electrical current. Technician B says that the result of a restricted filter can be hard on the fuel pump brushes and can result in premature failure of the pump. Who is correct?

A)A only
B)B only
C)Both A and B
D)Neither A nor B

Question 17

Driving at 55 mph into a slight wind will MOST-Likely cause an engine to run with:

A)5" of intake manifold vacuum
B)10" of intake manifold vacuum
C)15" of intake manifold vacuum
D)20" of intake manifold vacuum

Question 18

If the fuel filter becomes plugged in a fuel injection system, fuel to the rail will increase, which results in hard starting, lean running conditions, and lack of power.

Question 19

A leak in an intake manifold gasket can allow air into the engine that is not measured by an airflow sensor. This is called ____________________.

Question 20

While having a discussion, Technician A says that typically, engine knock occurs under load. Technician B says that carbon knock can occur even when not under load. Who is correct?

A)A only
B)B only
C)Both A and B
D)Neither A nor B

Question 21

It is sometimes necessary to lower or remove a fuel tank from a car when the tank is corroded or at what other times?

Question 22

Describe one way to bleed pressure from a fuel system.

Question 23

What precautions should you take when servicing continuous injectors?

Question 24

How would you use a carbon blaster to remove carbon deposits?

Question 25

What precautions should you take when bleeding pressure from a fuel system?