Deck 29: Fuel Delivery Systems

Question 1

The fuel strainer serves as a filter, stopping any rust or dirt that may be in the fuel from entering into the fuel pump.

Answer 1

True

Question 2

All modern fuel tanks can only be filled to 90 percent of their capacity.

Answer 2

True

Question 3

During its evaporative system integrity test, the canister vent solenoid is open to vent the entire evaporative system.

Answer 3

False

Question 4

Copper tubing can be used to replace steel tubing for fuel lines.

Question 5

Some states mandate a gas cap check as part of the annual emissions tests.

Question 6

All current gasoline fuel tank filler tubes have a built-in restrictor that prevents the entry of the larger leaded fuel delivery nozzle at gas pumps.

Question 7

In a returnless system, the pressure regulator is in the fuel tank and excess fuel is released to the tank.

Question 8

Most current fuel pumps are installed inside the fuel tank.

Question 9

The fuel pump check valve is normally located in the fuel rail.

Question 10

On a GM vehicle, a defective fuel pump relay will prevent the engine from running.

Question 11

All quick-disconnect fuel line fittings are hand releasable and do not require special tools to disconnect.

Question 12

All modern vehicles use a threaded, removable gas cap.

Question 13

On modern vehicles, the fuel pump is shut off when the air bag is deployed.

Question 14

Fuel tank vapors are vented through the fuel filler cap.

Question 15

A loose gas cap cannot cause the MIL light to turn on.

Question 16

All fuel tanks have a liquid vapor separator.

Question 17

Some vehicles have two fuel pumps: an in-tank pump and a second pump mounted under the vehicle.

Question 18

All fuel tank fittings are the threaded type.

Question 19

A scan tool can be used to turn on the fuel pump when the engine is not running.

Question 20

The negative battery cable should be disconnected before working on the fuel system.

Question 21

Fuel pressure readings are being discussed. Technician A says high fuel pressure can be caused by a defective pressure regulator. Technician B says low fuel pressure can be caused by a defective pressure regulator. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 22

Technician A says the best method for permanently solving a leaking metal fuel tank is to replace the tank. Technician B says a leaking plastic fuel tank can sometimes be repaired. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 23

OBDII evaporative system integrity testing is being discussed. Technician A says the integrity check is done by creating a vacuum in the tank and measuring how well it holds the vacuum. Technician B says the fuel tank pressure (FTP)sensor is a transducer that converts the absolute pressure in the fuel tank into an input for the PCM. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 24

Technician A says the gas cap is equipped with a pressure release valve that opens if there is excess vapor pressure in the fuel tank. This prevents tank ballooning. Technician B says the gas cap is equipped with a vacuum relief valve that opens if there is an excessive amount of vacuum in the fuel tank. This prevents tank collapse. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 25

On a modern common rail diesel (DI)direct injection system fuel pressure is typically ______ psi.

A)26
B)260
C)2,600
D)26,000

Question 26

What class of fire extinguisher should be used on gasoline fires?

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

Question 27

A vehicle with a leaking nylon fuel supply line is being repaired. Technician A says replace the nylon fuel line with a section of double-wall steel fuel line, using short lengths of rubber fuel hose and screw clamps to connect to the filter and fuel tank to the steel line. Technician B says use an OEM nylon fuel line assembly. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 28

Fuel line fittings are being discussed. Technician A says that O-rings are used on some fuel line fittings. Technician B says that clamps are used on some systems. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 29

Technician A says low fuel pressure can be caused by a restricted fuel filter. Technician B says low fuel pressure can be caused by a kinked fuel return line. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 30

Which of the following is a typical fuel filter replacement interval?

A)30,000 miles (48,280 km)
B)100,000 miles (160,000 km)
C)50,000 miles (80,470 km)
D)15,000 miles (24,140 km)

Question 31

The fuel filter on a modern car is typically mounted ______.

A)under the car
B)on the end of the fuel rail
C)on the intake manifold
D)on the side of the engine block

Question 32

The first step in removing a fuel tank is to ______.

A)drain the tank
B)loosen the retaining straps
C)remove the negative battery cable
D)raise the vehicle on a lift

Question 33

Fuel tanks may be constructed of all the following EXCEPT:

A)aluminum
B)steel
C)plastic
D)brass

Question 34

When emptying a fuel tank, Technician A drains the fuel into plastic antifreeze containers then caps them tightly to prevent leaks. Technician B drains the fuel into approved gasoline storage containers. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 35

Technician A says a pressure relief valve closes if the fuel supply line is restricted and pump pressure becomes very high. Technician B says the check valve in the pump prevents fuel from draining out of the fuel system and back into the fuel tank. This helps holds residual pressure in the fuel lines after the pump is turned off. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 36

A plugged fuel filter will cause ______.

A)high speed surge
B)loss of power at high speed (cut out)
C)hesitation on acceleration
D)All the answers are correct.

Question 37

Fuel lines are being discussed. Technician A says when installing flexible tubing, always use new clamps. Technician B says ordinary rubber hose may be used to replace a kinked steel fuel line. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 38

A high fuel pressure reading is typically caused by a faulty fuel ______.

A)pump
B)pressure regulator
C)filter
D)tank

Question 39

Where is the fuel pressure regulator on a returnless fuel system?

A)inside the fuel tank
B)on the end of the fuel rail
C)on the fuel filter inlet
D)on the fuel line near the fuel tank

Question 40

Residual fuel pressure is being discussed. Technician A says remove the fuel filter hose and apply compressed air to the fuel line to push the residual fuel back into the fuel tank. Technician B says to relieve the residual pressure by connecting a fuel gauge with a bleed valve to the Shrader valve. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 41

A vehicle has been diagnosed with a low fuel pressure problem. A fuel pump current test reveals higher than normal current flow. Technician A says the vehicle may have a clogged fuel filter. Technician B says the fuel pump ground wire may be loose or corroded. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 42

Technician A says the inertia switch has a reset button that must be depressed for at least one second before the pump will operate again. Technician B says the inertia switch is triggered by the ABS control module. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 43

A no start/no fuel pressure condition is being diagnosed. When a test light is connected to the pump positive terminal, there is no voltage when the engine is cranked by the starter. What could cause this problem?

A)defective neutral safety switch
B)bad fuel pump ground
C)defective fuel pressure regulator
D)defective fuel pump relay

Question 44

A pressure ____________________ can be used to connect a DMM (or lab scope)to the fuel system to measure fuel pressure.

Question 45

An in-tank electric pump is usually the ____________________ type.

Question 46

Gas cap testing is being discussed. Technician A says the tester applies twenty inches of vacuum to the cap and measures its rate of leakage. Technician B says if the wrong adapter was used, the cap will fail the test even if it is good. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 47

A fuel system that runs at 35 to 50 psi should draw around _____ amps of current.

A)2 to 4
B)4 to 9
C)9 to 13
D)15 to 18

Question 48

When a vehicle will not start because of no fuel delivery, the first check should be the ____________________.

Question 49

Which of the following problems could NOT cause the fuel pressure to drops off quickly after the engine and ignition are turned off.

A)leaking injector
B)internally leaking fuel pump check valve
C)internally leaking fuel pressure regulator
D)restricted fuel filter

Question 50

The fuel strainer is sometimes referred to as a ____________________.

Question 51

Technician A says on some vehicles the fuel pressure is monitored by a fuel rail pressure sensor and the output of the fuel pump is controlled by the PCM through pulse-width modulation. Technician B says all fuel pumps on late-model vehicles are controlled by the PCM according to inputs received on the CAN bus and other specific sensors.Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 52

Fuel pumps should be tested for ____________________ and ____________________.

Question 53

Technician A connects a fuel pressure gauge to the Schrader valve on the fuel rail. Technician B connects the gauge to the fuel lines by inserting a tee adapter between the fuel filter and the fuel rail. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 54

A(n)____________________ switch shuts off the fuel pump if the vehicle in involved in a collision or rolls over.

Question 55

A restricted fuel filter will cause ____________________ than normal fuel pressure.

Question 56

If a vehicle is to be stored for several months, a fuel ____________________ should be added to the gasoline in the fuel tank.

Question 57

If twenty inches of vacuum is applied to the fuel pressure regulator while the fuel pump is running, the fuel pressure should ____________________  .

Question 58

A loss of residual fuel pressure immediately after engine shutdown could cause ______.

A)surging
B)hard starting
C)loss of power at high speed
D)excessive emissions

Question 59

In Chrysler EFI systems, the ASD relay (automatic shutdown)controls the power to the ______.

A)fuel pump
B)injectors
C)positive primary coil terminal
D)All the answers are correct.

Question 60

On many vehicles, the ____________________ must be removed to replace the fuel pump.

Question 61

Quick-disconnect fuel line fittings are sealed by a(n)____________________ inside the female connector.

Question 62

A fuel pressure test reveals higher than normal fuel pressure. Describe the steps you would take to determine the root cause of the problem.

Question 63

What is the first step in removing a fuel tank from a vehicle?

Question 64

What is the purpose of the pump check valve?

Question 65

How can you tell whether the fuel pump runs when the ignition switch is turned on?

Question 66

How can an electric fuel pump be safe when there is a great potential for sparks between an
electric motor's armature and brushes?

Question 67

Where in the fuel system is a fuel filter usually found?

Question 68

Name the two types of threaded fuel line fittings.

Question 69

Name three situations where the PCM automatically turns off the fuel pump.

Question 70

If the fuel system does not have a test port, how can you safely relieve residual fuel pressure?

Question 71

What controls [turns on and off] the fuel pump on most late-model vehicles?

Question 72

Why are most fuel pumps in modern vehicles located inside the fuel tank?

Question 73

In what direction must the arrow printed on a fuel filter face?

Question 74

What materials are fuel lines normally made from?