Deck 29: Fuel Delivery Systems

Question 1

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

Answer 1

True

Question 2

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

Answer 2

False

Question 3

All modern vehicles use a threaded, removable gas cap.

Answer 3

False

Question 4

All fuel tanks have a liquid vapor separator.

Question 5

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

Question 6

Most current fuel pumps are installed inside the fuel tank.

Question 7

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

Question 8

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

Question 9

Fuel tank vapors are vented through the fuel filler cap.

Question 10

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

Question 11

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 12

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

Question 13

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

Question 14

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

Question 15

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

Question 16

All fuel tank fittings are the threaded type.

Question 17

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

Question 18

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

Question 19

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

Question 20

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

Question 21

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

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

Question 22

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 23

When draining 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 24

Fuel tanks may be constructed of all the following EXCEPT:

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

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

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 27

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 answers are correct

Question 28

Technician A says a pressure relief valve opens 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 29

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 30

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

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

Question 31

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 32

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 33

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 34

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 35

The fuel pressure regulator on a returnless fuel system is located ______.

A) inside the fuel tank
B) on the end of the fuel rail
C) on the fuel filter inlet
D) no where-a returnless system has no pressure regulator

Question 36

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 37

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 38

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 39

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 40

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 41

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 42

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 43

Fuel pumps should be tested for ____________________ and ____________________.

Question 44

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

Question 45

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

Question 46

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

Question 47

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 48

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 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

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

A) increase
B) decrease
C) hold steady
D) none of these answers is correct

Question 51

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

Question 52

A vehicle is being 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 53

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

Question 54

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 answers are correct

Question 55

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 56

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

Question 57

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 58

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

Question 59

The fuel strainer is sometimes referred to as a ____________________.

Question 60

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 61

What materials are fuel lines normally made from?

Question 62

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

Question 63

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

Question 64

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

Question 65

Name the two types of threaded fuel line fittings.

Question 66

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

Question 67

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

Question 68

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

Question 69

A fuel pressure test reveals higher than normal fuel pressure. How would you determine the root cause of the problem?

Question 70

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

Question 71

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

Question 72

The arrow printed on a fuel filter must face in what direction?

Question 73

What is the purpose of the pump check valve?

Question 74

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