Automotive computer and Fuel system

Fuel pressure for a gasoline injection system is normally at__.

15-40 psi.

The typical reference voltage fed to sensors is ____ volts.

5

If the noid light does not flash when checking an electronic fuel injector's feed circuit,the cause of the problem may be all of the following except:

A faulty injector.

To dampen pressure pulses in an injection system, a fuel ____ can be used.

Accumulator

A(n) ____ dagnostic test uses the scan tool to order the computer to energizes specific output devices.

Actuator

In a diesel engine, ___ is compressed until it becomes hot enough to ignite the fuel.

Air

Check amount of air entering engine.

Air flow sensor

which of the following is an advantage of gasoline injection over carburetor system?

All of above(better atomization of the fuel,better fuel distribution,increase engine power).

To keep fuel from sloshing across the tank when the vehicle is in motion, most tanks are equipped with ____.

Bluffer

A pressure gauge connected to the fuel pressure test fitting(schrader valve)shows a pressure lower than spec.Technician A says that the low pressure is likely to be caused by a faulty fuel pressure regulator.Technician B says that the fuel pump is possibly at fault.Who is correct?

Both A and B.

Technician A says that a passive sensor can be tested by applying a reference voltage and measuring the voltage drop across the sensor. Technician B says that a passive sensor can be tested by using an ohmmeter to measure its internal resistance. Who is correct?

Both A and B.

Which of the following is not a component of mechanical fuel pump?

Bowl fuel filter.

When a(n) _____ fuel injection system is used, fuel is being injected whenever the engine is running.

CIS

On newer vehicles,a flashing malfunction indicator light warns of a problem that could damage the____.

Catalytic converter

Trouble codes set by an OBD I system can be read manually by each of the following methods, except:

Counting beeps of the vehicle's horn.

Detect engine speed.

Crankshaft position sensor

_____ values produced by a vehicle's computer give electrical operating values of sensors, actuators, and circuits.

Data stream

On-off signals from engine sensors are called ____ signals.

Digital

Open injector

Doesn't spray fuel

Some scan too cartridges can be updated by______new information from a computer.

Downloading

A mechanical fuel pump is usually powered by a(n) ____ on the camshaft.

Eccetric

A(n) _____ fuel pump is usually located in the main fuel line or in the fuel tank.

Electric

Measures engine coolant temperature.

Engine coolant temperature sensor

Alcohol fuel made from farm crop.

Ethanol

A clicking sound from an injector indicates that it is a faulty and should be replaced.

False

EFI tester are designed to be used for checking almost any make of vehicle.

False

Gasohol is usually a blend of 20 percent alcohol and 80 percent gasoline.

False

In a diesel engine,fuel is injected at the end of the compression stroke

False

Light blows of a hammer can be used to seat a new TBI injector.

False

Most electric fuel pumps are of the reciprocating type.

False

Pinpoint tests are wiring checks that are done by piercing wires with sharply pointed meter probes.

False

Plastic lines made of high-strength nylon tubing are used in some fuel system

False

Typical output of an oxygen sensor is 0.5 volts.

False

Vacuum rather than pressure,is the actuating force behind fuel injection system.

False

most paper air filter element can be clenned and reused at least once.

False

tetraethyl lead still widely used as anti-knock additives in gasoline.

False

Mixture of gasoline and alcohol.

Gasohol

Problem in which the circuit has a fixed valve,no output,or an output that is out of specification.

General circuit failure

Problem that does not come and go with varying conditions.

Hard failure

The _____ pipe carries exhaust gases from the exhaust manifold to the catatlytic converter.

Header

The exhaust manifold ____ valve aids starting in cold weather.

Heat

The ____ rating of a gasoline measures its ability to resist knock and ping.

High Octain

Problem that produces a voltage,current,or signal frequency above normal operating parameters.

High-input failure

In a TBI system, fuel is sprayed into the top of the air ____.

Horn

Highly flammable gas.

Hydrogen

The___is not one of the subsystem of an electronic fuel injection system.

Idle solenoid system.

Problem that involves a sensor producing values slightly higher or lower than normal.

Improper range/performance failure

A rich fuel mixture will ____ fuel consumption.

Increase

Which method of EEPROM programming involves the use of a scan tool?

Indirect program.

Measure temperature of air entering the engine.

Intake air temperature sensor

A(n) _____ fuel injection system opens and closes injectors independently of the engine's intake valves.

Intermittent

A dual exhaust system is most common on___engine.

Large engine.

Alternate fuel often used in industrial engine.

Liquefied petroleum gas

Problem that produce a voltage ,current,or signal frequency below normal operation parameters.

Low-imput failure

Dirty injector

Makes fuel mixture too lean.

Leaking injector

Makes fuel mixture too rich

Measures vacuum at engine intake.

Manifold absolute pressure (MAP) sensor

All of the following are active sensors, except:

Mass airflow sensor.

Electronic _____ injection systems use one injector for each engine cylinder.

Multipoint

Before servicing some EFI systems, you must disconnect the ____ battery terminal.

Negative

Technician A says the ideal ,chemically correct fuel mixture is 14 parts air to 1 part fuel.Technician B says that 15 air to 1 part fuel is the right ratio.Who is correct?

Neither.

A(n) ____ switch will turn off the electric fuel pump in the event of a collision.

Neutral

The most common fuel for automotive diesel engines is ___ diesel oil.

No. 2

A special test light designed for checking EFI feed circuits is called a(n) ____ light.

Noid

The on-board diagnostic system in older vehicle is referred to as __.

OBD I

A(n) _____ can be used to check the operation of EFI engine sensors; so can a test light or a digital meter.

Ohmmeter

A switching sensor can be checked for proper operation with a(n)____.

Ohmmeter.

Vehicles equipped with ____ systems can set trouble codes that pinpoint injector problems.

On board Diagnostic

For system using a carburetor,fuel pump volume output should be approximately___in 30 sec.

One pint.

An active sensor generates its own ____ .

Output voltage

Checks exhaust gas for combustion efficiency.

Oxygen sensor

_____ numbers identify the location and purpose of each terminal in a computer wiring harness connector.

Pin

Preignition will cause____in the engine.

Ping.

Which of the following is not a common method used to control fuel injection system?

Pneumatic system.

Modern scan tools provide step-by-step instruction called___.

Prompts

A throttle position sensor should produce specific _____ readings at various throttle openings.

RPM

An integrated junction block holds most or all of the vehicle's mechanical ____ in a single housing.

Relay

The catalytic converter is designed to ___.

Remove pollutants from the engine's exhaust.

A knock sensor tells the computer to ____ the timing if the engine starts to knock.

Retard

Impeller, roller vane, and sliding vane fuel pumps are all ____ types.

Rotary

The wiring diagram or _____ for the computer system is found in a shop manual.

Schematic

Using an incorrect ______ can poison an oxygen sensor.

Sealant

Heat ______ must always be replaced after exhaust system repairs.

Sheild

Problem that occurs on intermittently.

Soft failure

An OBDII system will identify problems with all the components listed, except:

Starter Solenoid.

When checking a multiport injection system, a(n) ____ weill help you verify the operation of individual injectors.

Stethoscope

The perfect air-fuel ratio for combustion in an engine is called a(n) ____ fuel mixture.

Stoichio metric

A(n) ____sensor acts as either a conductor or insulator.

Switching

Fuel made from coal or tar sand.

Synthetic fuel

Technician A says that wearing an anti-static wrist strap is an effective means of preventing damage when working on computer circuits. Technician B says that disconnecting the vehicle's battery is sufficient. Who is correct?

Technician A.

Technician A says that both OBD I and OBD II systems will pinpoint a sensor that is operating poorly or incorrectly. Technician B says that OBD I will only indicate that a circuit is no longer operating properly. Who is correct?

Technician B.

A cold-start injector is active by a(n)__.

Thermo-time switch

Monitor throttle plate shaft rotation.

Throttle position sensor

Key-on/engine-off diagnostics allow the technician to check for___.

Trouble codes

OBD II requires manufactures to use a set of standardized

Trouble codes

A lean air-fuel mixture result in poor gas mileage.

True

A modern scan tool allows the technician to monitor operating conditions while performing a test drive

True

A nick or dent in a turbocharger can cause severe vibration.

True

A scan tool is now the most important tool of automobile technician.

True

A throttle positioner is used to control high-speed operation.

True

All vehicles with 16-pin data link connectors are OBD II compliant.

True

Diesel fuel does not vaporize as easily as gasoline.

True

Disconnecting computer wiring with the ignition key on can cause damage to the computer.

True

EEPROM chips are usually soldered to the computer's circuit board. They are not removable.

True

Fuel pressure in an injection system can be high as 40 psi.

True

Fuel tanks should be emptied before dismounting from the vehicle for service.

True

In CIS injection system,the injection deliver fuels intermittently .

True

In a sequential fuel injection system,the injectors open one after the other,instead of all at one time.

True

In an air induction system,flow of air into the engine is controlled by throttle valve.

True

In an direct injection system,the fuel is forced into the combustion chamber itself.

True

OBD II requires all automotive manufactures to use a set of standardized trouble codes.

True

One reason for a poor injector spray pattern is a dirty nozzle.

True

Since they have moving contact points, relays are often a source of computer system problems.

True

To test an EFI system,an oscilloscope can sometimes be used.

True

Vacuum leaks can affect the operation of a vehicle's computer system

True

Water and acid in engine exhaust can cause exhaust system to parts to fail in a fairly short time.

True

Without a scan tool, it is not possible to recover trouble codes from an OBD II system.

True

once an engine stop running,pressure in the EFI system is automatically relieved.

True

problem with clogged fuel filter are most apparent at higher speed.

True

Before testing or servicing any system, the technician should ____ the problem to be sure it is described accurately.

Verify

On turbocharger,the___prevents producing too much pressure in the combustion chambers.

Waste gate.

You should never try to _____ a fuel tank, since an explosion could result.

Weld on

Loose dirty,or corroded electrical connections often can be found by using a(n)_____test

Wiggle

The fuel return system helps ____ the fuel to prevent vapor lock.

cool

After system repairs are made, trouble codes should be _____ to prevent a possible misdiagnosis by the next technician to work on the vehicle.

erased

Each of the following is a type of supercharge,except:

reciprocating.

A faulty fuel tank ____ unit can make the fuel gauge reading inaccurate.

sending

Mechanical fuel pumps usually must be replaced,rather than service,when defective.

true

The data link connector for an OBD II system most often will be located:

under the dash or center console, near the driver's seat.