Auto 141 Midterm Study Guide

As wire size increases: -Wire resistance decreases -Current carrying capacity increases -Wire voltage drop decreases -All of the above

-All of the above

Technician A says that to find the cause of a battery drain, the fuses may be disconnected one at a time. Technician B says that with the ignition in the off position, computers have a low current drain. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

-Both A and B

A gear ratio greater than 1:1 is called: -Gear reduction -Overdrive -Direct drive -None of the above

-Overdrive

The maximum allowable amount of voltage drop across any one wire or connector is: -.01 volt -.1 volt -1 volt -0 volts

.1 volt

A Hall-effect switch is being analyzed on a lab scope. The high part of the signal measures 5.0 volts. Ideally, what should the low part of the signal read? -0.0 volts -450 millivolts -4.5 volts -2.5 volts

0.0 volts

Approximately how much of an engine's energy is used to drive the vehicle? -25% -20% -15% -10%

15%

An open circuit voltage test may be used in place of: -A battery leakage test -A battery hydrometer test -A battery capacity test -All of the above

A battery hydrometer test

What type of noise will be caused by a piston slap? -A sharp, metallic rapping noise that occurs with the engine idling. -A hollow, rapping noise that is most noticeable on acceleration when the engine is cold. -A light, rapping noise at speeds above 35 mph. -A heavy thumping knock when the engine is first started

A hollow, rapping noise that is most noticeable on acceleration when the engine is cold.

An oscilloscope test shows firing lines the same, but abnormally high. This is the result of: -A rich air/fuel mixture. -Low cylinder compression. -A lean air/fuel mixture. -The spark plug air gap being too close.

A lean air/fuel mixture.

Technician A says that the evaporative emission system (EVAP) must detect a leak from a hole 0.020 in. in diameter beginning in the 2001 model year. Technician B says that the ORVR portion of the evaporative emission system is designed to capture fuel vapors produced during refueling. Who is correct? -Technician A -Technician B -Both -Neither

Both

Moving a conductor through a magnetic field will produce: -DC voltage -AC voltage -Electrical resistance -None of the above

AC voltage

A defective PCV valve can cause: -Increased HC emissions -Oil sludge -Oil leaks -All of the above

All of the above

A transistor can act as: -A conductor -An insulator -Both A and B -Neither A nor B

Both A and B

A waste spark ignition system equipped vehicle has a no-spark condition. Technician A says the crankshaft position sensor may be defective. Technician B says the ignition module may be defective. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Both A and B

Technician A says a SFI requires both crank and cam position sensors. Technician B says SFI engines can also function as MFI if necessary. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Both A and B

Technician A says acceleration stumbles may be the result of restricted injector tips. Technician B says cylinder misfiring at idle speed may be caused by a defective injector. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Both A and B

Technician A says as engine speed slows, the timing should be retarded or have less advance. Technician B says typically, the more load on an engine, the less spark advance is needed. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Both A and B

Technician A says if the IAC value is at or near zero on a speed density system there may be a manifold vacuum leak. Technician B says if the IAC value is too high there may be a build-up of carbon on the backside of the throttle plate. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Both A and B

Technician A says one component of the secondary ignition circuit is the coil. Technician B says the coil is a component in the primary ignition circuit. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Both A and B

Technician A says that central sequential fuel injection (CMFI) uses poppet nozzles located inside the intake manifold. Technician B says this design uses separate electrical fuel injectors. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Both A and B

Technician A says the crankshaft position sensor can be a Hall-effect switch. Technician B says the crankshaft position sensor can be a magnetic pulse generator. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Both A and B

Technician A says the ignition coil is actually where the primary and secondary circuits meet. Technician B says bypass voltage is sent from the ECM to tell the module to switch to computer based timing. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Both A and B

Technician A says the magnetic pick-up may be tested using a voltmeter to measure the AC voltage during cranking. Technician B says the Hall-effect sensor produces a square wave pattern on an oscilloscope. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Both A and B

Technician A says the primary ignition coil can be tested with an Ohmmeter. Technician B says the secondary ignition coil can be tested with an oscilloscope. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Both A and B

The boiling point of the coolant in the engine may be increased by: -Using A 50-50 mixture of antifreeze and coolant -Increasing the pressure of the coolant -Circulating the coolant through the radiator -Both A and B

Both A and B

While discussing the diagnosis of an EI system in which the crankshaft and camshaft sensor tests are satisfactory but a spark tester connected from the spark plug wires to ground does not fire, Technician A says the coil assembly may be defective. Technician B says the voltage supply wire to the coil assembly maybe open. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Both A and B

Which of the following are oxidized in the catalytic converter? -Hydrocarbons -Oxides of nitrogen -Carbon monoxide -Both A and C

Both A and C

Multiport fuel injection systems do not require a: -Crankshaft position sensor -Camshaft position sensor -Engine coolant temperature sensor -Intake air temperature sensor

Camshaft position sensor

Compression sense ignition allows for the elimination of the: -Crankshaft sensor -Camshaft sensor -Spark plug -Knock sensor

Camshaft sensor

A turbocharger: -Compresses exhaust gases -Increases fuel system pressure -Compresses intake air -None of the above

Compresses intake air

The firing voltages of a four cylinder engine are as follows: #1: 8kV; #2: 27kV; #3: 4kV; and #4: 9kV. Which of the following is true? -Cylinder #2 may have an open plug wire. -Cylinder #3 may have an open plug wire. -Cylinder #2 may have an oil-fouled spark plug. -Cylinder #4 may have an oil-fouled spark plug.

Cylinder #2 may have an open plug wire.

Which of the following fuel systems can have fuel pressure of over 1500 psi? -TBI -SFI -MPI -DFI

DFI

If more current is flowing out of the battery than the alternator, it is said to be ____________________.

Discharging

The time during which current flows through the primary coil winding is called: -Saturation -Dwell -Reluctance -Reactance

Dwell

NOx emissions are reduced by the____valve.

EGR

An automotive battery converts chemical energy into: -Thermal energy -Mechanical energy -Electrical energy -None of the above

Electrical energy

A thermistor changes resistance according to pressure. True or False

False

A unit of measured electrical resistance is called an amp. True or False

False

A voltage drop above .2 volts in most starter ground circuits indicates a good circuit. True or False

False

On all modern engines, the crankshaft, camshaft, and valves are located within the engine block. -True -False

False

The American Petroleum Institute (API) is a technical society that has established a classification system that standardizes oil viscosity ratings. True or False

False

The three-way catalyst is used to convert HC, CO2, and NOx into less harmful gases. True or False

False

A gear ratio of less than 1:1 is called: -Gear reduction -Overdrive -Direct drive -None of the above

Gear reduction

All of the following situations may call for timing advance except: -Higher engine speed -Heavy engine load -Engine warmup -Constant speed and load

Heavy engine load

An IAC valve stuck in the closed position may cause all of the following except: -Stalling. -Rough idle. -High idle speed. -Low idle speed.

High idle speed.

Which of these operating conditions require the cooling fan to come on? -Highway speeds -Low speeds and idle -Deceleration or coasting -All of the above

Low speeds and idle

The purpose of the manifold vacuum connection to the fuel pressure regulator is to: -Enrich the air/fuel ratio under wide open throttle conditions -Maintain the same pressure drop across the injectors at idle speed and wide-open throttle -Decreases the amount of fuel delivered during idle -conditions -Both A and C

Maintain the same pressure drop across the injectors at idle speed and wide-open throttle

All are functions of the modern fuel system except: -Filter the fuel entering the engine -Store fuel until needed -Atomize the fuel -Mix the fuel with the air

Mix the fuel with the air

All of the following are responsible for air entering the combustion chamber except: -The venturi principle -Momentum -Atmospheric pressure -Vacuum

Momentum

While discussing the diagnosis of an EI system, Technician A says the primary coil normally has between 5,000 and 20,000 ohms of resistance. Technician B says the coil secondary normally has less than 2 ohms of resistance. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Neither A nor B

The EGR valve is used to reduce: -Hydrocarbons -Carbon monoxide -Carbon dioxide -Oxides of nitrogen

Oxides of nitrogen

To help isolate a clogged or dirty injector: -Check the resistance of each injector. -Use a noid light to check for a signal from the -computer. -Perform an injector balance test. -Both A and C

Perform an injector balance test.

High voltage is induced in the coil's secondary windings when the ____________________ magnetic field ____________________.

Primary, collapses

The catalytic converter ____________________ and ____________________ the exhaust emissions from the engine.

Reduces, oxidizes

Which of the following will cause diagnostic codes to set? -Leaner than normal -Richer than normal -Remain 14.7:1 -None of the above

Richer than normal

Pulse width is normally measured in: -Milliseconds -Duty cycle -Seconds -Thousands of seconds

Seconds

In an ion sensing ignition system, information about the combustion chamber is determined by the: -Crankshaft position (CKP) sensor -Camshaft position (CMP) sensor -Knock (KS) sensor -Spark plug

Spark plug

The raster pattern on an oscilloscope displays cylinder patterns: -With all of the cylinders in a row from left to right. -Superimposed with one on top of the other. -One cylinder at a time. -Stacked one above the other.

Stacked one above the other.

As a battery discharges: -Sulfuric acid joins with lead -Oxygen separates from hydrogen -The electrolyte contains very little oxygen -none of the above

Sulfuric acid joins with lead

Ford's EI systems are being discussed: Technician A says the CKP sensor is a variable reluctance sensor. Technician B says the system uses a separate ignition module. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Technician A

Technician A says GDI (Gasoline Direct Injection) systems operate under very high pressures. Technician B says GDI (Gasoline Direct Injection) systems are no longer used in modern engines. -Technician A -Technician B -Both -Neither

Technician A

Technician A says a speed density EFI system is one in which the computer calculates the amount of air entering the engine. Technician B says that to determine the air entering the engine in a speed-density system, the computer uses the TPS and ECT signals. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Technician A

Technician A says higher fuel pressure at wide-open throttle is the result of low manifold vacuum to the pressure regulator in the SFI system. Technician B says higher fuel pressure at wide-open throttle is maintained by the PCM in the SFI system to enrich the air/fuel ratio for better acceleration. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Technician A

Technician A says if the firing voltage is higher than normal the burn time will decrease. Technician B says if the firing voltage is lower than normal the burn time will decrease. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Technician A

Technician A says the poppet nozzles in the CMFI system are opened by fuel pressure. Technician B says the computer opens the poppet nozzles in the CMFI system. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Technician A

Technician A says variable valve timing engines use more valve overlap at idle speeds. Technician B says manufactures use only an actuator on the exhaust camshaft for variable valve timing. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Technician A

Technician A says you should never connect or disconnect the battery charger cables from the battery terminals with the charger in operation. Technician B says when disconnecting a battery the first disconnection should be the positive battery cable. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Technician A

While discussing fuel injection testing, Technician A says that power and ground to the injectors can be tested with a noid light. Technician B says a test light can also be used to test for power and ground at the injector. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Technician A

While discussing the testing of a Hall-effect switch, Technician A says that the Hall-effect switch should read zero volts with the feeler gauge inserted between the hall layer and the magnet with battery voltage applied. Technician B says that the Hall-effect switch can only be tested with a scan tool. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Technician A

Spark plugs are being discussed: Technician A says iridium spark plugs should not have the gap checked by the technician. Technician B says platinum spark plugs should not have the electrode filed. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Technician B

Technician A says a Zener diode breaks down at a specific voltage and will block current flow in both directions. Technician B says a Zener diode breaks down at a specific voltage and allows current to flow in either direction. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Technician B

Technician A says a defective starter is a likely cause of low cranking speed and low current draw. Technician B says resistance in the starter circuit may result in low cranking speed and low current draw. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Technician B

Technician A says coolant is routed through the throttle body to warm the incoming air. Technician B says the throttle body is warmed by coolant to prevent it from freezing. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Technician B

Technician A says current flows through the battery and electrical accessories on the vehicle from the alternator battery terminal. Technician B says AC voltage in the stator windings is induced by the rotor magnetic field. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Technician B

Technician A says that if the spark plug wire terminal ends are not clean and tight, the terminals should be cleaned and recrimped. Technician B says the spark plug wires need to be replaced. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Technician B

Technician A says the ignition timing must retard as RPM increases. Technician B says ignition timing is retarded under maximum load. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Technician B

While discussing direct fuel injection (DFI), Technician A says the DFI injector may require a special tool to remove it from the cylinder head. Technician B says the DFI high-pressure fuel line from the high-pressure pump to the fuel rail can be reused only twice before replacement. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Technician B

While discussing throttle actuator control (TAC), Technician A says some technicians call these systems "throttle by wire". Technician B says that TAC systems have idle air control (IAC) systems that need to be adjusted periodically. Who is correct? -Technician A -Technician B -Both A and B -Neither A nor B

Technician B

The ignition switch, primary coil winding, and module are all components of: -The distributor. -The secondary ignition circuit. -The Hall-effect switch. -The primary ignition circuit.

The primary ignition circuit.

The component that permits fast warmup of the engine after it has been started is the: -Radiator -Water pump -Thermostat -Radiator cap

Thermostat

Which of the following is false concerning variable valve timing engines? -They use the crankshaft actuator to change valve timing. -They utilize a PCM controlled solenoid that operates an actuator. -They utilize the camshaft (CMP) and crankshaft (CKP) sensors to determine the amount of advance or retard. -Owners need to pay particular attention to the oil level and condition.

They use the crankshaft actuator to change valve timing.

A bent fan blade should be straightened. True or False

True

A defective radiator cap may cause the upper radiator hose to collapse when the coolant is cold. True or False

True

Cold engines require more power to crank over and start than warm engines. True or False

True

Detonation may be caused by excessive ignition spark advance. True or False

True

In a parallel circuit the total resistance is less than the value of any resistor in the circuit. True or False

True

One complete combustion cycle requires two revolutions of the crankshaft. -True -False

True

The combustion chamber is the space between the top of the piston and the cylinder head. True or False

True

The fuel pressure regulator in a returnless fuel system is located: -With the fuel pump module -On the fuel rail. -Between the fuel filter and the fuel rail. -On the engine block.

With the fuel pump module

Barometric pressure of 14.7 psi is equivalent to: -1 bar -1 atmosphere -100 kPa -All of the above

all of the above

The intake manifold tuning valve makes the intake manifold: -an active manifold. -respond to driver demands. -increase performance. -all of the above

all of the above

The ____________________ system carries heat away from the cylinders to be dissipated by the radiator.

cooling

Base timing is the initial timing specified by the: -engine size. -manufacturer. -engine load. -firing order.

manufacturer.

A fuel system with the fuel pressure regulator at the fuel pump in the fuel tank is called a ____________________ system.

return-less