Engine Perf. Chap. Quizzes
The fuel pressure regulator in a returnless fuel system is located:
At the fuel pump sender assembly
Technician A says pulse width modulation is the duration of on time, but not connected to a specific cycle time. Technician B says duty cycle is measured in percentages. Who is correct?
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?
Both A and B
The purpose of the PCV system is to:
All of the above
Turbo lag may be referred to as:
All of the above
Which of the following may contribute to detonation?
All of the above
Which of the following will cause diagnostic codes to set?
All of the above
A turbocharger:
Compresses intake air
The result of a plugged catalytic converter can cause an exhaust restriction which in turn will cause:
Both B and C
The evaporative system reduces:
Hydrocarbons
Air injection reaction systems are used to reduce:
Hyrdocarbons
All of the following are the same communication protocol except:
ISO 9141
The acceptable amount of alcohol mixed with gasoline is:
up to 10 percent.
Which of the following is a pre-combustion emission control?
EVAP
A bent fan blade should be straightened.
False
The EGR valve is used to reduce hydrocarbon emissions.
False`
A gear ratio greater than 1:1 is called:
Gear reduction
In the PCV system, crankcase vapors are recycled to the:
Intake manifold
A partially restricted or blocked exhaust system may result in:
Loss of engine power
Which of these operating conditions require the cooling fan to come on?
Low speeds and idle
An EGR DPFE is most similar in operation to a:
MAP sensor
All are functions of the modern fuel system except:
Mix the fuel with the air
All of the following are responsible for air entering the combustion chamber except:
Momentum
During cold engine start or acceleration, the air-fuel mixture may be:
Richer than normal
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 B
The supercharger is driven by:
The crankshaft
Magnetic pulse generators are commonly used to send data to the computer about:
The speed of the monitored component
What type of noise will be caused by a piston slap?
A hollow, rapping noise that is most noticeable on acceleration when the engine is cold.
A low voltage signal from the O2 sensor indicates:
A lean air/fuel ratio
All of the following may increase CO except:
A restricted fuel filter.
Black smoke from the exhaust is caused by:
A rich air/fuel ratio
In a CAN network, if a module fails to "check in" with the other modules:
A trouble code is set
A defective PCV valve can cause:
All of the above
An air filter that is contaminated with oil may be caused by:
Both A and B
Technician A says that if the EGR is open at idle and low speeds, the engine may stall on deceleration. Technician B says that if the EGR is open at idle and low speeds, the engine may surge during low-speed operation. Who is correct?
Both A and B
Technician A says that if the engine rpm is constant, the scan tool should show a constant MAF grams-per-second reading. Technician B says the MAF sensor is a frequency producing sensor. Who is correct?
Both A and B
Technician A says the computer may activate a circuit by completing the path to ground. Technician B says the computer may activate a circuit by completing the path to power. Who is correct?
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?
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?
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?
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?
Both A and B
Technician A says the relationship of the change of pressure and altitude is inversely proportional. Technician B says atmospheric pressure decreases as altitude increases. Who is correct?
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?
Both A and B
After 2008 the only communication standard that can be used is
CAN
When using a five gas analyzer on an engine with a lean air/fuel ratio:
CO readings will be lower than normal and O2 readings will be higher than normal
The EGR valve is used to reduce:
Oxides of nitrogen
All of the following are PCM actuators except:
PCV valve
Which type of fuel injector has a relatively high current applied to quickly open the pintle, and then the current is reduced to lower level.
Peak and hold injectors
A clutch pedal position sensor (CPP) sensor is being discussed: Technician A says that the CPP sensor tells the ECM if the clutch is engaged or disengaged. Technician B says a defective CPP sensor also affects MAF sensor calculations. Who is correct?
Technician A
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 A says CAN network modules can share information with other modules on the same bus. Technician B says the CAN class A bus is for high speed data. Who is correct?
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
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
While discussing EVAP valves, Technician A says the evaporative emissions system has to be able to detect a leak as small as 0.010" in size. Technician B says that the monitor for the EVAP system works by closing the vacuum and vent valves and watching to see if the tank pressure drops. Who is correct?
Technician B
While discussing the Ford Electronic Automatic Temperature Control Module system Technician A says: The Ford Electronic Automatic Temperature Control Module is completely responsible for operating the air conditioning system. Technician B says: The PCM has the last word on whether the air conditioning system will be allowed to operate. Who is correct?
Technician B
All of the following are added to gasoline except?
Tetraethyl lead
The OBD II AIR system pumps air into
The Exhaust manifold.
A defective crankshaft position sensor is a common cause of a no-start condition.
True
Base timing is the initial timing specified by the:
manufacturer.
Piezoresistive sensors measure:
pressure and mechanical strain.
Excessive oxygen in the exhaust gas stream will cause a zirconia oxygen sensor to:
stay below 450mv
For work to have taken place, a mass can be:
Both A and B
Fuel line service is being discussed. Technician A says that copper is an acceptable material for replacement lines. Technician B says a double flare fitting should be used. Who is correct?
Both A and B
High fuel pressure may be caused by:
Both A and B
If a technician uses a scan tool to open the EGR valve while the engine is at idle:
Both A and B
Knock sensors are being discussed: Technician A says the first thing to check is the systems wiring and connections for corrosion or looseness. Technician B says the knock sensor has one purpose, to control spark knock. Who is correct?
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?
Both A and B
Technician A says a quad driver has four independently controllable outputs. Technician B says some output driver modules may control up seven independent outputs. Who is correct?
Both A and B
Technician A says any induction air leak after the MAF sensor can cause a poor running condition. Technician B says an air leak after the MAF sensor results in un-metered air. Who is correct?
Both A and B
Technician A says each module in a CAN system receives every communication on the serial data bus. Technician B says only the messages with the correct heading are responded to by a module in a CAN system.
Both A and B
Technician A says fuel that has low volatility can cause a buildup of deposits in the combustion chamber. Technician B says liquid gasoline will not burn. Who is correct?
Both A and B
Technician A says if a timing belt or chain becomes excessively worn, it is possible that a change in valve timing accuracy will result. Technician B says an excessively worn timing chain or belt can cause the timing to jump. Who is correct?
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?
Both A and B
Technician A says low fuel pressure may be caused by a restricted fuel filter. Technician B says when testing fuel pressure to make sure the specifications are either for the engine running or the engine off. Who is correct?
Both A and B
Technician A says oil accumulation in the air cleaner may indicate the PCV valve or hose is restricted. Technician B says a restricted PCV valve or hose may result in the accumulation of moisture and sludge in the engine and engine oil. Who is correct?
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?
Both A and B
Technician A says placing the turbocharger close to the exhaust helps its efficiency. Technician B says the turbocharger shaft may turn at speeds in excess of 100,000 rpm. Who is correct?
Both A and B
Technician A says that compression can be raised by physically modifying the engine. Technician B says that compression can be effectively raised by using a turbocharger to force air into the engine. Who is correct?
Both A and B
Technician A says to relieve pressure on an EFI system, a pressure gauge may be connected to the fuel pressure test port and the bleed valve on the gauge opened with the bleed hose installed in an approved container. Technician B says before fuel system components on an EFI system can be removed, the fuel system pressure must be relieved. Who is correct?
Both A and B
The boiling point of the coolant in the engine may be increased by:
Both A and B
The catalytic converter may be tested with:
Both A and B
The computer uses the TP sensor input to:
Both A and B
The vent valve in an evaporative emissions system may be:
Both A and B
Bi-directional control means:
The technician can tell a computer to exercise an output
Brake horsepower may be defined as
The useable power at the engine's crankshaft
The component that permits fast warmup of the engine after it has been started is the:
Thermostat
Which of the following is false concerning variable valve timing engines?
They use the crankshaft actuator to change valve timing.
Twenty inches of vacuum would be equivalent to how much pressure absolute?
5 psia
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
At 2,000 rpm, the maximum allowable exhaust back pressure is approximately:
1.2 psi
Approximately how much of an engine's energy is used to drive the vehicle?
15%
50 pounds applied to a wrench 36 inches long will produce how much torque:
150 ft lbs
Oxides of nitrogen (NOx) are formed when combustion temperatures reach more than:
2,500 degrees F.
A defective engine coolant temperature may cause:
All of the above
An electronic engine control system consists of:
All of the above
Barometric pressure of 14.7 psi is equivalent to:
All of the above
Variable cam timing is used to:
Allow high duration at high rpm
While discussing J2534 pass-through programming: Technician A says that before programming a module, make certain that the battery voltage is at least 12.5 volts. Technician B says that after a module is programmed, there may be additional steps to set up the module, such as setting tire size. Who is correct?
Both A and B
Oil is found in the air filter housing. Which of the following conditions could be the cause?
Both A and C
Converting mechanical energy into heat energy is accomplished by the:
Brake system
Which exhaust gas is near its highest level when the air/fuel ratio is near stoichiometric?
CO2
Multiport fuel injection systems do not require a:
Camshaft position sensor
Compression sense ignition allows for the elimination of the:
Camshaft sensor
Diesel fuel may be blended to improve:
Cold starting
The front passenger door module is a slave module which can:
Communicate with other modules on the main serial bus
An intercooler is used to:
Cool the air from a supercharger or turbocharger before it reaches the combustion chamber.
Which of the following fuel systems can have fuel pressure of over 1500 psi?
DFI
An Atkinson cycle engine uses variable valve timing to:
Decrease compression
Octane is use to reduce:
Detonation
UART, J1850 and KWP 2000 are:
Different computer networking languages.
The components of the PCM responsible for controlling circuits or devices are called:
Drivers
An automotive battery converts chemical energy into:
Electrical energy
The starter motor converts:
Electrical energy into mechanical energy
Higher than normal reference voltage is recorded at a sensor. Which is the most likely cause?
Excessive resistance in the voltage reference ground circuit.
The measurement of the rate at which work is performed is measured in:
Horsepower
A defective O2 sensor heater may cause reduced open loop time.
False
A four cycle engine takes two complete camshaft revolutions and one revolution of the crankshaft to complete one engine cycle, firing all cylinders once.
False
A type A DTC will set a pending code on the first failure and the MIL is illuminated on the second consecutive failure.
False
A vehicle with throttle actuator control typically uses three throttle position sensors.
False
An oxidation catalyst may be referred to as a three way catalyst.
False
Base or initial timing is timing with computer advance added.
False
Central multiport fuel injection systems use poppet valves that are located in the fuel meter assembly.
False
Direct gasoline injection systems spray fuel directly into the combustion chamber when the intake valve is opened.
False
Engines that have throttle actuator control require an idle air control motor.
False
Fuel system pressure should be relieved with the engine running.
False
High oxygen levels are a good indicator of a rich air-fuel ratio.
False
If dwell time is to short, the coil and module can overheat.
False
Magnetic pulse generators are used to provide a digital signal about component speed or position.
False
Modules on the serial bus that can initiate communication with other modules on the serial data bus are called slaves.
False
Nearly all OBD II vehicles provide the ability to obtain flash codes for diagnostics.
False
Oils with a higher viscosity rating should be used in colder temperatures.
False
On all modern engines, the crankshaft, camshaft, and valves are located within the engine block.
False
On many vehicles the fuel pump is directly powered by the PCM.
False
Pressure and temperature are inversely proportional to each other.
False
Surging at low speeds or a rough idle may occur if the EGR valve is stuck closed.
False
The American Petroleum Institute (API) is a technical society that has established a classification system that standardizes oil viscosity ratings.
False
The idle air control motor works by varying the position of the throttle plate.
False
The mass air flow sensor is located in the intake manifold
False
The piston converts reciprocating motion into rotary motion.
False
The third digit of a DTC indicates whether the code is an SAE or manufacturer-specific code.
False
The three-way catalyst is used to convert HC, CO2, and NOx into less harmful gases.
False
Turbochargers and superchargers force more fuel into the cylinders to increase performance.
False
When checking a solenoid with an ohmmeter, there should be an infinity reading on the meter if the solenoid is good.
False
When the engine is at operating temperature, a NTC (Negative Temperature Coefficient) engine coolant temperature sensor resistance is high.
False
All of the following components are is responsible for creating engine vacuum, except?
Fuel Injector
During an IM240 emissions test the exhaust gasses are measured in:
Grams per mile
The OBD II EVAP system is designed to reduce which emission?
HC
The three major automotive pollutants are:
HC, CO, and NOx
Oxides of nitrogen (NOx) are caused by:
High cylinder temperature
If the pressure is increased on a gas in an enclosed container, the temperature of the gas will:
Increase
When the pressure in the intake manifold increases the fuel pressure regulator on a port fuel injection system:
Increases fuel pressure
The computer may use the manifold absolute pressure sensor to monitor all of the following except:
Intake manifold air flow
With direct fuel injection the gasoline is injected:
Into the combustion chamber
A breakout box is used to:
Monitor signals received by the computer.
Which exhaust gas /gasses are controlled by the EGR valve?
NOx
A three-way catalyst is named for its ability to reduce which emissions:
NOx, CO, HC
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?
Neither A nor B
Technician A says an open in star network bus will affect all the modules on the network. Technician B says an open in a loop network will isolate a module from the network.
Neither A or B
Technician A says fuel injectors may be cleaned by soaking them in solvent. Technician B says it is a good idea to use a wire brush to unclog injectors. Who is correct?
Neither A or B
Technician A says that air-fuel ratio (AF) sensors can be diagnosed with a voltmeter. Technician B says the AF sensor is a Hall Effect sensor. Who is correct?
Neither A or B
Technician A says that the intake air temperature (IAT) sensor is a voltage-generating sensor. Technician B says the MAF sensor is a voltage reference sensor. Who is correct?
Neither A or B
Which of the following is not an advantage of the stratified charge engine?
Requires high octane fuel
The __________ of the heated wire in a hot-wire Mass Air Flow (MAF) sensor changes depending on airflow.
Resistance
Excessive CO emissions may be caused by:
Rich air-fuel mixtures.
Which of the following can be used to locate both exhaust and vacuum leaks?
Smoke
Which of the following emissions are specific to diesel engines?
Soot
The raster pattern on an oscilloscope displays cylinder patterns:
Stacked one above the other.
Modules that are not part of any vehicle network are called:
Stand alone modules
All of these are classifications of hybrid designs except:
Strong
All of the following are true about supercharging EXCEPT:
Superchargers are driven by the exhaust flow.
Technician A says a fuel level sensor malfunction may cause a trouble code to set. Technician B says the evaporative emissions check test is only run when the fuel tank is empty. Who is correct?
Technician A
Technician A says a parallel hybrid vehicle uses both the electric motor and the gasoline engine to directly power the drive wheels. Technician B says that the series hybrid uses just the gasoline engine to power the drive wheels, and the battery is used to power accessories.
Technician A
Technician A says a rich air-fuel mixture may be the result of higher-than-normal fuel pressure. Technician B says higher-than-normal fuel pressure causes a lean air-fuel ratio. Who is correct?
Technician A
Technician A says fuel pumps can be checked for amperage draw and current waveform. Technician B says a low amp probe is connected in series with the circuit being tested. Who is correct?
Technician A
Technician A says the computer monitors the operation of the catalytic converter by looking at the upstream and downstream oxygen sensors. Technician B says that a vacuum gauge installed on a manifold vacuum source will rise steadily on hard acceleration if the exhaust is restricted. Who is correct?
Technician A
Technician A says the exhaust gas from the cylinders of a turbocharged engine is directed past the turbine wheel. Technician B says the exhaust gas from the cylinders of a turbocharged engine is directed past the compressor wheel. Who is correct?
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 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
All of the following are true about Hall-Effect TP sensors, except:
The sensor is adjustable
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
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
Which of these statements about modern mass air flow sensors is true?
The sensor produces a digital signal.
Spark plugs are being discussed: Technician A says iridium spark plugs should not have
Technician B
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 B
Technician A says a diagnostic code (DTC) tells the technician exactly which part to replace. Technician B says that OBD II vehicles require the use of a scan tool to read diagnostic codes. Who is correct?
Technician B
Technician A says both the fuel injector and spark plug are turned off when a cylinder is deactivated on a variable displacement engine. Technician B says the spark plug may foul if is allowed to become too cool during cylinder deactivation. Who is correct?
Technician B
Technician A says both turbochargers and superchargers force more fuel into the engine for greater performance. Technician B says engines with turbochargers or superchargers require high octane fuel. Who is correct?
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 B
Technician A says in an ideal combustion process, only HC and O2 would remain. Technician B says internal combustion engines do not achieve complete combustion. Who is correct?
Technician B
Technician A says reducing spark advance can cause spark knock. Technician B says excessive carbon deposits can cause spark knock. Who is correct?
Technician B
Technician A says that if the engine stalls and the ignition switch is on, the one-way check valve prevents fuel flow from the pump to the fuel filter and fuel system. Technician B says that when the engine is shut off, the one-way check valve prevents fuel flow from the underhood fuel system components into the fuel pump and tank. Who is correct?
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 B
Technician A says the DFI fuel injector runs at lower fuel pressures than port fuel injectors. Technician B says that the DFI fuel injector may be difficult to remove from the cylinder head. Who is correct?
Technician B
The ignition switch, primary coil winding, and module are all components of:
The primary ignition circuit.
A defective vehicle speed sensor may cause improper torque converter lockup.
True
A digital signal may be called a square-wave signal.
True
A muffler is a component installed in the exhaust system to reduce or eliminate the engine's post combustion noise.
True
A typical pressure gauge will read atmospheric pressure as zero.
True
After changing motor oil on a turbocharged engine the technician should run the engine at idle for 3-5 minutes to prevent oil starvation to the turbo.
True
An advantage of remotely mounted air filters is increased aerodynamic body design.
True
An ignition system misfire may result in high hydrocarbon readings.
True
An infrared analyzer may be used to test the efficiency of the catalytic converter.
True
An oscilloscope can be used to monitor the injector pulse width.
True
Bluish-white exhaust indicates that there are excessive amounts of oil entering the combustion chamber.
True
Cold engines require more power to crank over and start than warm engines.
True
Enable criteria must be met in order for the PCM to run a system monitor.
True
Energy can be changed into another form but cannot be created or destroyed.
True
If gasoline is allowed to evaporate into the air it becomes a significant source of hydrocarbon emissions.
True
Inertia switches open the fuel pump circuit in case of a severe impact.
True
Many modules have to be reprogrammed for the vehicle if they are to be replaced.
True
Networking smaller more specialized modules is more cost effective than using one or two centralized complex modules.
True
OBD II systems note the deterioration of certain components before they fail.
True
One complete combustion cycle requires two revolutions of the crankshaft.
True
The IM240 test requires the use of a chassis dynamometer and an emissions tester.
True
The OBD II AIR system is meant only to operate long enough to warm the exhaust and help promote catalytic converter light-off by burning left-over HC and CO in the exhaust manifold of a cold engine.
True
The PCV valve helps eliminate water and unburned fuel from the engine.
True
The bore of a cylinder is the diameter measured in inches or millimeters.
True
The combustion chamber is the space between the top of the piston and the cylinder head.
True
The digital EGR is comprised of three solenoids that all flow different amounts of EGR.
True
The ignition coil is both a primary and secondary ignition component.
True
The individual modules in a CAN system are sometimes called nodes.
True
The manifold absolute pressure (MAP) sensor monitors engine load.
True
The octane number indicates the antiknock quality of gasoline.
True
The turbocharger wastegate may be controlled by manifold pressure.
True
Vacuum is described as a lack of pressure.
True
Vapor lock is the evaporation of fuel in the fuel system.
True
When a small gear is driving a large gear, gear reduction is taking place.
True
The period of time that the exhaust and intake valves are both open is called:
Valve overlap
The principle that describes using a restriction to increase the speed of a liquid or a gas is called:
Venturi principle
Which is not a component of the starting system?
Voltage regulator
Glow plugs are used in diesel engines to:
Warm the combustion chamber
Fresh air is allowed to enter the charcoal canister:
When the PCM purges the canister
Which of the following is not an advantage of natural gas fueled vehicles?
Wide availability of CNG
The type of oxygen sensor that changes current flow to indicate exhaust oxygen content is the:
air-fuel ratio sensor
The Ford lighting control module takes care of:
all of the above
Excessive HC emissions may be caused by all of these, except:
an EGR valve stuck open.
