Engine Performance Final

Which of the following fuel systems can have fuel pressure of over 1500 psi?

DFI

The __________ informs the driver that a fault that affects the vehicle's emission levels has occurred.

MIL

The sensor signal that alerts the misfire monitor that a misfire may be occurring is provided by the:

The crankshaft position sensor.

Which statement is true about companion cylinders:

When one cylinder is on the exhaust stroke the other is on the compression stroke.

The amount of time the coil is turned on is called _____

dwell

On a COP equipped engine, if the crankshaft position sensor signal circuit becomes opened: -A- The ignition coils will not fire the spark plugs. -B- The fuel injectors will not pulse. -C- Engine rpm will not display on a scan tool. -D- All of the above

All of the above.

Higher-than-normal fuel pressure may be caused by:

Both A and B A defective fuel pressure regulator. A fuel return line that is restricted.

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

______ is the precise position of the piston at the top of its travel in the cylinder.

TDC

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.

Technician A

The output voltage of a downstream O2 sensor is fluctuating (same as the upstream O2 sensor) when the engine is at operating temperature. Technician A says the catalytic converter is working efficiently. Technician B says the O2 sensor may need to be replaced.

Neither A nor B

The fuel pressure regulator in a returnless fuel system is located:

With the fuel pump module.

Low-side drivers apply _____ to a circuit.

ground

For maximum engine power to be obtained, maximum cylinder pressure should occur:

10 - 20 ATDC

If a technician uses a scan tool to open the EGR valve while the engine is at idle: -A- The engine will idle rough. -B-The technician may be able to see the results of the command using the scan tool. -C-An EGR system DTC may set. -D- Both A and B

Both A and B

Technician A says a fuel rail holds all the injectors on a PFI equipped engines. Technician B says a PFI fuel injection system sprays fuel into the intake port near the intake valve.

Both A and B

Multiport fuel injection systems do not require a:

Camshaft position sensor

A pending code is one that:

Has had one failure but has not had a second consecutive failure.

Injector pulse width is:

The amount of time the injector is held open and injecting fuel.

E-85 is a mixture ____ of percent ethanol and _____ percent gasoline.

85, 15

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.

Both A and B

The firing voltages of a four cylinder engine are as follows: #1: 8kV; #2: 27kV; #3: 8kV; and #4: 9kV. Which of the following statements is true?

Cylinder #2 may have an open spark plug wire.

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.

Technician A

Technician A says the fuel rail delivers fuel to the fuel injectors. Technician B says the throttle body in a port fuel injection system controls the amount of fuel entering the engine.

Technician A

Technician A says the powertrain control module (PCM) provides the proper air-fuel ratio by controlling injector pulse width. Technician B says the powertrain control module (PCM) controls the fuel pressure to provide the proper air-fuel ratio.

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.

Technician A

The ignition switch, ignition coil primary winding, and igntion control module are all components of:

The primary ignition circuit.

The acceptable amount of alcohol mixed with gasoline (non E-85) is:

Up to 10 percent.

An octane number is a measure of a gasoline's _____ quality.

antiknock

For the __________(two words) to work efficiently, the air-fuel ratio must be maintained very close to 14.7:1.

catalytic converter

EI systems that do not use spark plug wires are called_______ systems.

coil on plug

The three sections of an ignition secondary pattern are ______ section, _____ section, and ________ section.

firing. intermediate. dwell

Increasing an injectors on time ________ the amount of fuel delivered to the cylinders.

increases

Spark duration (burn time) is measured in_______

milliseconds

Catalytic converter efficiency is measured by monitoring the ______ capacity of the converter during closed loop operation.

oxygen storage

The ignition coil works on the principle of magnetic induction to change 12 volts in the_________ circuit to 40,000 volts in the ___________ circuit.

primary, secondary

In both MFI and SFI systems, the computer supplies the correct _________ signal to the fuel injectors based off fuel trim adjustments.

pulse-width modulation

A fuel injector is actually a _______

solenoid

Ignition control modules (ICMs) control:

The ground circuit to the primary coil winding.

The fuel pressure regulator in return-type fuel systems is located:

At the outlet of the fuel rail.

Technician A says lower than normal fuel pressure may be caused by a restricted fuel filter. Technician B says when testing fuel pressure make sure the specifications are either for the engine running or the engine off. Who is correct?

Both A and B

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

Octane is use to reduce:

Detonation.

An IAC valve stuck in the closed position may cause all of the following except:

High idle speed.

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.

Technician A

How many times can a direct fuel injection high-pressure pump to fuel rail line be reused?

0

Which of the following could cause a weak spark condition? -A-High resistance on the ground side of the ignition module. -B-Primary coil winding resistance of 50 ohms. -C-High resistance in the ignition coil power feed circuit. -D- All of the above

All of the above.

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.

Both A and B

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 enrichen the air/fuel ratio for better acceleration.

Both A and B

Technician A says long term fuel trim works to bring short term fuel trim close to zero percent correction. Technician B says if a lean condition exists over a period of time because of a vacuum leak, the long term fuel trim will have a plus (+) number on the scan tool.

Both A and B

Technician A says one component of the secondary ignition circuit is the ignition coil. Technician B says the ignition coil is a component in the primary ignition circuit.

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.

Both A and B

Technician A says to relieve pressure on an PFI (port fuel injection) system, a pressure gauge may be connected to the fuel pressure test port and the bleed (pressure relief) valve on the gauge opened with the bleed hose installed in an approved container. Technician B says before fuel system components on an PFI system can be removed, the fuel system pressure must be relieved.

Both A and B

The MIL of an OBD-equipped vehicle is flashing. Technician A says a spark plug wire may be shorted to ground. Technician B says a cylinder may have low compression.

Both A and B

Which of the following is not part of comprehensive component monitoring?

Catalyst efficiency

The time during which current flows through the primary coil winding is called:

Dwell

Which of the following is not part of the primary circuit?

High tension leads

The switching device in the ignition system is sometimes referred to as a(n):

Ignition control module.

When the pressure in the intake manifold increases, the fuel pressure regulator on a port fuel injection system:

Increases fuel pressure.

With direct fuel injection (DFI), the gasoline is injected:

Into the combustion chamber.

All of the following are PCM actuators excep

PCV valve

Which type of fuel injector has a relatively high current applied to quickly open the pintle, then the current is reduced to lower level.

Peak and hold injectors

To help isolate a clogged or dirty injector:

Perform an injector balance test.

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.

Technician A

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.

Technician B

Technician A says enabling criteria defines the criteria that must be met before the vehicle will enter closed loop. Technician B says enabling criteria defines the criteria that must be met in order for a monitor test to be completed.

Technician B

Technician A says reducing spark advance can cause spark knock (detonation). Technician B says excessive carbon deposits in the combustion chamber can cause spark knock (detonation).

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.

Technician B

Technician A says the ignition timing must be fully advanced when the engine is operating at maximum load. Technician B says ignition timing is retarded under maximum load.

Technician B

Two technicians are discussing a flashing MIL. Technician A says it indicates a fuel system malfunction that may damage the O2 sensor. Technician B says it indicates a misfire that may damage the catalytic converter.

Technician B

Bi-directional control means:

The technician can tell a computer to exercise an output

Direct fuel injection systems use conventional electric fuel pump along with a __________ (two words) fuel pump.

high pressure

The inertia switch is located in the ______on most Ford passenger cars.

trunk