Advanced Engine Performance
An oxygen sensor switch time from rich to lean is identified as test identification (TID)______?
$02
The hexadecimal number for 12 is ____
$A
An oxygen sensor is being tested using a digital storage oscilloscope. A good oxygen sensor should display how many switches per second?
1 to 5
A wide-band oxygen sensor needs to be heated to what operating temperature?
1,400F
If the air-fuel rations is 14.7:1, what is lambda?
1.0
A wide-band oxygen sensor is capable of detecting the air-fuel mixture in the exhaust from _____(rich) to ____(lean)
10:1 to 23:1
The throttle plate is spring loaded to hold the throttle slightly open how far?
16 to 20%
A wide-band oxygen sensor was first used on a Honda in what model year?
1992
At about what temperature does oxygen combine with the nitrogen in the air to form NOx?
2,500F
The air at high altitude has ______.
21% oxygen
Type A misfire codes are those that can damage the catalytic converter and usually have misfires that range from ____ at idle to ____ at high engine speeds.
40%, 4%
The fuel pump inside the fuel tank on a vehicle equipped with GDI produces about what fuel pressure?
50 to 60 PSI
The fuel injectors used on a GDI system are pulsed on using what voltage?
50 to 90 V
The fuel injectors operate under a fuel pressure of about______.
500 to 2,900 PSI
A wide-band oxygen sensor heater could draw how much current (amps)?
8 to 10 A
Most port fuel-injected engines operate on how much fuel pressure?
9 to 13 PSI
A green wrench symbol is displayed on the dash. What does this mean?
A fault in the ETC in a Ford has been detected
A clogged EGR passage could case excessive ______ exhaust emissions?
NOx
When the exhaust is rich, the PCM applies a ____ current into the pump cell.
Negative
Which fuel-injection system uses the MAP sensor as the primary sensor to determine the base pulse width?
Speed density
If the throttle plate needs to be cleaned, what symptoms will be present regarding operation of the engine?
Stalls Rough idle Hesitation on acceleration
What type of device is used in a typical idle air control?
Stepper motor
Which mode of operation results in a richer air-fuel mixture near the spark plug?
Stratified
Which sensor has the greatest influence on injector pulse width besides the MAF sensor?
TP
What is global (generic) OBD II?
A standardized format that meets SAE standard J1962 A format originally designed for engineers The same for all numbers and models of vehicles
The use of an electronic throttle control system allows the elimination of all except _____
Accelerator pedal
The two internal chambers of a dual-cell wide-band oxygen sensor include
Air reference and diffusion
If lambda is 0.98, this means the ______.
Air-fuel mixture is within 2% of stoichiometric Air-fuel mixture is slightly rich
Mode $06 information can be accessed at?
All of the above
The high-pressure fuel pump pressure is regulated by using ______
An electric pressure-control valve
Fuel injectors can be tested using ______.
An ohmmeter A stethoscope A scope
Where is the fuel-pressure regulator located on a vacuum-biased port fuel-injection system?
At the outlet of the fuel rail
Before an evaporative emission monitor will run, the fuel level must be where?
Between 15% and 85%
A P0133 DTC is being discussed. Tech A says that a defective heater circuit could be the cause. Tech B says that a contaminated sensor could be the cause. Who is correct?
Both Technicians A and B
A P0401 is being discussed. Tech A says that a stuck-closed EGR valve could be the cause. Tech B says that clogged EGR ports could be the cause. Who is correct?
Both Technicians A and B
Fuel-injection service is being discussed. Tech A says that the throttle plate(s) should be cleaned. Tech B says that the fuel rail should be cleaned. Who is correct?
Both Technicians A and B
Tech A says that by looking at the mode $06 data, the technician can determine how close a component or system came to passing the onboard test. Tech B says that the data shown may have to be converted to obtain values that are meaningful to the technician. Who is correct?
Both Technicians A and B
Tech A says that carbon inside the engine can cause excessive NOx to form. Tech B says that excessive NOx could be caused by a cooling system fault causing the engine to operate too hot. Who is correct?
Both Technicians A and B
Tech A says that the fuel-pump relay is usually controlled by the PCM. Tech B says that a TBI Injector squirts fuel above the throttle plate. Who is correct?
Both Technicians A and B
The fuel pressure drops rapidly when the engine is turned off. Tech A says that one or more injectors could be leaking. Tech B says that a defective check valve in the fuel pump could be the cause. Who is correct?
Both Technicians A and B
Two techs are discussing clogged EGR passages. Tech A says clogged EGR passages can cause excessive NOx exhaust emissions. Tech B says that clogged EGR passages can cause the engine to ping (spark knock or detonation). Who is correct?
Both Technicians A and B
Two techs are discussing testing a catalytic converter. Tech A says that a vacuum gauge can be used and observed to see if the vacuum drops with the engine at 2500 RPM for 60 seconds. Tech B says that a pressure gauge can be used to check for backpressure. Who is correct?
Both Technicians A and B
Which gas is generally considered to be the rich indicator? (The higher the level of this gas, the richer the air-fuel mixture.)
CO
Which gas is generally considered to be the lean indicator? (The higher the level of this gas, the more efficient the engine operates.)
CO2
Which EVAP valve(s) is(are) normally closed?
Canister purge valve
A lack of power from an engine equipped with GDI could be to ____
Carbon on the injectors Carbon on the intake valves
The throttle body may be cleaned (if recommended by the vehicle manufacture) if what conditions are occurring?
Coast-down stall Rough idle Lower-than-normal idle speed
Base pulse width is determined by _____
Computer calculations Input from many sensors, except the oxygen sensor
A conventional zirconia oxygen sensor can be made with what designs?
Cup and planar
The throttle plate actuator motor is what type of electric motor?
DC Motor
Where is the fuel injected in an engine equipped with GDI?
Directly into the combustion chamber
A wide-band oxygen sensor can be made using what design?
Dual cell and single cell
Which type of port fuel-injection system uses a fuel-temperature and/or fuel-pressure sensor?
Electronic returnless systems
The actuator motor is controlled by the PCM through what type of circuit?
H-bridge
All of the gases are measure in percentages except _____?
HC
An ignition fault could cause excessive _____ exhaust emissions
HC
What component pulses the fuel injector on most vehicles?
Ignition module Crankshaft sensor
What is NOT true about short-term fuel trim?
It can add and subtract a large amount of fuel
A low O2S voltage could be due to a _______
Lean exhaust Defective spark plug wire
When testing an oxygen sensor using a digital storage oscilloscope, how quickly should the voltage change when either propane is added to the intake stream or a vacuum leak is created?
Less than 100 ms
Injector pulse width is measured in ______
Milliseconds (ms)
Mode $06 is the mode that checks which system?
Noncontinuously monitored systems
The sensor that must be warmed up and functioning before the engine management computer will go to closed loop is the _____
O2S
Where is sensor 1, bank 1 located on a V-type engine?
On the same bank where number 1 cylinder is located In the exhaust system upstream of the catalytic converter
In a speed density system, what does NOT need to be corrected for?
Oxygen in the exhaust system from the oxygen snesor
Port fuel-injection systems generally use what type of injector drive?
Pulse-width modulated
Dampeners are used on some fuel rails to _____
Reduce noise
Why are some fuel rails rectangular in shape?
Reduces noise
The voltage output of a zirconia oxygen sensor when the exhaust stream is lean (excess oxygen) is ____.
Relatively low (close to zero volts)
When removing a high pressure line on a GDI engine, what should the technician do?
Replace the line with a new part
A high O2S voltage could be due to a ______
Rich exhaust
HC and CO are high, and CO2 and O2 are low. This could be caused by a _______
Rich mixture
An EGR valve that is partially stuck open would MOST LIKELY cause what condition?
Rough idle / Stalling
Throttle-body fuel-injection systems use what type of injector drive?
Saturated switch
A dual-cell wide-band oxygen sensor can be tested using a ____
Scan tool Voltmeter Scope
An oxygen sensor is being tested with a DMM using the MIN/MAX function. The readings are min = 78 mV, max = 932 mV, and average = 442 mV. Tech A says that the engine is operating correctly. Tech B says that the oxygen sensor is skewed too rich. Who is correct?
Technician A only
Tech A says that high HC emissions levels are often caused by a fault in the ignition system. Tech B says that high CO2 emissions are usually caused by a richer-than-normal air-fuel mixture. Who is correct?
Technician A only
The switching valves on the AIR pump have failed several times. Tech A says that a defective exhaust check valve could be the cause. Tech B says that a leaking exhaust system at the muffler could be the cause. Who is correct?
Technician A only
How much air flows through the PCV system when the engine is at idle speed?
Up to 30%
A General Motors vehicle is being checked using mode $06 for the proper operation of the oxygen sensor. The rich-to-lean sensor switch time is 0.030 seconds. Tech A says that this indicates a slow reacting oxygen sensor. Tech B says that the oxygen sensor is reacting correctly and is okay. Who is correct?
Technician B only
Tech A says that if a PCV rattles, than it is okay and does not need to be replaced. Tech B says that if a PCV valve does not rattle, it should be replaced. Who is correct?
Technician B only
Tech A says that the port fuel-injection injectors operate using 5 volts from the computer. Tech B says that sequential fuel injectors all use a different wire color on the injectors. Who is correct?
Technician B only
The vacuum hose from the fuel-pressure regulator was removed from the regulator and gasoline dripped out of the hose. Tech A says that this is normal and that everything is okay. Tech B says that one or more of the injectors may be defective, causing the fuel to get into the hose. Who is correct?
Technician B only
The high-pressure fuel pumps used in GDI systems are powered by _____
The Camshaft
A Nissan is being checked, using a scan tool, and Alpha is 107. This means ______
The PCM is adding fuel
In a MAF system, which is correct?
The amount of EGR flow must be subtracted from the MAF sensor reading
Mode $06 can be used to verify a repair by checking ____
The component system test passed
A contaminated or defective MAF sensor is indicated if _____.
The fuel trim number follows the airflow
The data display usually shows what information?
Upper limit or lower limit Test results
A technician is checking the operation of the ETC system by depressing the accelerator pedal with the ignition in the on (run) position (Engine off). What is the most likely result if the system is functioning correctly?
The throttle goes to wide open when the accelerator pedal is depressed all the way
With the ignition off and the key out of the ignition, what should happen if a technician uses a screwdriver and pushes gently on the throttle plate in an attempt to open the valve
The throttle should move and then spring back to the home position when released.
A heated zirconia oxygen sensor will have how many wires
Three Four
Why is a vacuum line attached to a fuel-pressure regulator on many port fuel-injected engines?
To create an equal pressure drop across the injectors
After the following exhaust emissions were measured, how was the engine operating? HC = 766ppm CO2 = 8.2% CO = 4.6% O2 = 0.1%
Too rich
A GDI system can be used to start an engine without the need for a starter.
True
Some engines that use a GDI system also have port injection
True
The throttle position sensor used in the throttle body assembly of an ETC system is what type?
Two potentiometers that read in the opposite direction Hall-effect sensor
When does the PCM perform a self-test of the ETC system?
When the ignition switch is first rotated to the on position before the engine starts