EP1 test #3 ECTC with Mr.Po
All of the following statements are correct EXCEPT .
***Fuel makes contact with the injector windings. Fuel cools the injector. O-rings seal the injector to keep fuel away from the windings. Dirt and water are more likely to contaminate the injectors is the fuel level is low.
All these methods can calculate airflow EXCEPT
***Load calculation Mass airflow Speed density All of these are methods of calculating the air-fuel mixture
All of the following statements are correct EXCEPT .
***Testing an ignition coil for resistance will always indicate its condition Resistance test may not reflect the actual performance conditions of an ignition coil. Current ramping can be used to test for current limits and charging rise time of the ignition circuit A digital storage oscilloscope is used to perform current ramping tests.
Typical primary coil resistance specifications usually range from ___ ohms.
1 to 3
During a fuel injector pressure drop test, the difference between any two fuel injectors should not exceed?
1.5 PSI
Most port fuel-injected engines operate on how much fuel pressure?
35-45 PSI
Which of the following values for IAC count would indicate a vacuum leak on a speed density system?
5 or less
Typical secondary coil resistance specifications usually range from ___ ohms
6,000 to 30,000
A waste-spark-type ignition system )Fires two spark plugs at the same time )Fires one spark plug with reverse polarity )Fires one spark plug with straight polarity )All of these
All of these
On a vehicle with a speed density fuel injection system, which of the following is likely to occur with a vacuum leak? )Increased idle speed )Increase MAP sensor )voltage )Increased calculated load All of these are correct
All of these are correct
All of these are types of injector circuits
All of these are types of injector circuits EXCEPT Saturated switch Peak and hold Pulse width modulated All of these are types of injector circuits
All these are returnless fuel systems
All these are returnless fuel systems EXCEPT Electronic returnless fuel system Mechanical returnless fuel system Demand delivery system All of these are types of returnless systems
Fuel injectors can be tested using
An ohmmeter A stethoscope An oscilloscope *****Any of these
Where is the fuel-pressure regulator located on a vacuum-biased port fuel-injection system?
At the outlet of the fuel rail
The secondary ignition circuit can be tested using
Both An ohmmeter and Visual inspection
Which sensor produces a square wave signal?
Both Hall effect sensor and Optical sensor
Fuel injection service is being discussed. Technician A says that the throttle plate(s) should be cleaned. Technician B says that the fuel rail should be cleaned. Which technician is correct?
Both Technician A and B
Technician A changes the position of a waste-spark ignition coil to diagnose an ignition misfire. Technician B says that a defective coil should cause problems on the cylinders it is connected to. Which technician is correct?
Both Technician A and B
Technician A looks for engine speed (RPM) when cranking an engine that will not start. Technician B says that a problem in the primary circuit could make the tachometer not work. Which technician is correct?
Both Technician A and B
Technician A says defective wires, distributor cap, or ignition coil can often be found by looking for leaking spark while running the engine in the dark. Technician B says a mist of water from a spray bottle can be used to find defective secondary ignition components. Which technician is correct?
Both Technician A and B
Technician A says that a defective crankshaft position sensor can cause a no-spark condition. Technician B says that a faulty ignition control module can cause a no-spark condition. Which technician is correct?
Both Technician A and B
Technician A says that a defective spark plug boot can cause an engine misfire. Technician B says that a tracked ignition coil can cause an engine misfire. Which technician is correct?
Both Technician A and B
Technician A says that a distributor rotor can burn through and cause an engine misfire during acceleration. Technician B says that a defective spark plug wire can cause an engine misfire during acceleration. Which technician is correct?
Both Technician A and B
Technician A says that a voltmeter can be used to monitor the output signal of an optical sensor. Technician B says that optical sensors should be tested with an oscilloscope because of the sensor's speed. Which technician is correct?
Both Technician A and B
Technician A says that a waste spark ignition system fires two spark plugs at the same time. Technician B says that the waste spark ignition system uses ignition coils connected to companion cylinders. Which technician is correct?
Both Technician A and B
Technician A says that all injectors in a sequential fuel injection system often use the same power wire. Technician B says that each injector in a sequential fuel injection system should have a different ground wire. Which technician is correct?
Both Technician A and B
Technician A says that an engine benefitted from system cleaning if the manifold vacuum at idle increases. Technician B says that cleaning the throttle plate and IAC passages will benefit many engines. Which technician is correct?
Both Technician A and B
Technician A says that an idle air control valve controls the airflow past closed throttle plates. Technician B says that the idle air control valve is usually controlled by a stepper motor. Which technician is correct?
Both Technician A and B
Technician A says that fuel pressure regulators are often located on the return side of the fuel rail. Technician B says that the fuel pressure regulator is located at the fuel tank on vehicles using mechanical returnless systems. Which technician is correct?
Both Technician A and B
Technician A says that ignition timing cannot be adjusted on waste spark ignition systems. Technician B says that most waste spark systems use a crankshaft position sensor. Which technician is correct?
Both Technician A and B
Technician A says that in bypass mode, the ignition system is timed by the ignition module. Technician B says that in bypass mode, the ignition system does not use the PCM to time spark plug firing. Which technician is correct?
Both Technician A and B
Technician A says that it requires more voltage to fire the compression cylinder than the companion cylinder. Technician B says that waste spark systems using compression sensing electronics do not require a camshaft sensor for engine position. Which technician is correct?
Both Technician A and B
Technician A says that most fuel injection systems use the PCM to control the pulsing of the fuel injectors. Technician B says that most fuel injection systems use the PCM to control the operation of the fuel pump relay. Which technician is correct?
Both Technician A and B
Technician A says that platinum tipped spark plugs should never be re-gapped after using in a running engine. Technician B says that spark plugs should not be removed from a hot cylinder head. Which technician is correct?
Both Technician A and B
Technician A says that the firing line shows the voltage that is required to fire the spark plug. Technician B says that the spark line shows the duration of the spark inside the cylinder. Which technician is correct?
Both Technician A and B
Technician A says that the fuel pump relay is usually controlled by the PCM. Technician B says that a TBI injector squirts fuel above the throttle plate. Which technician is correct?
Both Technician A and B
Technician A says that the fuel system should be diagnosed first in a no-start condition. Technician B says that the ignition system trigger device is used to synchronize fuel injection. Which technician is correct?
Both Technician A and B
Technician A says that vehicles equipped with an ASD relay only have power at the ignition coil when the engine is cranking or running. Technician B says that a defective ASD relay could cause a no-start condition. Which technician is correct?
Both Technician A and B
Technician A says that vehicles with electronic returnless fuel systems use pulse width modulation to power the fuel pump and maintain fuel pressure. Technician B says that the electronic returnless fuel system use a power transistor to control the fuel pump. Which technician is correct?
Both Technician A and B
The fuel pressure drops rapidly when the engine is turned off. Technician A says that one or more injectors could be leaking. Technician B says that a defective check valve in the fuel pump could be the cause. Which technician is correct?
Both Technician A and B
Two technicians are discussing a no-start (no-spark) condition. Technician A says that an open pickup coil could be the cause. Technician B says that a defective ignition control module (ICM) could be the cause. Which technician is correct?
Both Technician A and B
Two technicians are discussing distributor ignition. Technician A says that the pickup coil or optical sensor in the distributor is used to pulse the ignition module (igniter). Technician B says that some distributor ignition systems have the ignition coil inside the distributor cap. Which technician is correct?
Both Technician A and B
Technician A looks for engine speed (RPM) when cranking an engine that will not start. Technician B says that a problem in the primary circuit could make the tachometer not work. Which technician is correct?
Both Technicians A and B
Technician A says that in bypass mode, the ignition system is timed by the ignition module. Technician B says that in bypass mode, the ignition system does not use the PCM to time spark plug firing. Which technician is correct?
Both Technicians A and B
Which term describes the PCM shutting off fuel injection when the accelerator is pressed all the way down?
Clear flood mode
Which term describes the PCM using oxygen sensor feedback to control fuel delivery?
Closed loop mode
All these terms have been used to describe communication between the ignition module and PCM EXCEPT .
DIS
Which of the following could cause oil fouled spark plugs?
Defective valve stem seals
An ion-sensing ignition system allows the ignition system itself to be able to )Detect misfire Detect spark knock Detect rich or lean air-fuel mixture ***All of these
Detect misfire Detect spark knock Detect rich or lean air-fuel mixture ***All of these
Coil polarity is determined by the
Direction of rotation of the coil windings
HEI and EIS are examples of
Distributor ignition systems
In a typical port fuel injection system, which injectors are most subject to becoming restricted?
Either The injectors at the end of the rail on a returnless system or The injectors at the bends in the rail
Which term describes the principle used to create high voltage from low voltage?
Electromagnetic induction
What component pulses the fuel injector on most vehicles?
Electronic control unit (computer)
Which type of port fuel-injection system uses a fuel temperature and/or fuel-pressure sensor?
Electronic returnless systems
All of the following statements are correct EXCEPT . )Engine speed and position sensors only affect the ignition system. )Defective crankshaft sensors may cause the fuel system to not operate correctly. )Crankshaft sensors may be either magnetic pickup sensors or Hall-effect sensors. )An ignition module should be replaced if it is not switching the ground circuit to the coil or supplying the coil with battery voltage.
Engine speed and position sensors only affect the ignition system.
Which condition below could be caused by a distributer that has been installed incorrectly?
Engine surging Light bucking Intermittent misfire ⦁ All of these are correct
What term describes the order that the spark reaches the cylinders?
Firing order
Which of these is true regarding port fuel injection systems?
Fuel distribution to all cylinders is equal. Fuel is injected almost directly into the combustion camber. The intake manifold may be shaped and sized to best fit the engine performance requirements. ⦁ All of these are correct.
All of the following statements are correct EXCEPT )Fuel injectors on a gang fire system are wired in series. )The resistance of a group of injectors that fire at the same time can be tested together. )Lower than specified injector resistance means the injector is shorted. )None of these.
Fuel injectors on a gang fire system are wired in series.
Which type of port fuel injection groups the injectors into two groups, with each group firing once per crankshaft revolution?
Gang double fired
Which switching device uses a shutter blade and sensor to detect a magnetic field?
Hall-effect switch
The ignition system pickup coil or trigger is usually connected to which device?
Ignition module
The following statements are all correct EXCEPT .
Ignition systems may be disabled by removing the secondary wire from the ignition coil.
Which of the following could cause poor engine operation or no start?
Incorrect firing order Excessive wear in distributor cap Poor ignition wire condition ⦁ All of these are correct
All of the following statements are correct EXCEPT .
Incorrect routing of secondary ignition wires may cause electromagnetic interference with computer circuits. Oil and dirt may cause high resistance in electrical connections. Electrically conductive rubber hose can be used when testing some ignition system secondary circuits. ***All of the statements are correct.
Because of , an ignition coil cannot be fully charged (reach magnetic saturation) until after a delay of about 10 ms
Inductive reactance
Which term describes the electrical current flow in the opposite direction when an injector coil is energized?
Inductive reactance
The following statements are all correct EXCEPT .
Knock sensors require voltage input from the PCM to function properly
On a vehicle with a mass airflow injection system, which of the following is likely to occur with a vacuum leak at idle?
Lean fuel mixture
Which of these describes a condition that results in more fuel being delivered?
Long pulse width
Which of the following describes reasons for poor engine performance in the cold?
Low fuel pressure Insufficient fuel volume Contaminated fuel ⦁ All of the are correct
Which sensor is used to calculate the amount of fuel required using the speed density method?
MAP sensor TP sensor ECT and IAT sensors ⦁ All of these are used
The vacuum hose from the fuel-pressure regulator was removed from the regulator and gasoline dripped out of the hose. Technician A says that this is normal and that everything is okay. Technician B says that one or more of the injectors may be defective, causing the fuel to get into the hose. Which technician is correct?
Neither Technician A nor B
What tool is best to check whether the PCM is pulsing an injector?
Noid light
A reluctor is a
Notched ring or pointed wheel
Which switching device uses LEDs?
Optical sensor
Throttle-body fuel-injection systems use what type of injector driver?
Peak and hold
The ___ sends a pulse signal to an electronic ignition module.
Pickup coil
Which switching device creates its own electrical voltage pulse?
Pickup coil
Which switching device use below is also called a "magnetic pulse generator"?
Pickup coil
Which switching device used below is also called a "magnetic pulse generator"?
Pickup coil
The ignition module has direct control over the firing of the coil(s) of an EI system. Which components(s) triggers (controls) the module?
Pickup coil Computer Crankshaft sensor ⦁ All of these
Dampeners are used on some fuel rails to
Reduce noise
Coil-on-plug ignition systems have which of the following advantages over waste spark systems?
Reduces electromagnetic interference
Why are some fuel rails rectangular in shape?
Reduces noise
The following statements are all correct EXCEPT )Relearning the PCM should never be attempted. )On engines operating very poorly, the PCM should be relearned after fuel system cleaning. )Fuel systems that have never been cleaned may have developed wax deposits as well as carbon. )The fuel rail and pressure regulator should be cleaned as well as fuel injectors.
Relearning the PCM should never be attempted
What should be done if the fuel pressure regulator will NOT hold vacuum?
Replacement
The following statements are all correct EXCEPT
Resistance of the primary ignition coil windings should be infinite.
Which term is used to describe pulses of air flowing from the engine out the air intake due to the time interval between intake events with a four-cylinder engine?
Reverse airflow
Which of the following would cause carbon fouled spark plugs?
Rich fuel mixture
Which of these are symptoms of carbon build-up on throttle plates?
Rough idle Stalling Surging idle ⦁ All of these are correct
Port fuel-injection systems generally use what type of injector driver?
Saturated switch
Which type of port fuel injection allows mixture adjustments between the firing of each cylinder?
Sequential
Which type of port fuel injection fires each injector separately, following the engine firing order?
Sequential fired
What could be the problem if a noid light remains on (does not flash) with the engine cranking?
Short to ground in the injector ground circuit, or defective PCM
The pulse generator
Signals the electronic control unit (module)
Which type of port fuel injection fires all the injectors at the same time, once per crankshaft revolution?
Simultaneous double fired
One type of injection system that does not hold pressure when turned off is called a non-checking system. This is found on
Some General Motors TBI systems
The primary (low-voltage) ignition system must be working correctly before any spark occurs from a coil. Which component is NOT in the primary ignition circuit?
Spark plug wiring
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 the operation of the engine?
Stalls Rough idle Hesitation on acceleration ***Any of these
What type device is used in a typical idle air control?
Stepper motor
Which term is used to describe a system where the injector pulses once per each distributor reference pulse?
Synchronized
Which sensor has the greatest influence on injector pulse width besides the MAF sensor?
TP
Technician A always uses a special service tool to pulse fuel injectors. Technician B says that the injector for each cylinder should only be flow tested four times without starting the engine. Which technician is correct?
Tech A
Technician A says that all the fuel injectors on an engine should have the same electrical resistance. Technician B says that the difference between any two injectors should be less than 2 ohms. Which technician is correct?
Technician A
Technician A says that vacuum-operated fuel pressure regulators allow an equal pressure drop across the fuel injectors all the time. Technician B says that intake manifold pressure is high at idle. Which technician is correct?
Technician A
Technician A says the ignition system should be put in base timing mode before setting ignition timing on distributor ignition systems. Technician B says ignition timing that is too retarded can cause detonation. Which technician is correct?
Technician A
Technician A says to check for spark from the ignition coil first when diagnosing a no-start condition. Technician B says to check the engine speed sensor first to diagnose a no-spark condition. Which technician is correct?
Technician A
Technician A says to pressure clean the fuel system at between 75-90 PSI before starting the engine. Technician B says to pressure clean the fuel system using a 2:1 mixture of solvent to gasoline. Which technician is correct?
Technician A
Technician A says that a voltmeter can be used to monitor the output signal of an optical sensor. Technician B says that optical sensors should be tested with an oscilloscope because of the sensor's speed. Which technician is correct?
Technician B
Technician A says that all port fuel injected systems use the speed density method. Technician B says that throttle body injection systems use the speed density method. Which technician is correct?
Technician B
Technician A says that an engine will not start and run if the ignition coil is tracked. Technician B says that the engine will not start if the crankshaft position sensor fails. Which technician is correct?
Technician B
Technician A says that if fuel pump pressure is correct, fuel pump volume will be correct as well. Technician B says that a fuel pump may produce specified pressure but below specified volume. Which technician is correct?
Technician B
Technician A says that primary windings should have higher resistance. Technician B says that secondary windings should have higher resistance. Which technician is correct?
Technician B
Technician A says that the port fuel injection injectors operate using five volts from the computer. Technician B says that sequential fuel injectors all use a different wire color on the injectors. Which technician is correct?
Technician B
Technician A says that the primary and secondary ignition systems are never connected. Technician B says that the primary and secondary windings are connected in some ignition coils. Which technician is correct?
Technician B
Technician A says that the primary coil has more windings. Technician B says that the secondary coil has more windings. Which technician is correct?
Technician B
Technician A says that the resistance of a pickup coil should never be tested. Technician B checks for AC voltage from the pickup coil when cranking the engine. Which technician is correct?
Technician B
Technician A says to use a normal spark plug when checking for spark. Technician B says that a spark tester should be used to check for spark. Which technician is correct?
Technician B
How many ignition coils should you expect to find on a V6 engine using a waste spark system?
Three
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
What is the name of the electronic component inside the ignition module that opens and closes the primary ignition circuit?
Transistor
The ignition system is usually split into how many different sections?
Two
When looking at a solenoid with an oscilloscope, what event often follow applying or removing power from the coil windings?
Voltage spike
How much voltage is generally available to fuel injectors?
battery voltage
Which statement below is correct?
⦁ *****The primary coil windings are designed for higher current (2-6 Amperes). The secondary coil windings are designed for higher current (2-6 Amperes). The primary coil windings are made of thinner wire than the secondary windings. The primary coil windings have more turns of wire than the secondary windings.
The following statements are all correct EXCEPT
⦁ A lean fuel mixture could cause low firing voltage. Firing lines in the secondary ignition circuit should be between 5-15 kV. Secondary ignition spark lines should be one quarter the voltage of the firing lines. Dwell is the amount of time the ignition module lets currents flow through the primary circuit
Which statement bellow is correct?
⦁ A pickup coil can be diagnosed using a digital storage oscilloscope. A pickup coil should be diagnosed with a meter set to DC volts. Hall-effect sensors should show a constant signal voltage when the engine is cranked. A voltmeter is a better tool than a digital storage oscilloscope to diagnose an engine position sensor.
Which statement below is correct?
⦁ A spark tester requires more voltage than a spark plug to fire A normal spark plug requires more voltage than a spark tester to fire An intermittent spark at the spark plug should never be considered a no-spark condition A defective ignition wire will never cause a no-spark condition
Which statement below is correct?
⦁ Coil on plug systems use one ignition coil per cylinder All coil plug systems require ignition wires Ignition control circuits cannot sense the voltage required to fire a spark plug It is not possible to control the ignition timing for each cylinder separately
Which statement is correct?
⦁ Dirt is most likely to be found near the bottom of the fuel tank. Dirt is most likely to float on top of the fuel. Throttle body injectors inject fuel below the throttle plate. Port fuel injectors inject fuel above the throttle plate.
Which statement is correct?
⦁ Most ignition systems work by switching the circuit grounding the ignition coil's primary windings. Most ignition systems work by switching the circuit to power the ignition coil's primary windings. Most ignition systems work by switching the circuit grounding the ignition coil's secondary windings. Most ignition systems work by switching the circuit to power the ignition coil's secondary windings.
Which statement below is correct?
⦁ Turning off the low voltage primary coil induces a high voltage in the secondary windings. Turning on the low voltage primary coil induces a high voltage in the secondary windings. No voltage is induced in the primary circuit. No voltage is induced in the secondary circuit.
