Mid Course Exam
To complete a four stroke cycle in one cylinder, the crankshaft must rotate___ degrees
720
Which of the following is NOT a spark plug thread diameter?
9.16 in
Which of the following problem is NOT cause by a misfire?
High idle speed
Which one of the following is NOT a stroke of the four-stroke cycle?
Ignition
Spark plug firing voltage should be normally be ____
7 to 13 kV
the typical amount of secondary coil voltage require to jump the spark plug gap is___volts
...
How many degrees crankshaft rotation does it take to complete one complete engine cycle in a 4-stroke engine?
720
The hex size [socket size] used for tightening and loosing the spark plugs is either 5/8 in or
13/16 in.
Which of the following comp net is part of the primary ignition circuit
ignition switch
Possible causes for a no-start condition on a coil-over plug EI engine are being discussed. Technician A says a faulty crankshaft sensor may be prevent the engine from starting. Technician B says a shorted ignition coil may be the cause. Who is correct?
A only
Technician A performs a cylinder performance test [power balance test] to determine which cylinder is misfiring. Technician B uses vacuum gauge to pinpoint the misfiring cylinder. Who is correct?
A only
Technician A removes plug wires by grasping the spark plug boot and gently twisting it off. Technician B uses a 13/16 in. deep thin wall socket to remove the spark plugs. Who is correct?
A only
Technician A says the engine displacement can be found on the engine ID tag. Technician B says the date the engine was assembled can be found in the casting numbers in the cylinder block. Who is correct?
A only
the firing lines on an oscilloscope are all abnormally low. Technician A says the problem could be faulty coil. Technician B says the problems could be lean air/fuel mixture who is correct?
A only
In what type of engine is the intake valve held open longer than normal during the compression stroke?
Atkinson Cycle
what type of ICE engine listen below is commonly found in a hybrid vehicle
Atkison
Crankshaft sensors are being discussed. Technician A says the signal from a Hall-effect CKP cannot be used to synchronize fuel injector timing with the engine. Technician B says some early distributor systems relied on photoelectric sensors to monitor crankshaft position. Who is correct?
B only
Technician A says a plug with a V-notch ground electrode will have two electric arcs jumping across the spark plug gap each time the spark plug fires. Technician B says a spark plug gap that is too wide requires higher voltage to jump the gap, which can cause a misfire. Who is correct?
B only
Technician A says large amounts of EMI can collapse the fields in a coil and cause a plug to fire. Technician B says poor spark plug cable insulation may cause EMI. Who is Correct?
B only
While discussing EI services. Technician A says the crankshaft sensor may be adjusted the basic ignition timing/ Technician B says the crankshaft senor may be moved to adjust the clearance between the pickup coil and reluctor on some EI systems. Who is correct?
B only
computer controlled ignition timing is being discussed. Technician A says when excessive wheel slippage occurs the pcm will advance the timing to increase the torque output from the engine Technician B says provide smooth shifting of an automatic transmission, the PCM will temporarily regard the ignition timing reduce the engine torque when the transmission is beginning to change gears
B only
Technician A says engine displacement is commonly measures in cubic millimeters. Technician B says it is commonly measured in cubic inches. Who is correct?
B only.
On a oscilloscope which section ends with the primary coil current off signal?
Dwell
Resistor type spark plugs are being discussed. Technician A says the resistor increased the plug firing voltage. Technician B says the resistor helps reduce radio frequency interference (RFI) , which can interfere with or dame, radios, computers, and other electric accessories, such as GPS systems. Who is correct?
Both A & B
Technician A says a magnetic pulse generator type sensor generates a small AC voltage each time one of the machines slots in the trigger wheel passes by. Technician B says some ignition system use dual Hall-effect sensors that produce a 3% and 18x/revolution pulse. Who is correct?
Both A & B
While discussing an ignition problem displayed on a scope primary ignition pattern. Technician A says a worn distributor drive gear can cause an erratic transistor ON signal. Technician B says if there are erratic voltage spikes at the transistor ON signal, the ignition module may be faulty. Who is correct?
Both A & B
While discussing electronic ignition systems. Technician A says an NPN transistor in the PCM or ignition module controls primary current flow through the coil. Technician B says coil saturation is controlled by the length of time the primary ignition current is turned on. Who is Correct?
Both A & B
Technician A says a fouled spark plug can cause a misfire, Technician B say s a bad coil can cause a misfire. Who is correct?
Both A and B
Technician A says a loose ignition module mount can cause intermittent misfire or no start conditions, Technician b says when installing a new ignition module, a small amount of heat conductive grease should be applied to the mounting surfaces. Who is correct?
Both A and B
Two technician are discussing waste spark ignition systems. Technician A says that half of the spark plugs in the system fire in revered polarity {from the ground electrode to the center electrode} technician B says that two spark plugs are connected in series with the coil . Who is correct?
Both A and B
ignition coil testing is being discussed. Technician A uses an ohmmeter to measure primary and secondary resistance. Technician B uses an oscilloscope and a test spark plus to measure maximum coil output voltage. Who is correct?
Both A and B
Crankshaft position senors (CKP) are_____ type sensors
Both hall-effect and magnetic pulse generators
Front engine, longitudinal layout is being discussed. Technician A says this layout is used in rear-wheel drive vehicles. Technician B says this layout is used in some front wheel drive vehicles. Who is correct?
Both.
which of the following statement about carbon tracking is NOT correct?
Carbon tracking usually occurs in the primary ignition circuit
Which of the following engine problems may be indicated by good results from a compression test and a cylinder leakage test but poor results from a cylinder power balance test?
Collapsed lifter
EI systems are being discussed. Technician A says a waste spark system has one coil per cylinder. Technician B says coil on plug system uses a double ended coil. Who is correct?
Neither A nor B
Engine oil pressure testing is being discussed. Technician A says that oil pressure should be tested with the engine cold. Technician B says oil with viscosity that is too high may cause lower than specified pressure. Who is correct?
Neither A nor B.
Resistor plugs are being discussed. Technician A says that if the original equipment resistor plugs are replaced with non resistor plugs, the engine will produce more power at high RPM, Technician B says that if the original equipment resistor plugs are replaced with the non resistor plus, the engine will run smoother at low RPM, Who is correct?
Neither A or B
What type of fouling occurs immediately following an overdue tune up
Splash fouling
The stroke of an engine is__ that of a crankshaft throw
Twice
A four stroke cycle engine requires at least___ valves at the top of each cylinder
Two
The heat range of a spark plug is indicated by
a code within the plug number imprinted on the side of the spark plug
To minimize EMI interference, sensor wires should be routed away from ___
all answers are correct (spark plug wires) (distributor caps) (ignition coils)
What component of the engine determines the stroke?
crankshaft
spark plug cables from consecutively firing cylinders should____
cross rather than run parallel to one another
Leaner air/fuel mixtures___
increase the electrical resistance inside the cylinder and increase the required firing voltge.
the magnetic field surrounding the pick up coil in magnetic pulse generator moves when the ___
reluctor tooth begins to move away from the pick up coil.
Modern ingition cables contain carbon fiber cores that act as an___ in the secondary circuit to cut down on radio and television interferince and reduce spark plug wear
resistor
One of the advantages of a coil-on plug type ignition system is that it climates the need for
spark plug wires
Reach heat range and air gap are all characteristics that affect the performance of which ignition system component
spark plugs