AUT 134 Midterm

Which of the following is not a common cause of preignition?

Faulty ignition coil

Crude oil is separated into its basic chemical compounds by _________. In this process the crude oil is heated to about 1,200 F and vaporized. Different chemical compounds condense at different temperatures as the vapors pass through a cooling tower.

Fractal distillation

The engine coolant temperature sensor is used to control all of the following except

Fuel pressure

Which of the following components is apart of the primary and secondary ignition circuits?

Ignition Coil

When an engine is running rich, the oxygen content in the exhaust is

Low

Which of the following is not a type of electronic fuel system?

Mass Airflow

Phasers are used to

to advance or retard cam timing

What chemical is added seasonally to gasoline as an anti icing agent to prevent fuel line freeze up in cold weather?

Alcohol

Which of the following are characteristics of burning LP gas?

All of the above

Which of the following is an advantage of an EI system?

All of the above

Which of the following statements is true?

B. (How is a misfire not gonna set a DTC?)

The fuel filter on modern cars is typically mounted......

Under the car

On an OBD II vehicle the DLC is located

Under the dashboard within arms reach of the driver

Which of the following statements about P-Series fuel is not true?

Unlike Ethanol and methanol it cannot be mixed with gasoline

Which of the following statements is not true?

(clue to help find answer ) oxygen sensor has 0 to 1 volt or 12 volts on one side and 0 volts on the other

Most engines have a spark duration approximately

1.5ms

The typical amount of secondary coil voltage required to jump the spark plug air gap is

10,000V

In the past the limited sulphur content for diesel fuel was 500ppm. The current standing for sulphur content in diesel fuel is

15ppm

A vehicle is being diagnosed with a low fuel pressure problem. A fuel pump current test reveals higher than normal current flow. Technician A says that the vehicle may have a clogged fuel filter. Technician B says the fuel pump ground wire maybe loose or corroded. Who is correct?

A only

Fuel lines are being discussed. Technician A says when installing new flexible tubing always use new clamps. Technician B says oridinary fuel rails can be used to replace a kinked steel fuel line. who is correct?

A only

Technician A removes the spark plug wires by grasping the spark plug loop and gently twisting it off. Technician B uses 13/16 in. thin wall to remove spark plugs. Who is correct?

A only

Technician A says that reformulated gasoline produces a leaner air/fuel mixture. Technician B says that ........ produces more carbon dioxide. Who is correct?

A only

Technician A says white or grayish powdery deposits on secondary cables at the point where they cross near metal parts will indicate that the cables insulation is faulty. Technician B says that if the spark plug wire for the number 2 cylinder is damaged and the other wires look good replace only the damaged wire. Who is correct?

A only

Technician A uses the snapshot function on his scan tool to record serial data while doing a test drive for the information can be transferred onto a PC. Technician B uses snapshot feature on his scan tool to record the sensor data that leads up to the vehicle setting a DTC

A only

Technician B says only 10% ethanol to gasoline will result in a decrease of 2.5 - 3 octane points. Technician B says ethanol is highly corrosive and highly toxic. Who is correct?

A only

Coil on plug ignition systems are being discussed. Technician A says COP coils....... . Technician B says COP signal allows the ignition timing for each cylinder to be changed from maximum to cold based on the systems knock sensors.

B only

Crankshaft sensors are being discussed. Technician A says the signal from the hall effect sensor cannot be used to synchronize fuel injectors for timing the engine. Technician B says..........

B only

Diagnostic trouble codes are being discussed. Technician A says a P0442 is a manufacturer code and means different things depending on the manufacturer. Technician B says that a P0304 code is a universal code that means the same thing no matter

B only

Gasoline volatility is being discussed. Technician a says gasoline blended for summer use is more volatile than winter gasoline. Technician B says that at high altitudes gasoline needs to have a higher volatility. Who is correct?

B only

When draining a fuel tank. Technician A says to put the fuel into plastic anti freeze containers then cap them tightly to prevent vent leaks. Technician B drains the fuel into approved gasoline storage containers. Who is Correct?

B only

While discussing ...... service. Technician A says the crankshaft sensor maybe rotated to adjust the basic ignition timing. Technician B says the crankshaft sensor maybe moved to adjust the clearance between the pick up coil and the reluctor on some ignition systems. Who is correct?

B only

While testing a coil from an EI ignition system. Technician A says an infinite reading means that the winding has zero resistance and is shorted. Technician B says the secondary winding of the waste spark double ended coil should be checked by connecting the meter on the secondary terminals. Who is correct?

B only

The number one spark plug fires several degrees.....

Before top dead center

Which of the following is not a location for a ignition module?

Behind the ignition switch

A vehicle was towed to the shop with a crank and no start condition. A check under the hood reveals that the spark plugs are not firing and the injectors are not Receiving pulse from the PCM. Technicians noticed that the MIL light is not on when the key is turned to the on position.

Check cam and crank sensor

What class of fire Extinguisher should be used for gasoline fires?

Class B

What sensor is used to detect engine misfire?

Crankshaft Position sesnor

A clogged fuel filter will cause

D

All of the following statements concerning E85 fuel are all true except

D

All the following are factors that cause knock except...

D

Which of the following statements about carbon tracking is not correct?

D

A MAP sensor with a varying frequency upload can be tested with a

DMM with a frequency function

A no start, no fuel pressure condition is being diagnosed. When a testlight is connected to a positive terminal there is no voltage when the engine is cranked by the starter. What could cause this problem?

Defective fuel pump regulator

Which of the following jobs is not a function of the ignition system?

Engaging starter motor

The first decision the computer makes to determine the best operating strategy is to determine

Engine operation (driving, cruising, ETC.)

Technician A says large low speed industrial diesel requires high quality and high volatility fuel because they cannot tolerate excessive carbon deposits. Technician B says small high speed diesel engines found in passenger cars are unaffected by carbon deposits resulted from low quality fuel. Who is correct?

Neither

Technician A says piezoresistive material is a type of crystal that rapidly shrinks when exposed to electrical current. Technician B says piezoresistive material shrinks slowly when current to it is stopped. Who is correct?

Neither

The engine vacuum is being discussed. Technician A says when the engine is operating under light loads, the engine vacuum is low. Technician B says that when the engine vacuum is high the engine is operating under heavy loads. Who is correct?

Neither

The air gap between the crankshaft position sensor and the trigger wheel is measured with a

Nonmagnetic feeler gauge

Which of the following is not a type of engine position sensor?

Piezoresistive

The first step into removing the fuel tank is to

Remove negative battery cable

One of the advantages to a coil on plug type ignition system is that it eliminates the need for.....

Spark Plug Wires

Which of the following is a component of the secondary circuit?

Spark Plugs

Which of the following tools is not used for testing engine sensors?

Test light

Excessive alcohol in the fuel will cause

all answers

Which of the following tools cannot be used to test an oxygen sensor?

analog

Ignition timing is being discussed. Technician A says when an engines idle speed moves away from the desired speed, the PCM will adjust the timing to stabalize the engine speed. Technician B says that when a knock is detected the PCM will retard the timing in fixed steps until the kncok disapears. Who is correct?

both

Technician A says a magnetic pulse generator generates a small AC voltage each time one of the machined slots in the trigger wheel passes by. Technician B says some ignition systems with dual hall-effect sensors will produce......

both

When 20 inches of vacuum is applied to the fuel pressure regulator, the fuel pressure should

decrease

A high fuel pressure reading is usually caused by a faulty

fuel pressure regulator

All the following are aromatic hydrocarbons accept

kerosine

If the spark line is totally flat, than it is no longer between volts

plug is not firing

Which of the following will not cause the fuel pressure to drop off quickly?

restriction in the fuel filter

The possible cause of a no spark condition on a coil over plug EI system is being discussed. Technician A says no voltage from the crankshaft position sensor will prevent the engine from starting. technician B says a shorted ignition coil can be the cause. Who is correct?

A only

Trouble codes are being discussed. Technician A says the first time the system detects a fault a pending code is set. Technician B says the pending code will turn on the MIL light. Who is correct?

A only

Methanol can be made from__________

All of the above

Using gasoline with high levels of sulphur could cause

All of the above

A fuel system that runs at 35 to 50 psi should draw around ___________ amps of current

B

Technician A says ..... are dedicated impulse ..... are designed to use only one type of fuel. Technician B says that ..... are alcohol based fuel or unleaded gasoline which gives the driver Flexibility for refueling their vehicle. Who is correct?

B

Hydrogen fueled vehicles are being discussed. Technician A says hydrogen can be made from from natural gas. Technician B says hydrogen can be made from water. Who is correct?

Both

Catalytic converter Monitors are being discussed. Technician A says that if a computer is reading the downstream signal frequency shouldn mirror the upstream sensor. Technician B says that the downstream sensor should provide a low voltage frequency signal. Who is correct?

B only

A technician is setting up a lab scope to measure a sensor. Technician A says that the vertical voltage scale on the voltage scale must be adjusted in relation to the expected voltage signal. Technician B says that the trigger slope must be set to the positive if the trace begins with a rising voltage.

Both

Crankshaft sensors are ________ type sensors

Both

EGR Monitors are being discussed. Technician a says some EGR systems Monitors EGR flow By measuring the difference in pressure As the EGR gas flows through An orifice restriction. Technician B Says some EGR monitors Measure the temperature of the EGR outlet To determine whether there is gas flowing through The EGR valve. Who is correct?

Both

Fuel pressure readings are being discussed. Technician A says high fuel pressure can be caused by a faulty fuel pressure regulator. Technician B says low fuel pressure can be caused by a defective fuel pressure regulator. Who is correct?

Both

Octane ratings are being discussed. Technician A says most modern engines are designed to use regular gas. Technician B says to only use high octane gasoline only when the engine was designed to use it. Who is correct?

Both

Operating modes are being dicussed. Technician A says that when an engine is in closed loop mode the PCM Monitors the sensor outputs to adjust the timing and air fuel ratios and ignition controls. Technician B says the system will switch into open loop when the valve is fully open or if the oxygen sensors are cooled down during......

Both

Technician A connects a fuel pressure gauge to a Schrader air valve on the fuel rail. Technician B connects the gauge to the fuel line by inserting a T adapter behind the fuel filter and the fuel rail. Who is correct?

Both

Technician A says ...... uses high octane gasoline therefore most power is generating during combustion. Technician B says using a higher octane gasoline that requires more power to start, the engine has a knock sensor that alerts the system.......

Both

Technician A says a fouled spark plug can cause a misfire. Technician B says a bad coil can cause a misfire. Who is correct?

Both

Technician A says diesel engines use less fuel per mile than gasoline engines of the same size. Technician B says diesel engines produce more torque than gasoline engines of the same size. Who is correct?

Both

Technician A says lean ratios of 15:1 to 16:1 provide the best fuel economy. Technician B says rich mixtures below 14.7:1 will provide the most power to the engine but greater fuel consumption. Who is correct?

Both

Technician A says that on some vehicles fuel pressure is monitered by the fuel (nail angle?) pressure sensor..... is controlled by the PCM with pulse width modulation. Technician B the symptoms ....

Both

Technician A says the best method for Permanently solving a leaking metal fuel tank is to replace the tank. Technician B says a leaking plastic fuel tank can sometimes.....

Both

Technician A says white smoke in the exhaust of a diesel engine could be the result of fuel not burning inside a hot engine. Technician B says blue smoke from the exhaust of a diesel engine can be caused by scoring of the cylinder walls. Who is correct?

Both

While discussing a one ignition coil for every two cylinders. Technician A says two plugs fire at the same time with one wasting the spark on the exhaust stroke. Technician B says one plug fires in one direction while the other fires in reversed polarity. Who is correct?

Both

While discussing an ignition problem that is displayed on a scope with the primary ignition pattern. Technician A says a worn distributor drive gear can cause erratic traces on the signal. Technician B says if theres erratic voltage spikes at the transistor on signal, the ignition module may be faulty. Who is correct?

Both

While discussing common rail fuel injection systems Technician A says the individual injectors are activated by the high pressure present in the fuel rail. Technician B says some late model CR systems have an Intensifier in the injector that allows for an increase in fuel pressure. Who is correct?

Both

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

What type of fouling occurs immediately following after an overdue tune up?

C (not glazing, not cold fouling, or donuts.)

Older engines with non-carbon valve seats may need a _________ substitute to be added to the fuel to prevent premature valve seat wear.

Lead

Which of the following will not cause an oxygen sensor to appear bad?

Leaking muffler to tailpipe gasket

Spark plug wires are being discussed. Technician A says silicone insulated wires are used for normal temperature applications. Technician B says silicone wires are used for high temperature applications. Who is correct?

Neither

A vehicle with a DTC of coolant temp out of range is being diagnosed. serial data stream shows that the coolant temp to be 198 degrees Fahrenheit. when the technician tests the resistance between ECT terminals he finds an infinite resistance. The specification calls for 20 to 40 ohms at 200 Degrees Fahrenheit. After the ECT is replaced and the code is erased the system runs normally and the code and the MIL do not reoccur.

The PCM substituted a nominal ECT value that allow the engine to run in limp home mode which substitute value was displayed on the scan tool.