AST 3 Final Diagnosis and Tune Up

Air filters can remove particles and dirt as small as ________.

10 to 25 microns

How quickly can the rocker arms be switched from the low-speed camshaft profile to the high-speed camshaft profile on a Honda equipped with a VTEC system?

100 milliseconds

How much compressed natural gas (CNG) does it require to achieve the energy of one gallon of gasoline?

122 cubic feet

Cranking vacuum should be ________.

2.5 inches Hg or higher

At about what temperature does oxygen combine with the nitrogen in the air to form NOx?

2500 deg F

Intake charge velocity has to be at least ________ to prevent fuel droplet separation.

50 feet per second

What is the commanded pulse width of the camshaft phaser that results in the desired position?

50%

A good engine should produce how much compression during a running (dynamic) compression test?

60-90 PSI

One cylinder of an automotive four-stroke cycle engine completes a cycle every ________.

720 degree

E85 means that the fuel is made from ________.

85% ethanol, 15% gasoline

The proper term for Vise-Grip is___________________. A: Locking Pliers B: Slip Joint Pliers C: Side Cuts D: Multi Groove adjustable pliers

A

What type of hammer is plastic coated, has a metal casing inside, and is filled wioth small lead balls? A: Dead Blow Hammer B: Soft Blow Hammer C: Sledge Hammer D: Plastic Hammer

A

What type of screwdriver should be used if there is very limited space above the head of the fastener? A; Offset screwdriver B: Standard screwdriver C: Impact Screwdriver D: Robertson screwdriver

A

A good reading for a cylinder leakage test would be ________.

All cylinders below 20% leakage

A stuck open thermostat can cause ________.

All of the above

Methanol is also called ________.

All of the above

The ignition module has direct control over the firing of the coil(s) of an EI system. Which component(s) triggers (controls) the module?

All of the above

Variable valve timing can be found on which type of engine?

All of the above

What sensors are used by the PCM to determine the best position of the camshafts for maximum power and lowest possible exhaust emissions?

All of the above

Winter blend gasoline ________.

All of the above

A flex-fuel vehicle can be identified by ________.

Any of the above

Ethanol can be produced from what products?

Any of the above

A fastener that uses threads on both ends is called a _________________________. A: Cap screw B: Stud C: Machine screw D: Crest fastener

B

A high strength bolt is identified by_______________________. A: A UNC symbol B: Lines on the head C: Strength letter codes D: The coarse threads

B

Two technicians are discussing torque wrenches. Technician A says that a torque wrench is capable of tightening a fastener with more torque than a conventional breaker bar or ratchet. Technician B says that a torque wrench should be calibrated regularly for the most accurate results. Which technician is correct? A: Technician A only B: Technician B only C: Both Technicians A and B D: Neither Technician A or B

B

When working with hand tools always________________________. A: Push the wrench-don't pull it toward you B: Pull the wrench-don't push it away from you

B

Before an evaporative emission monitor will run, the fuel level must be where?

Between 15 and 85%

The weep hole on a water pump is located where?

Between the seal and the bearing

A P0401 is being discussed. Technician A says that a stuck-closed EGR valve could be the cause. Technician B says that clogged EGR ports could be the cause. Which technician is correct?

Both technicians

Exhaust passages are included in some intake manifolds. Technician A says that the exhaust passages are used for exhaust gas recirculation (EGR) systems. Technician B says that the exhaust heat is used to warm the intake charge on some engines equipped with a throttle-body-type fuel-injection system. Which technician is correct?

Both technicians

Technician A says that a bleeder valve is located on many engines to allow air to escape when refilling the cooling system. Technician B says that a hose should be attached to the bleeder valve to allow any escaping coolant to be directed to a suitable container. Which technician is correct?

Both technicians

Technician A says that a cracked exhaust manifold can affect engine operation. Technician B says that a leaking lower intake manifold gasket could cause a vacuum leak. Which technician is correct?

Both technicians

Technician A says that carbon inside the engine can cause excessive NOx to form. Technician B says that excessive NOx could be caused by a cooling system fault causing the engine to operate too hot. Which technician is correct?

Both technicians

Technician A says that in going to high altitudes, engines produce lower power. Technician B says that most engine control systems can compensate the air-fuel mixture for changes in altitude. Which technician is correct?

Both technicians

Technician A says that some intake manifolds are plastic. Technician B says that some intake manifolds are constructed in two parts or sections: upper and lower. Which technician is correct?

Both technicians

Technician A says that spark knock, ping, and detonation are different names for abnormal combustion. Technician B says that any abnormal combustion raises the temperature and pressure inside the combustion chamber and can cause severe engine damage. Which technician is correct?

Both technicians

Technician A says that the paper test could detect a burned valve. Technician B says that a grayish white stain could be a coolant leak. Which technician is correct?

Both technicians

Technician A says that the research octane number is higher than the motor octane number. Technician B says that the octane rating posted on fuel pumps is an average of the two ratings. Which technician is correct?

Both technicians

The switching valves on the AIR pump have failed several times. Technician A says that a defective exhaust check valve could be the cause. Technician B says that a restricted exhaust system could be the cause. Which technician is correct?

Both technicians

Two technicians are discussing clogged EGR passages. Technician A says clogged EGR passages can cause excessive NOx exhaust emission. Technician B says that clogged EGR passages can cause the engine to ping (spark knock or detonation). Which technician is correct?

Both technicians

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 technicians

Two technicians are discussing oil leaks. Technician A says that an oil leak can be found using a fluorescent dye in the oil with a black light to check for leaks. Technician B says that a white spray powder can be used to locate oil leaks. Which technician is correct?

Both technicians

In this drawing, which item is the camshaft?

C

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 indicates efficiency? (The higher the level of this gas, the more efficient the engine is operating.)

CO2

Which EVAP valve(s) is (are) normally closed?

Canister purge valve

The intake manifold of a port fuel-injected engine ________.

Contains only air

Why are the EGR gasses cooled before entering the engine on some engines?

Cool exhaust gas is more effective at controlling NOx emissions.

For the best working position, the work should be ____________________________. A: At neck or head level B: At knee or ankle level C: Overhead by about 1 foot D: At chest or elbow level

D

The correct location for the pads when hoisting or jacking the vehicle can often be found in the_______________________________. A: Service Manual B: Shop Manual C: Owner's manual D: All of the above

D

The proper term for Channel Locks is_____________________. A: Vise-Grip B: Crescent Wrench C: Locking Pliers D: Multi groove adjustable pliers

D

An engine fails to reach normal operating temperature. Which is the most likely fault?

Defective thermostat

Vapor lock can occur ________.

During both A and B

What can be used to measure the alcohol content in gasoline?

Either A or B

Used coolant should be ________.

Either B or C

A smoothly operating engine depends on ________.

Equal compression between cylinders

Permanent antifreeze is mostly ________.

Ethylene glycol

Which part of the four stroke cycle is illustrated in this drawing?

Exhaust

To reduce oxides of nitrogen (NOx) exhaust emissions, which camshaft is varied?

Exhaust camshaft only

A water pump is a positive displacement-type pump.

False

Producing liquid fuel from coal or natural gas usually uses which process?

Fischer-Tropsch

Horsepower is expressed in units of ________.

Foot-pounds per minute

All of the gasses are measured in percentages EXCEPT ________.

HC

An ignition fault could cause excessive ________ exhaust emissions.

HC

All overhead valve engines ________.

Have the overhead valves in the head

Which method of blending ethanol with gasoline is the most accurate?

In-line

To avoid problems with the variation of gasoline, all government testing uses ________ as a fuel during testing procedures.

Indolene

To increase engine performance, which camshaft is varied?

Intake camshaft only

Avoid topping off the fuel tank because ________.

It can saturate the charcoal canister

Which alcohol is dangerous (toxic)?

Methanol

A clogged EGR passage could cause excessive ________ exhaust emissions.

NOx

Which gas is generally considered to be the lean indicator? (The higher the level of this gas, the leaner the air-fuel mixture.)

O2

How many rotations of the crankshaft are required to complete each stroke of a four-stroke cycle engine?

One-half

Which diagnostic trouble code (DTC) may be set if there is a problem with the bank 1 intake cam position?

P0011

If the incorrect grade of engine oil is used in and engine equipped with a variable displacement engine, what diagnostic trouble code (DTC) could be set?

P0521

The upper portion of a two part intake manifold is often called the ________.

Plenum

Torque is expressed in units of ________.

Pound-feet

Liquefied petroleum gas (LPG) is also called ________.

Propane

Which is the most widely used alternative fuel?

Propane

How is the camshaft actuator controlled?

Pulse width modulated (PWM) signal

What test is being performed in this illustration?

Radiator cap pressure test

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

Technician A says that high HC emission levels are often caused by a fault in the ignition system. Technician B says that high CO2 emissions are usually caused by a richer-than-normal air-fuel mixture. Which technician is correct?

Technician A only

Technician A says that the crankshaft determines the stroke of an engine. Technician B says that the length of the connecting rod determines the stroke of an engine. Which technician is correct?

Technician A only

Technician A says that during a power balance test, the cylinder that causes the biggest RPM drop is the weak cylinder. Technician B says that if one spark plug wire is grounded out and the engine speed does not drop, a weak or dead cylinder is indicated. Which technician is correct?

Technician B only

Technician A says that if a PCV valve rattles, then it is okay and does not need to be replaced. Technician B says that if a PCV valve does not rattle, it should be replaced. Which technician is correct?

Technician B only

Two technicians are discussing testing a catalytic converter. Technician A says that a vacuum gauge can be used and observed to see if the vacuum drops with the engine at idle for 30 seconds. Technician B says that a pressure gauge can be used to check for backpressure. Which technician is correct?

Technician B only

If the engine oil is not changed regularly, what is the most likely fault that can occur to an engine equipped with variable valve timing (VVT)?

The filter screens on the actuator control valve become clogged

As the percentage of antifreeze in the coolant increases, ________.

The freeze point decreases (up to a point)

When refueling a CNG vehicle, why is it recommended that the tank be filled to a high pressure?

The range of the vehicle is increased

Which statement is true about thermostats?

The temperature marked on the thermostat is a temperature at which the thermostat should start to open.

The coolant flow through the radiator is controlled by the ________.

Thermostat

A heated air intake system is usually necessary for proper cold-engine driveability on ________.

Throttle body fuel injection systems

Why do many port fuel injected engines use long intake runners?

To increase low RPM torque

After the following exhaust emissions were measured, how was the engine operating? HC=766 PPM CO2=8.2% CO=4.6% O2=0.1%

Too rich

Using ethanol-enhanced or reformulated gasoline can result in reduced fuel economy.

True

How many camshafts does a SOHC V-8 engine have?

Two

How much air flows through the PCV system when the engine is at idle speed?

Up to 30%

Which of the following is the least likely to cause an engine noise?

Vacuum leak