Final Exam Engine Performance week 1-5

A vehicle with a MIL illuminated is being diagnosed. The Diagnostic Trouble Code (DTC) stored is a P0302 (Cylinder number 2 Misfire detected). Which test should a drivability technician perform first to diagnose this code? Ignition System Test Fuel System Test Vacuum Test Compression Test Both a and b

Vacuum Test

A vehicle with a MIL illuminated is being diagnosed. The Diagnostic Trouble Code (DTC) stored is a P0302 (Cylinder number 2 Misfire detected). Which test should you perform first to diagnose this code? Ignition System Test Fuel System Test Vacuum Test Compression Test Both a and b

Vacuum Test

A customer invoice states the primary concern of "poor performance when accelerating." The first thing the technician should do is? Check for codes and TSBs Check Engine Vacuum Perform a visual inspection Verify the customer complaint

Verify the customer complaint

In the automotive industry, traditionally normal burn time for an ignition system is considered to be: .5-1 mS 1.5-2.0 mS 2.5-3.3 mS 3 mS

1.5-2.0 mS

The minimum voltage level required for the primary ignition system is: 8 volts 10 volts 12 volts 14.5 volts

10 volts

3/4 or 75% state of charge for a battery is: 12 volts 12.5 volts 8 volts 12.4 volts

12.4 volts

When checking the resistance of spark plug wires, the resistance should be 10,000 ohms per foot 5,000 ohms per foot 7,000 ohms per foot 4,000 ohms per foot

4,000 ohms per foot

When checking the resistance of spark plug wires, the resistance should be 4,000 ohms per foot 5,000 ohms per foot 7,000 ohms per foot 10,000 ohms per foot

4,000 ohms per foot

A vehicle with electronic spark timing control has low power and need its base ignition timing adjusted. Technician A says the ignition timing on a distributor type ignition system is usually set with the engine running at idle and the computer control disabled. Technician B says base timing is usually set with the engine running at 2,500 RPM. Who is correct? A Only B Only Both A and B Neither A or B

A Only

Technician A says a multiple cylinder misfire could be caused by a defective coil on a waste spark system. Technician B says a low resistance in the primary circuit can reduce secondary circuit kV output. Who is correct A Only B Only Both A and B Neither A or B

A Only

Technician A says the ignition system secondary circuit is designed to produce thousands of volts. Technician B says the secondary circuit produces dangerously high amperage. Who is correct? A Only B Only Both A and B Neither A or B

A Only

Technician A says the ignition system secondary circuit produces dangerously high volts. Technician B says the secondary circuit produces dangerously high amperage. Who is correct? A Only B Only Both A and B Neither A or B

A Only

Two technicians are discussing a vehicle with P0301 misfire code and a COP ignition system. Technician A says if the spark plug that is wet with fuel it is likely an ignition misfire. Technician B says if you move the coil to # 2 cyl and it still misfires on #1 then it may have a bad coil . Who is correct? A Only B Only Both A and B Neither A or B

A Only

Two technicians are discussing engine misfires. Technician A fuel trim numbers should be between plus or minus 10%says. Technician B says a power balance test should be performed to see if the misfire is related to the ignition system. Who is correct? A Only B Only Both A and B Neither A or B

A Only

Two technicians are discussing engine misfires. Technician A says a crankshaft variation relearn procedure should be performed as an initial step when diagnosing a GM vehicle. Technician B says Ford Mode 6 data will only indicate ignition related misfires. Who is correct? A Only B Only Both A and B Neither A or B

A Only

Technician A says a coil with weak reserve voltage could cause a misfire under acceleration. Technician B says the ignition coil only produces enough secondary voltage to jump the spark plug gap. Who is correct? A Only B Only Both A and B Neither A or B

A Only (as an engine accelerates the required voltage increases)

Two technicians are discussing engine misfires. Technician A says the misfire may be caused by a vacuum leak if it misfires at low rpm but not at high. Technician B says an ignition misfire will show up on your a relative compression test. Who is correct? A Only B Only Both A and B Neither A or B

A Only (as an engine accelerates the required voltage increases)

What is the Definition of A misfire?

A misfire: a cylinder that does not make power on the powerstroke

Coolant has been found in the engine oil of a vehicle. Technician A says a leaking oil cooler may be the cause. Technician B says overfilling the engine oil may be the cause. Who is correct? . A only B only Both A and B Neither A or B

A only

Two technicians are discussing Voltage drop testing. Technician A says that an open circuit reading will display battery voltage. Technician be says that a voltage drop test cannot detect open circuits. Who is correct? A only B only Both A and B Neither A or B

A only

Two technicians are discussing ignition timing corrections for production cars. Technician A says ignition timing will be advanced for high rpm. Technician B says that ignition timing will advance when there is high engine load. Who is correct? A only B only Both A and B Neither A or B

A only (B is incorrect ignition timing will retard for high engine load)

A vehicle with electronic ignition fails to start. Which of the following should be checked? Spark Fuel Pressure Injector Pulse All of the above only spark and injector pulse

All of the above

A disconnected spark plug wire was found on an engine that was misfiring. Technician A says the PCM should be replaced because the open wire could have spiked the PCM. Technician B says that discharging the coil internally can damage the ignition coil. Who is correct? A Only B Only Both A and B Neither A or B

B Only

An open spark plug wire was found on an engine that was misfiring. Technician A says that the PCM should be replaced because the open spark plug wire will damaged the module. Technician B says the ignition coil should be replaced because the open wire will stress the coil and shorten the life of the coil. Who is correct? A Only B Only Both A and B Neither A or B

B Only

Technician A says a misfire on one cylinder could be caused by a defective coil on a vehicle with a waste spark system. Technician B says if there is high resistance in the primary circuit the secondary circuit kV output will be reduced. Who is correct A Only B Only Both A and B Neither A or B

B Only

Two technicians are discussing carbon tracking discovered on number 3 cylinder. Technician A says only the spark plug needs to be replaced. Technician B says the spark plug and the spark plug boot should be replaced.. Who is correct? A Only B Only Both A and B Neither A or B

B Only

Two technicians are discussing engine misfires. Technician A fuel trim numbers should be between plus or minus 15%says. Technician B says TSBs should be checked. Who is correct? A Only B Only Both A and B Neither A or B

B Only

The following compression readings were taken on a DOHC V6 engine with separate timing chains. Bank 1: 145, 146, 140; Bank 2: 165, 170, 168. Technician A says that these readings indicate a blown head gasket. Technician B says that these readings may indicated possible problems with the timing chain on Bank 1. Who is correct? A only B only Both A and B Neither A or B

B only

The following compression readings were taken on a DOHC V6 engine with separate timing chains. Bank 1: 145, 146, 140; Bank 2: 165, 170, 168. Technician A says that these readings indicate a flat cam. Technician B says that these readings may indicated problems with the timing chain on Bank 1. Who is correct? A only B only Both A and B Neither A or B

B only

What is Resistance?

Resistance is the amount of voltage that is withheld in a circuit causing voltage to decrease/lessen.

Two technicians are discussing the ignition coil operation. Technician A says that the coil will fire immediately after the primary circuit closes. Technician B says the coil will fire immediately after the primary circuit opens. Who is correct? A only B only Both A and B Neither A or B

B only

Two technicians are discussing the ignition coil operation. Technician A says that the secondary circuit in the coil will fire immediately after the ignition module transistor is turned on. Technician B says the secondary circuit in the coil will fire immediately after the ignition module transistor is turned off. Who is correct? A only B only Both A and B Neither A or B

B only

The following Cranking Compression readings were taken on an engine: Bank 1: 125, 130, 135 and Bank 2: 72, 68, 128. The most likely cause would be?: Burned exhaust valve Blown head gasket worn exhaust cam lobe worn rings

Blown head gasket

A vehicle with electronic ignition fails to start. Technician A says this could be caused by a defective cam sensor. Technician B says this could be caused by a defective ignition coil. Who is correct? A Only B Only Both A and B Neither A or B

Both A and B

During a cylinder power balance test, there is no RPM drop for number 2 cylinder. Technician A says that #2 cylinder is not contributing to the power of the engine. Technician B says that #2 cylinder may have a defective spark plug. Who is correct? A Only B Only Both A and B Neither A or B

Both A and B

Technician A says a coil with weak reserve voltage could cause high HC emissions. Technician B says the ignition coil must always produce more than enough secondary voltage to jump the spark plug gap. Who is correct? A Only B Only Both A and B Neither A or B

Both A and B

Technician A says a single cylinder misfire could be caused by a defective coil on some vehicles. Technician B says a voltage drop of .5 Volt in the primary circuit can reduce secondary circuit kV output. Who is correct A Only B Only Both A and B Neither A or B

Both A and B

Technician A says that a voltage drop test can detect resistance in a circuit. Technician B says that a voltage drop test can detect an open circuit. Who is correct? A only B only Both A and B Neither A or B

Both A and B

Technician A says that an Ammeter must be connected in series with the circuit to measure current. Technician B says that if an ammeter is hooked up to a circuit incorrectly it can blow the fuse in the meter. Who is correct? A only B only Both A and B Neither A or B

Both A and B

Technician A says that if there is no spark from the secondary circuit you should check the primary circuit. Technician B says that the primary circuit is the control circuit where the triggering begins for the secondary ignition circuit. Who is correct? A only B only Both A and B Neither A or B

Both A and B

Technician A says that the secondary circuit will not operate if the primary circuit is not working. Technician B says that the primary circuit is the control circuit where the triggering begins for the secondary ignition circuit. Who is correct? A only B only Both A and B Neither A or B

Both A and B

Two Technicians are discussing a maintenance tune up. Technician A says anti-seize should be put on the threads of the spark plug. Technician B says that platinum spark plugs should not be gapped. Who is correct? A only B only Both A and B Neither A or b

Both A and B

Two Technicians are discussing engine mechanical diagnosis. Technician A says fuel in the coolant indicates a blown head gasket. Technician B says that if valves are adjusted with too little clearance it may cause rough running and a burned valve. Who is correct? A only B only Both A and B Neither A or B

Both A and B

Two technicians are discussing firing kV. Technician A says that over 30 kV may be an indicator of high resistance in the spark plugs or wires. Technician B says that normal kV should be around 8,000-15,000 volts. Who is correct? A only B only Both A and B Neither A or B

Both A and B

Two technicians are discussing ignition scope patterns. Technician A says a fouled spark plug causes long burn time. Technician B says that there should be at least 3 coil oscillations in an ignition voltage signature. Who is correct? A only B only Both A and B Neither A or B

Both A and B

Two Technicians are discussing a vehicle that has high exhaust backpressure readings before and after the catalytic converter. Technician A says the catalytic converter may be defective. Technician B says that the muffler may be restricted. Who is correct? A only B only Both A and B Neither A or B

Both A and B (Both Techs are correct. The muffler is likely restricted but the cat is the likely culprit that came apart and plugged the muffler.)

A vehicle with electronic ignition fails to start. Technician A says this could be caused by a defective cam sensor. Technician B says this could be caused by a defective crank sensor. Who is correct? A Only B Only Both A and B Neither A or B

Both A and B (as an engine accelerates the required voltage increases)

Two technicians are discussing ignition scope patterns. Technician A says a fouled spark plug may cause long burn time. Technician B says that there should be at least 3 coil oscillations in an ignition voltage signature. Who is correct? A only B only Both A and B Neither A or B

Both A and B (as an engine accelerates the required voltage increases)

An example of the designation for a splice in an electrical diagram would be: C102 S102 102 102-5

S102

Carbon Dioxide

Combustion Efficiency

What is Amperage?

Current or the amount of electrons being pushed through a circuit/conductor/wire.

In a two bulb parallel circuit if you add a third bulb the total resistance of the circuit will: Stay the same Decrease Increase None of the above

Decrease

Ignition system misfires will cause which emission(s)? HC NOx CO All of the above are correct

HC

A cylinder misfire may cause all the following EXCEPT: High oxygen levels in the exhaust High hydrocarbon emissions Damage to the catalytic converter High carbon dioxide readings

High carbon dioxide readings

What is a Voltage Drop use for?

How we measure resistance in a circuit thus identifying electrical components that are ineffective or weak.

How would you perform a voltage drop on the Blower motor?

I would connect the positive lead on my multimeter to the blower motor and ground my other lead.

The voltage level required in the secondary ignition circuit increases under all of the follow conditions EXCEPT: Spark plug air gap increases Air fuel mixture is lean Ignition timing is over advanced Air fuel mixture is under higher pressure

Ignition timing is over advanced

A test light is connected between the negative side of the ignition coil and ground while the engine is cranked. Technician A says a blinking test light could be caused by a defective ignition module. Technician B says a blinking test light could be caused by a defective pickup coil. Who is correct? A Only B Only Both A and B Neither A or B

Neither A or B

Carbon Monoxide

Rich Indicator

Oxygen

Lean indicator

Two Technicians are discussing engine mechanical diagnosis. Technician A says oil in the coolant indicates a blown head gasket. Technician B says that valve clearance that is too much may cause a rough running at idle and a burned valve. Who is correct? A only B only Both A and B Neither A or B

Neither A or B

Two technicians are discussing engine misfires. Technician A says the misfire may be caused by a vacuum leak if it misfires at high rpm but not at idle. Technician B says an ignition misfire will cause your vacuum gauge needle to bounce significantly. Who is correct? A Only B Only Both A and B Neither A or B

Neither A or B

When installing a distributor, Technician A says the distributor must be installed at TDC for number #1 cylinder's exhaust stroke. Technician B says if the distributor is installed on the compression stroke, then the distributor will be 180 degrees off. Who is correct? A Only B Only Both A and B Neither A or B

Neither A or B

The vehicle with the ignition system illustrated above has a no spark condition on cylinders 1 and 4. Technician A says the PCM should be replaced. Technician B says the crankshaft position sensor may be defective.

Neither A or B an ignition module in the PCM would be common to multiple cylinders and would not cause individual cylinder misfires on a waste spark system

What is Voltage?

Pressure pushing electrons through a circuit

Hydrocarbons

Raw Fuel

What is a Voltage Drop?

The loss of voltage in a circuit due to short, heat, bad ground etc. (loss of energy)

A technician is performing a voltage drop on a fuel pump that does operate. When performing the voltage drop test on the Fuel Pump Power Wire the meter displays 12.5V before the fuel pump is turned on. What does this indicate There is continuity through the fuel pump to ground The fuel pump is good An excessive voltage drop on the power wire An excessive voltage drop on the ground wire

There is continuity through the fuel pump to ground

Which of the following is the LEAST LIKELY to cause blue smoke from an engine Worn piston rings Worn valve guides Worn valve seats Worn valve seals

Worn valve seats

Which of the following conditions is the MOST LIKELY to cause weak spark out at the spark plugs? a weak ignition coil low secondary circuit resistance lean air fuel mixtures ignition timing out of adjustment

a weak ignition coil

All of the following are true of a cylinder leakage test EXCEPT: air loss in the intake indicates a bad intake gasket air loss from the oil filler cap indicates worn piston rings a gauge reading of less than 10% indicated acceptable cylinder leakage air loss from the tail pipe indicates an exhaust valve problem.

air loss in the intake indicates a bad intake gasket

All of the following are true of a cylinder leakage test EXCEPT: air loss in the intake indicates a bad intake valve guide air loss from the oil filler cap indicates worn piston rings a gauge reading of less than 10% indicated acceptable cylinder leakage air loss from the tail pipe indicates an exhaust valve problem.

air loss in the intake indicates a bad intake valve guide

V/R

amperage formula

The primary ignition circuit on a vehicle checks good but there is not spark coming from the coil wire. This could be caused by a: bad ignition module shorted primary trigger defective distributor bad ignition coil

bad ignition coil

The primary ignition circuit on a vehicle checks good but there is not spark present at the coil wire. This could be caused by a: bad ignition coil shorted primary trigger defective distributor bad ignition module

bad ignition coil

A restricted exhaust may cause backpressure readings to increase above 1.5 psi at idle increase above 3 psi at high rpm fluctuate between .5-1.5 psi both a and b are correct

both a and b are correct

Three bulbs are connected in parallel. What would be the result if one bulb were to burn out The resistance of the circuit would increase all the bulbs would go out The amperage in the circuit would decrease both a and c are correct

both a and c are correct

When inspecting spark plugs, which of the following could indicate a detonation problem? white insulator tip broken insulator tip wet carbon deposits on the insulator tip black insulator tip

broken insulator tip

A rapidly bouncing needle that steadies as the rpm increases may be caused by worn rings burned valve restricted exhaust vacuum leak

burned valve

While testing the secondary ignition with an oscilloscope, which of the following will cause of excessive burn time in the ignition secondary circuit? a deteriorated rotor button wide spark plug gap carbon tracking on the spark plug boot high resistance in the high tension cables

carbon tracking on the spark plug boot

Oxides of Nitrogen

caused by high pressure and temperature

Voltage Drop

difference in electrical pressure between two points

Voltage

electrical pressure

High carbon monoxide (CO) emissions may be caused by all of the following EXCEPT: fouled spark plug leaking fuel pressure regulator diaphragm leaking fuel injector rich air fuel mixture

fouled spark plug

Cranking Compression readings of 125, 130, 135, 127, 68, and 128 could be caused by: Bent exhaust valve pushrod improperly installed piston rings worn exhaust cam lobe weak valve spring

improperly installed piston rings

Which of the following conditions will require higher secondary ignition circuit voltage: heavy load rich air fuel mixtures when the spark plugs are fouled lean air fuel mixtures

lean air fuel mixtures

A cylinder misfire will cause all the following EXCEPT: rich air fuel mixture High hydrocarbon emissions Damage to the catalytic converter low carbon dioxide readings

low carbon dioxide readings

High carbon monoxide (CO) emissions may be caused by all of the following EXCEPT: rich air fuel mixture leaking fuel pressure regulator diaphragm leaking fuel injector low compression

low compression

A timing belt that has jumped one tooth can cause: low tip in power high engine idle poor vehicle stopping poor drivability at high RPM

low tip in power

Secondary ignition scope patters are being discussed. All of the following will cause burn time to be too short EXCEPT: a deteriorated rotor button wide spark plug gap no dielectric grease on the ignition module mounting surface high resistance in the spark plug wires

no dielectric grease on the ignition module mounting surface

Resistance

opposes current flow

In order for an ignition coil to fire it must have: power and ground power and a pulsing ground pulsing power and constant ground pulsing power and pulsing ground

power and a pulsing ground

If the spark plugs were not easily accessible on an engine which test should a drivability technician perform to evaluate the engine mechanical condition? cranking compression test Leakdown test running compression test relative compression test

relative compression test

Detonation may be caused by all of the following EXCEPT. overly advanced ignition timing lean air fuel mixtures inoperative EGR rich air fuel mixtures

rich air fuel mixtures

All of the following are components in the ignition primary circuit EXCEPT: ignition coil spark plug wire crank sensor ignition module

spark plug wire

All of the following components are part of the primary circuit EXCEPT: ignition coil ignition switch spark plug wire ignition module

spark plug wire

Amperage

the flow of electrons

What is the purpose of coating the back of an ignition module with dielectric silicone grease before installation? to insulate the module from excessive voltage spikes to ensure electrical ground to electrically insulate the module from ground to help dissipate heat from the module

to help dissipate heat from the module

Which of the following is the LEAST LIKELY to be detected by a Cranking Compression test? burnt valve worn rings head gasket failure worn cam lobes

worn cam lobes

A puff of blue smoke at startup may be caused by worn rings burned valve worn valve stem seals rich air fuel mixture

worn valve stem seals