Driveability & Diagnosis Test #1 (Worksheets)
a good fuel pump should be able to supply how much fuel per minute 1/4 pint 1/2 pint 1 pint 0.5 to 0.8 gallon
0.5 to 0.8 gallon
list the 8-step funnel diagnostic procedure
1. verify the problem 2. perform a thorough visual inspection and basic tests 3. retrieve the diagnostic trouble codes (DTCs) 4. check for technical service bulletins 5. look at scan tool data 6. narrow the problem to a system or cylinder 7. determine root cause and repair the problem 8. verify the repair and clear codes
list two advantages of using ethanol fuels
1.) ethanol production is considered carbon neutral, helps to reduce overall emissions and pollution 2.) using an ethanol fuel line E85 can increase power by 5% and the cost is lower to the driver
list two benefits of blending ethanol into gasoline (E10)
1.) raises octane rating by 3 points, making it relatively better, and it raises the volatility 2.) the extra oxygen in the fuel helps convert harmful CO into CO2, helping the enviornment
how much compressed natural gas (CNG) does it require to achieve the energy of one gallon of gasoline?
122 cubic feet
ultra-low sulfur diesel fuel has how much sulfur content
15 ppm
most fuel filters are designed to remove particles larger than 10 microns 20 microns 70 microns 100 microns
20 microns
most port fuel injected engines operate on how much fuel pressure? 3 to 5 psi 9 to 13 psi 35 to 65 psi 55 to 65 psi
35 to 65 psi
the fuel pump inside the fuel tank on a vehicle equipped with GDI produces about what fuel pressure? 5 to 10 PSI 10 to 20 PSI 20 to 40 PSI 50 to 60 PSI
50 to 60 PSI
the fuel injectors used on a GDI system are pulsed on using what voltage 12 to 14 V 50 to 90 V 100 to 110 V 200 to 220 V
50 to 90 V
the fuel injectors operate under a fuel pump pressure of about 35 to 45 PSI 90 to 150 PSI 500 to 2,900 PSI 2,000 to 5,000 PSI
500 to 2,900 PSI
the first fuel filter in the sock inside the fuel tank norm ally filters particles larger than 0.001 to 0.003 inches 0.01 to 0.03 inches 10 to 20 microns 70 to 100 microns
70 to 100 microns
one cylinde of an automotive four-stroke cycle engine completes a cycle every
720 degrees
B20 biodiesel has how much regular diesel
80%
E85 means that the fuel is made from
85% ethanol and 15% gasoline
the specific gravity of diesel fuel is measured in what units
API gravity
most manufacturers of vehicles equipped with diesel engines allow what type of biodiesel
B5
explain why a bulletin search should be performed after DTCs are retrieved
DTCs must be known before searching for the bulletins as the bulletins include information on solving issues within stored DTCs
which sensor has the greatest influence on injector pulse width besides the MAF sensor? IAT BARO ECT TP
TP
removed a flared connection using
a flare-nut wrench
what is a FFV and how is it identified?
a flexible fuel vehicle, capable of running anything from E10 to E85 identified by an emblem, yellow gas cap, label under the hood, or in the VIN number
describe the cetane rating of a fuel
a measure of the ease of how the fuel can be ignited, the opposite of an octane number it determines the fuel's ability to start the engine at lower temperatures, the higher the rating the more easily it's ignited
a flex-fuel vehicle can be identified by emblems VECI VIN all
all
methanol is also called methyl alcohol wood alcohol methyl hydrate
all
which of the following is a possible location for a fuel filter in the fuel line to the injectors in the fuel tank in the carburetor inlet all
all
which of the following is/are true about B20 diesel fuel it can be used in unmodified diesel engines it is 20 percent nonpetroleum it lowers exhaust emissions all
all
which of the following is/are true about flex fuel vehicles FFV uses the same system, no matter what it's running on bi-fuel engine, natural gas and air flow through the intake to the cyliners dedicated NGVs use special natural gas injectors to inject the gas directly into the cylinders all
all
a paper test can be used to check for a possible problem with the ignition system (bad plug wire) a faulty injector on a multiport engine a burned valve
all of the above
fuel injectors can be tested using an ohmmeter a stethoscope a scope all of the above
all of the above
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 all of the above
all of the above
which of the following can result from an intake manifold air leak rough idle higher idle speed flat spot on acceleration
all of the above
winter blend gasoline vaporizes more easily than summer-blend gasoline has a higher RVP can cause engine driveability problems if used during warm weather
all of the above
the high-pressure fuel pump pressure is regulated by using an electronic pressure-control valve a vacuum-biased regulator a mechanical regulator at the inlet to the fuel rail a non-vacuum-biased regulator
an electronic pressure-control valve
a fuel pump was measured for current draw and amperage exceeded factory specifications. this can be caused by a clogged fuel filter restricted fuel line defective fuel pump any of the above
any of the above
ethanol can be produced from what products switchgrass corn sugarcane any of the above
any of the above
where is the fuel-pressure regulator located on a vacuum-biased port fuel-injection system? in the tank at the inlet of the fuel rail at the outlet of the fuel rail near or on the fuel filter
at the outlet of the fuel rail
a fuel pressure gauge can be installed at the schrader valve on TBI looped port fuel injection both neither
both
tech a says that some dual-fuel engines burn an AF mix of natural gas and diesel. tech b says that a bi-fuel engine is one that can be switched to burn on one of two different fuels. who is right? tech a tech b both neither
both
tech a says that the computer on some fuel injection systems pulses several injectors at the same time. tech b says that the computer on some fuel injection systems pulses each fuel injector individually. who is right
both
tech a says that the research octane number is higher than the motor octane number. tech b says that the octane rating posted on fuel pumps is an average of the two ratings. who is correct?
both
technician a says that the first step in the diagnostic process is to verify the problem. technician b says the second step is to perform a thorough visual inspection. who is correct?
both
the throttle plate can be held open by carbon and gum deposits on TBI engines PFI engines
both
which of the following fuels does a flexible fuel vehicle use ethanol gasoline
both
which of the following is/are true about alcohol and gasoline? alcohol fuels carry more water than straight gasoline alcohol fuels have a higher octane number than gas both neither
both
fuel lines are constructed from seamless steel tubing nylon plastic copper and/or aluminum tubing both a & b
both a & b
a lack of power from an engine equipped with GDI could be due to noisy injectors carbon on the injectors carbon on intake valves both carbon on injectors and intake valves
both carbon on injectors and intake valves
a fuel pump is being replaced for the third time. tech a says that the gasoline could be contaminated. tech b says that the wiring to the pump could be corroded. who is correct?
both tech a & tech b
tech a says that the fuel pump relay is usually controlled by the PCM. tech b says that a TBI injector squirts fuel above the throttle plate. which is correct?
both tech a & tech b
technician a says that spark knock, ping, and detonation are different names for abnormal combustion. tech b says that any abnormal combustion raises the temperature and pressure inside the combustion chamber and can cause severe engine damage. who is correct?
both tech a and b
fuel injection service is being discusses. tech a says that the throttle plate(s) should be cleaned. tech b says that the fuel rail should be cleaned. who is correct?
both tech a and tech b
the fuel pressure dropped rapidly when the engine is turned off. tech a says that one or more injectors could be leaking. tech b says that a defective check valve in the fuel pump could be the cause. who is correct?
both tech a and tech b
which of the following would be more likely to experience vapor lock in hot weather fuel injection carburetor
carburetor
what rating of diesel fuel indicated how well a diesel engine will start
cetane rating
list the three basic things that an engine needs to run
compression, spark, fuel
all of the following are electronic fuel injection systems except
continuous
the amperage draw of an electric fuel pump is higher than specified. all of the following are possible causes except corroded electrical connections at the pump motor clogged fuel filter restriction in the fuel line defective fuel pump
corroded electrical connections at the pump motor
which of the following is most likely to result in a broken, unburned piston
detonation
where is the fuel injected in an engine equipped with GDI? into the intake manifold near intake valve directly into the combustion chamber above the intake port in the exhaust port
directly into the combustion chamber
who/what is the best resource on the symptoms of the problem?
driver/operator
vapor lock can occur as a result of excessive heat near fuel lines if a fuel line is restricted during both a and b during neither a or b
during both a and b
what can be used to measure the alcohol content in gasoline graduated cylinder electronic tester scan tool
either a or b
in a typical port fuel injection system, which injectors are most subject to becoming restricted any of them equally the injectors at the end of the rail on a returnless system the injectors at the bends in the rail either b or c
either b or c
what component pulses the fuel injector on most vehicles? electronic control unit (ECU) ignition module crankshaft sensor both b and c
electronic control unit (ECU)
which type of port-injection system uses a fuel temperature and/or fuel-pressure sensor? all port fuel-injected engines TBI units only electronic returnless systems demand delivery systems
electronic returnless systems
e-diesel is diesel fuel with which additive
ethanol
producing liquid fuel from coal or natural gas usually uses which process? syncrude p-series fisher-tropsch methanol to gasoline (MTG)
fisher-tropsch
the diesel injection pump is usually driven by a gear off the camshaft belt of the crankshaft shaft drive off the crankshaft chain drive off the camshaft
gear off the camshaft
which part should be removed to test cylinder compression on a diesel engine? injector intake valve rocker arm and stud glow plug glow plug or injector
glow plug or injector
most diesel fuel is what grade
grade #2
all overhead valve engines... use an overhead camshaft have the valves located in the cylinder head operate by the two-stroke cycle use the camshaft to close the valves
have the vales located in the cylinder head
how is diesel fuel ignited in a warm diesel engine? glow plugs heat of compression spark plugs distributorless ignition system
heat of compression
which diesel system supplies high-pressure diesel fuel to all of the injectors all of the time? distributor inline high-pressure common rail rotary
high-pressure common rail
the three phases of diesel ignition include glow plug ignition, fast burn, slow burn slow burn, fast burn, slow burn ignition delay, rapid combustion, controlled combustion glow plug ignition, ignition delay, controlled combustion
ignition delay, rapid combustion, controlled combustion
which method of blending ethanol w gasoline is the most accurate in line sequential splash all equally
in line
Which diesel injection system requires the use of a glow plug? indirect injection (IDI) high-pressure common rail direct injection distributor injection
indirect injection (IDI)
which type of diesel injection produces less noise? indirect injection (IDI) high-pressure common rail direct injection distributor injection
indirect injection (IDI)
the avoid problems with the variation of gasoline, all government testing uses ___ as a fuel during testing procedures MTBE indolene xylene TBA
indolene
if it is tripped, which type of safety device will keep the electric fuel pump from operating rollover valve inertia switch anti-siphoning valve check valve
inertia switch
avoid topping off the fuel tank because
it can saturate the charcoal canister
what does the term "stoichiometric" mean? and what is the value for gasoline-air mixtures?
it means a chemically perfect combination, the ideal mixture of gas and air that allows all of the fuel to combine with all of the air, burning completely. 14.7:1
which mixture is most likely to cause a driveability problem?
lean
what is the specific gravity of diesel fuel and how is it measured?
measured in units of API gravity, which is an arbitrary scale expressing density of liquid products, calibrated in terms of degrees API. it's measured using a hydrometer in API gravity units
which alcohol is dangerous
methanol
tech a says that in going to high altitudes, engines produce lower power. tech b says that most engine control systems can compensate the AF mixture for changes in altitude. who is correct?
neither
tech a says that the speed density fuel injection system uses an airflow sensor. tech b says that an air density system uses a manifold pressure sensor
neither
tech a says that to start a fuel-injected car, the accelerator should be depressed once. tech b says to start an engine with a carburetor, do not touch the accelerator pedal until the engine is running. who is right?
neither
tech a says that exploding fuel pushes the piston down in the cylinder when the ignition timing is correct. tech b says that exploding fuel pushes the piston down in the cylinder during normal combustion. who is right?
neither a nor b
tech a says that glow plugs are used to help start a diesel engine and are shut off as soon as the engine starts. tech b says that the glow plugs are turned off as a flame is detected in the combustion chamber. who is correct?
neither tech a or tech b
what prevents the fuel pup inside the tank from catching the gasoline on fire? electricity is not used to power the pump no air is around the motor brushes gasoline is hard to ignite in a closed space all of the above
no air is around the motor brushes
list 3 things that should be checked as part of a thorough visual inspection
obvious problems (fuel leaks, disconnected hoses, unusual noises) look for evidence of previous repairs oil level and condition
how many rotations of the crankshaft are required to complete each stroke of a four-stroke cycle engine
one-half
throttle body fuel injection systems use what type of injector driver
peak and hold
what are the two types of abnormal combustion and how are they different?
pre-ignition: before the spark plug fires, caused by hot spots, wrong spark plugs, loose spark plugs detonation: after the plug fires, caused by slow normal combustion
liquefied petroleum gas (LPG) is also called
propane
which is the most widely used alternative fuel
propane
what color is diesel fuel dyed if it is for off road use only
red
dampeners are used on some fuel rails to increase the fuel pressure in the rail reduce (decrease) the fuel pressure in the rail reduce noise trap dirt and keep it away from the injectors
reduce noise
why are some fuel rails rectangular in shape? increases fuel pressure helps keep air out of the injectors reduces noise increases the speed of the fuel through the fuel rail
reduces noise
air and fuel mixed at a ratio of 9:1 is considered to be
rich
By asking the 5 whys, a technician tries to get to the ____ cause of the problem
root
port fuel injection systems generally use what type of injector driver
saturated switch
which type of fuel injection do most new vehicles use
sequential port or none of the above
which fuel-injection system uses the MAP sensor as the primary sensor to determine the base pulse width? speed density mass air flow demand delivery mechanical returnless
speed density
the most efficient way to use a diagnostic aide (trouble tree) is to
start at the beginning and follow each step exactly
what type of device is used in a typical idle air control? DC motor stepper motor pulsator-type actuator solenoid
stepper motor
which mode of operation results in a richer air-fuel mixture near the spark plug? stoichiometric homogeneous stratified knock protection
stratified
what is the difference between summer blend and winter blend gasoline?
summer blend gasoline has a lower volatility. winter blend has a higher volatility to help cold starting
tech a says a rich mixture does not have enough air. techn b says a lean mixture has too much fuel. who is correct?
tech a
tech a says that a crankshaft determines the stroke of an engine. tech b says that the length of the connecting rod determines the stroke of an engine. who is correct?
tech a
tech a says that when there is a righ AF mixture, the O2S will give a signal that is higher than 0.5 volt. tech b says that if there is a low-voltage signal coming from the O2s, the computer will drive the system rich. who is right
tech a
tech A says to check spark plug by grounding the spark plug on the valve cover. tech b says the paper test could indicate a mechanical problem. who is correct?
tech b
tech a says one should first seek opinions of other technicians. tech b says one should perform diagnostic tests rather than seek opinions. who is correct?
tech b
tech a says that a car with a rich AF mixture will surge on the highway. tech b says that a lean mixture can result in burned parts. who is correct
tech b
tech a says that the port fuel injection injectors operate using five volts from the computer. tech b says that the sequential fuel injectors all use a different wire color on the injectors. who is correct?
tech b
the vacuum hose from the fuel pressure regulator was removed from the regulator and gasoline dripped out of the hose. tech a says that this is normal and that everything is okay. tech b says that one or more of the injectors may be defective, causing the fuel to get into the hose. who is correct?
tech b
tech a says that the fuel pump modules are spring loaded so that they can be compressed to fit into the opening. tech b says that they are spring loaded to allow for expansion and contraction of plastic fuel tanks. which technician is correct?
tech b only
which item is not important to know before starting the diagnosis of an engine performance problem? list of previous repairs type of gasoline used brand of engine oil used the temp of the engine when the problem occurs
the brand of engine oil used
the high-pressure fuel pups used in GDI systems are powered by electricity (DC motor) electricity (AC motor) the camshaft the crankshaft
the camshaft
what does the (R + M) / 2 gasoline pump octane rating indicate?
the equation displays that the octane rating is the average of the two basic methods used to rate gasoline for anti-knock properties, the research and motor methods
when a fuel injected engine is shut off
the fuel supply line remains pressurized
describe how elevation changes the volatility and octane requirement for gasoline
the higher the elevation, the less dense the air is. therefore, the engine cannot take in as much air, lowering the octane requirement. it also changes the volatility, as high altitudes allow fuel to evaporate more easily, reducing the volatility of gasoline
describe the cloud point of diesel fuel
the low-temperature point when the waxes in diesel fuels form crystals that clog the fuel filter. it must be below the lowest outside temperature to prevent filter plugging
what is Reid vapor pressure
the pressure of vapor above the fuel when the fuel is at 100 oF
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
the coolant flow through the radiator is controlled by the... size of the passages in the block thermostat cooling fan(s) water pump
thermostat
why is a vacuum line attached to a fuel-pressure regulator on many port-fuel injected engines? to draw fuel back into the intake manifold through the vacuum hose to create an equal pressure drop across the injectors to raise the fuel pressure at idle to lower the fuel pressure under heavy load conditions to help improve fuel economy
to create an equal pressure drop across the injectors
burned spark plugs can result from operating with a fuel system that is too rich too lean either neither
too lean
a GDI system can be used to start an engine without the need for a starter True or False
true
biodiesel is regular diesel fuel with vegetable oil added
true
some engines that use a GDI system also have port injection True or False
true
using the ethanol enhanced or reformulated gasoline can result in reduced fuel economy. t or f
true
a SOHC V8 engine has how many camshafts
two
What is the first step in the diagnostic process?
verify the problem
which step should be performed last when diagnosing an engine performance problem? checking for any stored DTCs checking for technical service bulletins performing a thorough visual inspection verify the repair
verify the repair
what are the two most important properties of gasoline?
volatility and octane rating
which test is the best indicator of a fuel pump problem pressure volume compression aspiration
volume
glow plugs should have high resistance when ___ and lower resistance when ___ cold/warm warm/cold wet/dry dry/wet
warm/cold
what fuel system component is used in a vehicle equipped with a diesel engine that is seldom used on the same vehicle when it is equipped with a gasoline engine? fuel filter fuel supply line fuel return line water-fuel seperator
water-fuel seperator
what clogs fuel filters when the temp is low on a diesel fuel vehicle
wax
what is vapor lock?
when liquid gasoline vaporizes under high temperatures, causing air bubbles to form in fuel. causes a lean condition and prevents proper operation
