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159 Cards in this Set
- Front
- Back
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Alchohol weighs ____ gasoline |
Less than |
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All of following are aromatic hydrocarbons except |
Kerosene |
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All of these statements about excessive alcohol and gasoline are correct except |
Can cause a rich fuel mixture |
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All of the following are emission related characteristics a diesel fuel except |
Lower nox |
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All of the following are factors that cause knock except |
Decrease compression ratio |
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All the following statements are correct except |
Tetraehyl lead is added to gas to decrease vapor press |
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All of the following statements concerning e85 automotive fuel are true except |
E85 is more fuel efficient |
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A LP propane power vehicle stores as fuel in pressurized tanks at approximately_____ psi |
200 |
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an engine is being diagnosed for a lean running condition technician a check for air leaks in intake technician b check for alcohol in the fuel who is correct |
Both a and b |
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Crude oil is separated into its basic chemical compounds by ____ in this process the crude oil is heated to about 1200 degrees Fahrenheit and vaporized different chemical compounds can dance at different temperatures as the vapor passes through a cooling tower |
Fractional distillation |
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Diesel engines are being discussed technician a says diesel fuel contains less energy than gas technician b says diesel engines produce more torque than gasoline who is correct |
B |
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Excessive alcohol in the fuel may cause |
All answers |
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fuel additives are being discussed technician a says oxygenates to gasoline increases fuel economy technician b says adding 10% ethanol to gasoline May boost the octane rating 2.5 to 3 points who is correct |
B |
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Gasoline volatility is being discussed tech a says gasoline blended for summer use is more volatile than winter gasoline tech b says that high altitude areas feels must be blended to hire volatility |
B only |
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How can you identify a flex fuel vehicle |
Clover leaf symbol on exterior or interior of vehicle |
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while discussing the reasons why that used to e85 gasoline is good for consumers tech a says is produced in the United States occur reduce our reliance on foreign oil technician b says an engine fuel consumption is greatly reduced who is Colette |
A only |
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Hydrogen fuel vehicles are being discussed tech a says H2 can be made from natural gas tech b says hide your day can be made from water who is correct |
Both |
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If a flex fuel vehicle has half a tank of e85 on board in the driver then fills the tank up with gasoline what will happen |
System will automatically adjust to run normal |
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in the past limo sulfur content diesel is 500 parts per million the current standard for low sulfur diesel fuel allows a maximum of_____of sulfur in the fuel |
15ppm |
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Methanol can be made from |
All the above |
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Menthol is not commonly used as an automotive fuel because |
Highly corrosive |
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Most diesel fuel currently available at the pump has a cetane rating of |
42 to 55 |
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Technician a says piezo material is a type of Crystal that rapidly shrinks when is exposed to electrical current technician b says piezo material shrinks very slowly when current to it is stopped who is correct |
Neither a nor b |
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Tech a says the reform unleaded gasoline produces a leaner air fuel mixture technician b says the rfg generates more carbon dioxide who is correct |
A |
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tech a says that the use of methanol and internal combustion engines has declined over the years technician b says the use of mtbe as gasoline additive has declined over the years who is correct |
Both |
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tech a says white smoke in the exhaust of a diesel engine can be a result of a misfire and a warm engine technician b says blue smoke in the exhaust of the diesel can be caused by scored cylinder walls who is correct |
Both |
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While diagnosing a diesel answer drivability problem technician a says the scan tool data is similar to the available for gasoline engine all diesel engine troubleshooting procedures are unique technician b says a cylinder balance check can be made by checking the resistance of the engines glow plugs who is correct |
B |
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Octane ratings are being discussed tech a says most modern engines are designed to use regular grade gas tech b says to use high octane gasoline only when the engine was designed to use it |
Both |
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Which of the following chemicals is commonly added to gasoline to increase its octane rating |
Ethanol |
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All the answers with non hardened valve seats made need a_____substitute added to gasoline or ethanol blends to prevent premature valve seat wear |
Lead |
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Which of the following statements about hydrogen is not true |
It cost less to produce hydrogen then it does produce gas |
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Tech a says number one diesel fuel is the most popular and widely distributed tech b says number 1 diesel fuel is blended with number two to improve starting in cold weather who is correct |
Both |
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Tech a says a motor converts electrical energy into mechanical energy tech b says an engine converts chemical energy into mechanical energy who is correct |
B only |
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Tech a says and 87 octane fuel is a brand of 87% octane in 13% ethanol tech b says 87 octane fuel will experience detonation in a test engine at the same temperatures and pressure as a simple feel brand of 87% isooctane and 13% heptane who is correct |
B only |
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two cases blending 10% ethanol into gasoline results in an increase of 2.523 octane points technician b says ethanol is highly corrosive and highly toxic who is correct |
A only |
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tech a says large low speed industrial Diesel's require high quality in high volatile fuel because they cannot tolerate excessive carbon deposit that results from low volatile fuel tech b says the small high speed diesel engines found in passenger cars are relatively unaffected by carbon deposits and can run on low-quality field |
Neither |
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Technician a says leave ratios of 15 to 1 and 16 to 1 provide the best fuel economy tech b says which mixtures have a ratio below 14.721 and provide more power from the engine for greater fuel consumption who is correct |
Both |
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Tech a says diesel engines consume less fuel per mileage than a gasoline engine of the same size tech b says diesel engines provide more torque than a gasoline engine of the same size who is correct |
Both |
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Tech a says the biggest disadvantage of using CNG as a feel is that this large amount space occupied by fuel cylinders limit the driving range of the vehicle tech b says by fuel vehicles are equipped to store both CNG and gas and will run on either who is correct |
Both |
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tech a says there is less heat energy in high octane gas and therefore less power is generated during combustion tech b says using a higher octane gas that required will not produce more power and less engine has a knock sensor that allows assistant to adjust Nish timing to take advantage of the house. See who is correct |
Both |
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Ideal air fuel the stoichiometric ratio for a gas engine is approximately _____ pounds of air mixed w pound of gas |
14:1 |
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The volatility of gas affects all the following performance characteristics or driving conditions except |
Fuel line freeze up |
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Using gas with high levels of sulfur can cause |
All answrrs |
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What cam is added cities in late the gas as anti-icing agents prevent fuel line freeze-up in cold weather |
Isopropyl alcohol |
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Which of the following are characteristics of Burning LP gas |
All answers are correct |
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Which of the following is not a major factor affecting fuel performance |
Nitrogen content |
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Which of the following is not an advantage of biodiesel fuel |
Less expensive to make than petroleum based oil |
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while discussing common rail fuel injection system technician a says they have 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 |
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Which of the following is an effect of adding alcohol to gas |
Both of reduces the chance of fuel line freeze-up and it decreases carbon monoxide emissions |
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Which of the following is considered natural gas |
Propane |
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Which of the following statements about P-Series feel is not true |
Unlike ethanol and methanol it cannot be mixed with gas |
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A fuel system that runs 35 to 50 psi should draw around ____ amps of current |
4-9amps |
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A high fuel pressure reading is typically caused by a faulty fuel ____ |
Pressure regulator |
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A loss of residual fuel pressure immediately after engine shutdown could cause _____ |
Hard starting |
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A no start no fuel pressure condition is being diagnosed when a test light is connected to the pump positive terminal there is no voltage when the engine is cranked by the starter what could cause the problem |
Defective fuel pump relay |
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Unplug fuel filter would cause ______ |
All answers are correct |
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a vehicle's been diagnosed with a low fuel pressure problem a fuel pump current test reveals higher than normal current flow tech a says the vehicle may have a clogged fuel filter tech b says the fuel pump ground wire may be loose or corroded who is correct |
Tech a |
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A vehicle with a leaking nylon fuel supply line is being repaired tech a says that the nylon fuel line with a section of double wall steel fuel line using short length of rubber fuel hose and screw clamps to connect to the fuel filter and fuel tank to steal mine can be replaced tech b says use a OEM nylon fuel line assembly who is correct |
B |
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Girl line fittings are being are being discussed tech a says that o rings are used on some fuel line fittings tech b says that clamps are used on some systems who is correct |
Both |
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Fuel lines are being discussed tech a says when installing flexible tubjbg always use new clamps tech b says ordinary rubber hose may be used to replace a kinjed steel fuel line who is correct |
A |
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Fuel pressure are being discussed tech a says high fuel pressure can be caused by a defective pressure regulator tech b say low fuel pressure can be caused by a defective pressure regulator who is correct |
Both |
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Fuel tanks may be constructed of all the following except |
Brass |
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Gas cap testing is being discussed tech a says the tester applies twenty inches of vacuum to the cap and measures it's rate of leakage tech b says if the wrong adapter was used the cap will fail the test even if it's good |
B |
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If twenty in he's of vacuum is applied to the fuel pressure regulator whole the fuel pump is running the fuel pressure should ____ |
Decrease |
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In Chrysler efi systems the asd relationship automatic shutdown controls the power to the ______ |
All answers are correct |
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ObdII evaporative system integrity testing is being discussed tech a says the integrity check is done by creating a vacuum in the tank and measuring how well it hold the vacuum tech b syas the fuel tank pressure ftp sensor is a transducer that conversation the absolute pressure in the fuel tank into an input for the pcm who is correct |
Both a and b |
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On a modern common rail diesel di direct injection system fuel pressure is typically ____ psi |
26000 |
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Residual fuel pressure is being discussed tech a says remove the fuel filter hose and apply compressed air to the fuel line to push the residual fuel back into the fuel tank tech b says to relieve the resudyal pressure by connecting a fuel gauge with a bleed to the shrader valve who is correct |
B |
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Tech a connect a fuel pressure gauge to the Schrader valve on fuel rail technician b connects the gauge to the fuel lines by inserting a tee adapter between the fuel filter and the fuel rail who |
Both |
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Tech a says a pressure relief valve opens if the fuel supply line is restricted a pump prevents fuel from draining out of the fuel system and back into the fuel tank this helps holds residual pressure in the fuel lines after the pump I turned who is correct |
Both a and b |
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Tech a says low fuel pressure can be caused by a restricted fuel filter tech b says low fuel pressure can be caused by a kinjed fuel return line who is correct |
A |
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Tech a says on some vehicles the fuel pressure is monitored by a fuel rail pressure sensor and the utput of the fuel pump is controlled by the PCM through pulse width modulation tech b says all fuel pump on late model vehicles are controlled by the pcm according to received on the can bus and other specific sensors who is correct |
Both a and b |
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Tech a says the best method for permanently solving a leaking a metal fuel tank is to replace the tank technician b says a leaking plastic fuel can sometimes be repaired |
Both |
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Technician a says the gas cap is equipped with a pressure release valve that opens if there is excess vapor pressure in the fuel tank this prevents tank balooning tech b says the gas cap is equipped with a vacuum relief valve that opens if there is an excessive amount in the fuel tank this prevents tank collapse who is correct |
Both a and b |
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Technician a says the inertia switch has a reset button that much be depressed before the pump will operate again technician b says the inertia switch is triggered by the abs control module |
A |
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The first step in removing a fuel tank is to _____ |
Remove the negative battery cable |
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The fuel filter on a modern car is typically mounted ____ |
Under the car |
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The fuel pressure regulator on regurnlezs fuel system is located |
Inside the fuel tank |
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What exyubguyisv r should be used on gas fires |
Inside the fuel tank |
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When draining a fuel tank tech a drains the fuel into plastic antifreeze containers then caps them tightly to prevents leaks. Tech v drains the fuel into approved gasoline storage containers who is correct |
B only |
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Which of the following is a typical fuel filter replacement interval |
30000 |
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Which of the could not cause the fuel pressure to drops off quickly after the engine and ignition are turned off |
Restricted fuel filter |
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A cpi central multiport injection system for a six cylinder eng has _____ |
All answers correct |
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I feel injection system that has a map sensor manifold absolute pressure to determine the amount of air entering the engine is called a____-type injection sysytem |
Speed density |
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A sudden increase in TP voltage tells the PCM to ____ to prevent hesitation |
Momentarily enrich mixture |
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An o-ring at the base of a fuel injector_____ |
All answers correct |
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Each feel injector has a_____-wire connector |
2 |
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Feel injector firing is being discussed tech a says SFI systems control each injector separately so that if I've just before the intake valve opens tech b says sequential injectors fire more accurate than multi-port systems who is correct |
Both are correct |
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Fuel injectors are |
Both top feeding devices and bottom fuel feeding devices |
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Fuel injectors may be controlled ____'_ |
All answers correct |
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Fuel trim is being discussed tech a says a positive fuel trim value means the PCM detects a lean mixture and is increasing the pulse-width to add more fuel to the mixture tech b says ltft long-term fuel trim is erased when the ignition is turned off who is correct |
A only |
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IAC idle air control valves are operated by a _____ |
Stepper motor |
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If the throttle is held wide open while the engine is cranked over by the starter motor the fuel management system with enter ____ mode |
Clear flood |
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In a gdi gasoline direct injection system the tip of the injector is located ____ |
Inside the combustion chamber |
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In closed loop the PCM adjusts the pulse width according to inputs from a variety of sensors but primarily the ___' |
O2s oxygen sensor |
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In most tbi systems the fuel pressure is maintained @ ___ |
10-25 psi 70-172kpa |
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Only ____ meets the requirements of obd II regulation |
SFI sequential fuel Injection |
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Tech a says a throttle body mat house one fuel injector tech b says a throttle body may house two fuel injectors who is correct |
Both a and b |
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Tech a says an sfi is more efficient than a mpi injection because fuel is injected only when the intake valve an open so the fuel can't codense when the intake valve is closed tech b says an mpi injection system can shut down the injector for a misfiring cylinder preventing catalytic converter overheating who is correct |
A only |
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Tech a says an air fuel ratio sensor responds to minor changes in the air fuel mixture tech b says that when an air fuel sensor is used on an obdII VEHICLES both the upstream and downsteam sensor must be air/fuel ratio type sensors |
A |
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Technician a says n order to meet obd standards diesel control systems use many of the same inputs as a gasoline engine (such as the map, iat, maf, tp, ckp and cmp) technician b says the pressure in the fuel rail of a modern common tail diesel engine can range from 2000 psi 138 bar to 25000 psi 1724 bar. Who is correct |
Both a and b |
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Tech a says piezoelectric injectors rely on stacked crystals that expand when a voltage is applied tech tech b says piezoelectric injectors are slower acting than solenoid-type injectors |
A only |
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Tech a says pulsation dampers reduce the pressure pulsation caused by rapid opening and closing if fuel injectors tech b says the damper helps to reduce fuel noise and maintains press during eng cool down |
Both a and b |
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Tech a system the air fuel ratio of a GDI gasoline direct injection engine can be as high as 60 to 1 tech b says because the the air-fuel ratios are so lead GDI engines require lower compression ratios to prevent detonation who is correct |
A only |
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Tech a says the computer used the tp sensor and oxygen sensor signals to determine the amount of air entering the engine in a speed density system who is correct |
Neither a nor b |
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Tech a says the fuel pressure regulator in pfi system senses manifold vacuum and continually adjusts the fuel pressure to maintain a constant pressure drop across injector tech b says press regulator in a pfi system is designed to provide a constant pressure to the fuel injector throughout the range of engine loads and speeds who is correct |
Neither a and b |
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Technician a says the oxygen sensor O2S detects misfires by monitoring the amount of unburned fuel in the exhaust system tech b says a heating element inside the sensor allows the sensor to reach op temperature quickly and to maintain it's temperature during period of idling or low engine load who is correct |
B |
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Tech a says the vacuum hose in the fuel pressure regulator or a PFI system is connected to the intake manifold tech b says the fuel pressure regulator of a TBI injection system doesn't need a vacuum hose to regulate pressure because the injection system doesn't need a vacuum hose to regulate pressure because the injectors are located above the throttle plate where the air pressure is constant who is correct |
Both |
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Tech a says throttle by wire systems etc eliminate the need for a cruise control actuator tech b says etc also allows the pcm to be more effective when limited engine and vehicle speeds who is correct |
Both a and b |
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Tech a says when ECT sensor detects low engine temperature the PCM decreases the injection Pulse width tech b says when The tp sensor detects a sudden increase in throttle angle the PCM increases the injectors pulse width who is correct |
B only |
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The fuel pressure regulator can be located |
All answers are correct |
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The longest injector pulse width occurs during |
Cold starting |
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The most important sensor in the fuel management system is |
Ckp |
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The throttle body of a gift fuel injected engine may include any of the following components except |
O2s |
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Typical fuel injector pulse width range from ____ to ______ ms |
1;10 |
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Which of the following is NOT a component of a throttle by wire system? |
IAC motor |
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Which of the following isnt an op mode of a GDI gasoline direct injection engine |
Idle mode |
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Which of the following is not representative if sequential fuel injection. Systems |
All injectors receive the same pcm commands simultaneously |
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Which sensor synchronizes the firing of the injector and determine when piston number 1 on compression stroke |
Cmp camshaft position |
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While cranking. Fuel injected engine and holding the accelerator to the wide open throttle position. The a/f mixture will be |
Lean |
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While discussing pfi systems tech a says the PCM provides the proper a/f ratio by controlling the fuel pressure tech b says the PCM provides the proper a/f ratio by controlling the injector pulse width who is correct |
B only |
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While discussing central port injection cpi tech a says the poppet nozzles are opened by the computer tech b says the poppet nozzles are opened by fuel pressure who is correct |
B |
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A rich a/f mixture is being discussed tech a says oxygen content in the exhaust will be high tech says the O2 sensor volt will be high who is correct |
B |
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A technician is testing a fuel injection system with a scan tool while the engine is running in closed loop he loosens a vacuum hose to create a small vacuum leak initially the stft rise and the ltft remains unchanged after a few minutes the stft returns. To near zero and the ltft rises this proves that _____ |
The system is working normally |
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A vehicle with excessively high fuel pressure is being diagnosed test a says the problem could be a restricted fuel tech b says the problem could be a shorted closed fuel pump relay who is correct |
A |
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A vehicle with excessively high fuel pressure is being diagnosed tech a says the problem could be a restricted fuel return line tech b says the problem could be a shorted closed fuel pump relay who is correct |
A |
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In app accelerator pedal position. Sensor is found in vehicles with ____ |
Throttle by wire |
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An injector balance test requires an injector pulse tester and a ____ |
Lab scope |
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A oxygen sensor much heat up to approx _______ before functioning |
600 deg f |
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Fuel trim is being discussed tech a says a +12 percent ltft value indicates that the system is running 12% richer than normal |
Neither |
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If liquid gas is found in the fuel pressure regulator vacuum |
Replace the pressure regulator |
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If the iac counts are below 16 fully warmed up engine there may be a problem with a(n) |
Vacuum leak |
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Injector cleaning is being discussed tech a use a wire brush to clean the tips of the injectors tech b soaks the injector in cleaning solvent who is correct |
Neither |
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Most heated oxygen sensors have _____ wires connected to them |
4 |
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Operation of an O2 sensor is checked with a(n) _____ |
Voltmeter |
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Preliminary checks are being discussed tech a says to run specific fuel injection test first tech b says most driveability concerns are caused by PCM related problems who is correct |
Neither |
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Quick test to a gm hot film mass airflow meter on a engine with idling problems are being perform TECH A taps on the meter with a plastic mallet TECH B unplugs the meter who is correct |
Both a and b |
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Short term and long term fuel trim reading are being discussed tech a says a scale of 0-255 is used technician b says percentage is used who is correct |
B only |
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Tech a checks gdi injectors with a pulse tester tech b test gdi I Hector's with an ohmmeter who is correct |
Tech b |
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Tech a says a defective injector may cause cylinder misfiring at idle speed technician b says restricted injector tips may result in Acceleration stumble who is correct |
Both a and b |
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Tech a says a rich af ratio may be caused by low fuel pump pressure tech b says a rich af ratio may be caused by a defective ect who is correct |
B |
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Tech a says a small leak in the air duct between the maf and the throttle body will not cause a driveability problem tech b says a small Intake manifold leak in a speed density system will not cause a driveablity |
B |
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Tech a says an intake manifold vacuum leak may cause a high idle speed tech b says a dirty IAC bypass passage will not cause the idle speed to be below specs who is correct |
A |
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Tech a says higher than normal idle speed maybe be caused by an ac switch that is always closed tech b says higher than normal idle speed may be caused by a defective engine coolant temperature sensor who is correct |
Both |
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Tech a says if a lean condition caused by a vacuum leak, restricted injectors, dirty may, clogged fuel filter, bad fuel pump exists, the ltft will have a negative number tech b says when the O2 sensor has a rich signal the stft goes lean to adjust the air fuel ratio who is correct |
B |
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Tech a says the iac counts should change when the a/c compressor is turned on and off tech b says if the scan tester indicates zero iac counts there may be an open circuit between the PCM and the iac motor who is correct |
Both a and b |
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Tech a says the tprel pid us the ocns closed throttle reference voltage tech b says an idle trim procedure should be done whenever a part of the iac statement is replaced or a repair is made to something that affects idle speed who is correct |
Both a and b |
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Tech a says throttle body cleaner may be used to clean the iac motor internal components tech b says on some vehicle iac motor damge can occur if the pintle is cleaned with throttle body cleaner who is correct |
B |
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The activity of an O2 sensor is beT monitored with a |
Lab scope |
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The voltage signal from most O2 sensors varies between _____ & ______ volts |
0, 1 |
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Vacuum leak in speed density systems can be verified by watching the _____ on a scan tool |
O2s sensor cross-counts |
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What could a leak in the fuel pressure in the pressure regulator or the fuel pump check valve that allows the fuel pressure to slowly bleed down after engine shutdown cause |
Hard starting |
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When cleaning the injectors with a pressurized injector cleaner prior to starting the engine ______ |
All answers |
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Which of the following components can cause excessively high pressure in a returnless fuel delivery |
All |
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Which of the fooling sensors is used to modify the engine air fuel mixture based on oxygen in the exhaust |
O2 sensor |
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Which of the following should not be used to lubricate injector orings |
Silicone grease |
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Which of the following should be checked before proceeding with specific fuel injection an electronic control testing |
All answers are correct |
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Which of the following week not cause the fuel trim to be out if range |
Faulty iac motor idle air control |
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Which of the following wouldnt cause the fuel pressure to drop to zero immediately after engine shutdown |
Leaking pressure regulator vacuum line |
