Fuel Systems Flashcards
A rich mixture can cause?
- wasted/Unburnt fuel
- spark plug fowling
- rough running engine
- loss of power
- engine failure
A lean mixture can cause?
- overheating
- backfiring
- detonation
- rough running engine
- loss of power
- engine failure
Can gasoline explode on its own?
No it requires a mixture of air for the explosion to occur
What is the normal amount of air/fuel mixture ratio?
- 7 parts air to 1 part fuel
14. 7:1
Describe a fuel pump.
Provides fuel pressure and volume to the fuel injection system
Describe the fuel gauge sending unit.
Provides fuel level info to the body control module and fuel gauge.
Where can a fuel gauge sending unit be located?
Can be located in the fuel pump assembly or as a separate unit
Describe the fuel pressure regulator.
Controls the maximum pressure of fuel sent to the fuel injection system.
Where can the fuel pressure regulator be located?
Can be part of the fuel pump assembly or located on the fuel rail.
Describe the fuel filter.
A filter in the fuel line that screens out dirt and rust particles from the fuel.
Where can the fuel filter be located?
Can be part of the fuel pump assembly or in the line on the frame.
Describe the fuel pickup filter.
A fuel filter attached to the end of an electronic fuel pump to pre-filter out any contaminants from the fuel.
Describe the fuel pump assembly.
A drop in unit, usually containing the: fuel pressure regulator, fuel level sending unit, electrical connections, Evan and fuel connections, fuel filter, and fuel pickup filter.
Describe the fuel tank
A safe container to store the fuel in an automobile. Some have an elective bladder system to prevent any vapour loss.
What can the fuel tank be made out of?
Plastic or metal
What measures the fuel tank pressure?
ECM through sensors to make sure that no fuel is being vented to the atmosphere.
What does ECM stand for?
Engine control module
Describe the fuel lines.
Designed to deliver high and low pressure fuel in the fuel delivery system, fuel return systems, and the EVAP system.
What can fuel lines be made out of?
Plastic or metal and come in many shapes and sizes
What does EVAP stand for?
Evaporate emission control
Describe the fuel rail.
High pressure tubing which takes fuel to the injectors
Describe the fuel injector.
When signaled by the ECM the fuel injector opens and sprays pressurized fuel into the engine.
How long is a fuel injector open for?
The duration that the injector is open, is proportional to the amount of fuel delivered.
Describe the air filter.
Filters the air going into the engine
Describe the throttle body.
A throttle body is a butterfly valve, it regulates how much air can go into the engine, based on driver input through the gas pedal. As more air flows into the engine, it injects more fuel, thus allowing for more power.
Where is the throttle body located?
Located between the air filter and the intake manifold
How can the throttle position be controlled?
Controlled by a cable or through sensors and an electric motor
Describe the fuel return system.
Unused fuel is returned to the fuel tank and therefore runs in a continuous cycle. The fuel pump is always running in this type of system.
What system cools down the fuel and also prevents vapour lock?
A fuel return system
How is the pressure regulated in a fuel return system?
Regulated through the fuel pump and the pump will change speeds to maintain a constant pressure at the fuel rail.
What does EFI stand for?
Electronic fuel injection systems
What does TPS sensor stand for?
Throttle Position sensor
Describe the TPS sensor.
Monitors the throttle position of a vehicle
What does MAF sensor stand for?
Mass air flow sensor
Describe the MAF sensor.
Monitors the amount of air flowing into an engines intake system
What does CTS sensor stand for?
Coolant temperature sensor
Describe the CTS sensor.
Monitors the temperature of the engine coolant
What does IAT sensor stand for?
Intake air temperature sensor
Describe the IAT sensor.
Monitors the temperature of the air coming into the engine
What does CKP sensor stand for?
Crankshaft position sensor
Describe the CKP sensor.
Monitors the exact crankshaft position
What does CMP sensor stand for?
Camshaft position sensor
Describe the CMP sensor.
Monitors the exact location of the camshaft(s)
What does MAP sensor stand for?
Manifold absolute pressure sensor
Describe the MAP sensor.
Monitors intake manifold vacuum/pressure
What does AFR sensor stand for?
Air fuel ratio sensor
Describe the AFR sensor.
Monitors exhaust to determine actual air fuel ratio accurately
What does O2 sensor stand for?
Oxygen sensor
Describe the O2 sensor.
Monitors oxygen In the exhaust to determine the proper combustion and converter efficiency
What are the outputs (actuator) for the fuel injection system?
Fuel injectors, fuel pump, ignition coils or distributor.
Describe the ignition coils or distributor.
Determined when to supply spark to ignite the air fuel mixture
What is the relationship between input sensors and output actuators?
info about engine operation will be recorded by the input sensor, be processed and then adjusted by the output actuators.
What are the 8 alternative fuels available?
- hydrogen
- electric
- hybrid
- propane
- methanol
- biodiesel
- E85 Ethanol
- Natural gas
What is the biggest factor effecting our increased use of alternative fuels?
Is simply cost of production and distribution
A rich mixture would be considered a mixture with more ____ and less ____.
More fuel and less air
A lean mixture would be considered a mixture with more ____ and less ____.
More air and less fuel
When warming up a vehicle want kind of fuel air mixture is needed? Lean or richer?
Richer mixture
What are ratios for a rich mixture?
13:1, 10:1, 8:1
What are ratios for a lean mixture?
16:1, 18:1, 20:1
Gasoline is refined from the liquid component of ___________.
Crude oil
