Akin automobile engineering

27/10/2019

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09/11/2018

27/09/2017

What Do Oxygen
Sensors Do?
When a gasoline-powered engine
burns gasoline there is oxygen
present. Oxygen in an engine is the
result of a number of factors
including the air temperature,
altitude, engine temperature, load on
the engine, and barometric pressure.
The ideal ratio for oxygen and
gasoline is 14.7:1, which slightly
varies depending on different types
of gas. In the instance that there is
less oxygen present fuel will remain
after combustion, which is referred
to as a rich mixture. On the other
hand, if there is more oxygen
present it is referred to as a lean
mixture. Both the rich and lean
mixtures are bad for your car, as
well as for the environment. A rich
mixture results in fuel that is not
burned that creates pollution. A lean
mixture generates nitrogen-oxide
pollutants, which can lead to
decreased vehicle performance and
engine damage. Oxygen sensors are
positioned near points in the
exhaust system so to determine if
there are rich or lean mixtures in
your car. Typically, an O2 sensor
creates a voltage due to a chemical
reaction resulting from an off-
balanced gasoline to oxygen ratio.
Most car engines can determine
how much fuel to expend into the
engine based on the voltage of the
O2 sensor. If your oxygen sensor
fails to function properly, your
engine management computer
cannot determine the air to fuel
ratio. Therefore, the engine is forced
to guess how much gasoline to use,
resulting in a polluted engine and a
poorly functioning vehicle.
How to Test an
Oxygen Sensor
To test your oxygen sensor, you can
either leave it attached to your
vehicle or take it off for testing.
Testing requires two tools: a high-
impedance digital voltmeter and a
backprobe. A mechanic at a
Meineke repair shop has these
necessary and specialized tools for
checking O2 sensors. The first step
to checking an O2 sensor is to
locate the surrounding wires to
make sure they are intact and
without visible signs of wear and
tear. Next, the vehicle must be
started and allowed to run

13/08/2017

Electric Fuel Pump
Copyright AA1Car
An electric fuel pump is used on engines with fuel injection to pump fuel from the gas tank to the injectors. The pump must deliver the fuel under high pressure (typically 30 to 85 psi depending on the application) so the injectors can spray the fuel into the engine. Fuel pressure must be within specifications for the engine to run correctly. Too little pressure can starve the engine for fuel, causing it to run lean, misfire, hesitate or stall. Too much fuel pressure can cause the engine to run rough, waste fuel and pollute.
Electric fuel pumps are usually mounted inside the fuel tank, though some may be mounted outside the tank. Some vehicles may even have two fuel pumps (a transfer pump inside the tank, and a main fuel pump outside). The in-tank location helps muffle the buzzing noise produced by the electric pump motor, and immersing the pump in fuel helps lubricate and cool the pump motor. Driving with the fuel tank less than 1/4 full can shorten pump life by causing it to run hot. It also increases the risk of momentarily starving the pump for fuel when cornering sharply, braking or accelerating. Running out of gas can sometimes damage an electric fuel pump by starving it for cooling and lubrication.
The pump is usually part of the sending unit assembly, that includes a float that sends an electrical signal to the fuel gauge on the instrument panel. If an electric fuel pump needs to be replaced, it can be replaced as a separate item or as a complete module assembly (which is more expensive but easier and less troublesome).
Electric fuel pumps come in a variety of designs. Some older applications use a positive displacement "roller cell" pump. This type uses rollers mounted on an offset disc that rotates inside a steel ring. Fuel is drawn into the spaces (cells) between the rollers and pushed along from the pump inlet to the outlet. Roller cell pumps typically spin about 3,000 rpm. This type of pump can generate very high pres

13/08/2017

The fuel pump is an integral element of any car or truck. Given the responsibility of literally pumping a vehicle's fuel from its tank to the engine, a malfunctioning fuel pump will usually lead to total disaster. Car owners should be aware of common symptoms of a malfunctioning pump so they can take a preventative measure before the worst happens.

This guide is designed to explain the five most common signs of a failing fuel pump. That process begins with an explanation of the role and function of the fuel pump, which will help vehicle owners to understand the reasons behind a malfunction. Next, we'll detail common symptoms, everything from engine misfires to cars that won't start. By the end of this guide, car and truck owners will understand what symptoms to look for in their own vehicles.

All About Fuel Pumps

The fuel pump is an essential component of any vehicle with an internal combustion engine, principally, cars, SUVs, and trucks or even a hybrid diesel. A malfunctioning fuel pump delivers too much or too little fuel from the gas tank. While you're scratching your head looking at a full fuel gauge, an engine starved of gas will leave you stranded in the garage or on the side of the road. Motorcycles and some other vehicles don't require a fuel pump, relying on gravity to feed gas to the engine. Other internal combustion engines use either a mechanical or electric fuel pump.

The Mechanical Fuel Pump

The granddad of the industry is the mechanical pump. A mechanical fuel pump most always resembles a diaphragm. It uses the pumping action of that diaphragm shape to create low pressure of between 10 and 15 per square inch (psi) and transport fuel from the gas tank to thecarburetor. This action resembles that of a piston.

Mechanical fuel pumps are located on a mount outside of the fuel tank itself and, in general, are less likely to malfunction than electronic fuel pumps. The most common malfunction of mechanical fuel pumps occurs when the diaphragm inside

19/02/2017

Intake air temperature sensor can cause the ECU to either add too little or too much fuel to the engine's fuel and air mixture. This can cause engine misfires, increased emissions, poorer fuel economy, rough idling and surging. An entirely broken intake air

11/11/2016

Typical inductive crankshaft position sensor
A crank sensor is an electronic device used in an internal combustion engine to monitor the position or rotational speed of the crankshaft . This information is used by engine management systems to control the fuel injection or the ignition system timing and other engine parameters. Before electronic crank sensors were available, the distributor would have to be manually adjusted to a
timing mark on the engine.
The crank sensor can be used in combination with a similar camshaft position sensor to monitor the relationship between the pistons and
valves in the engine, which is particularly important in engines with
variable valve timing. This method is also used to "synchronise" a four stroke engine upon starting, allowing the management system to know when to inject the fuel. It is also commonly used as the primary source for the measurement of engine speed in
revolutions per minute .
Common mounting locations include the main crank pulley , the flywheel, the
camshaft or on the crankshaft itself. This sensor is the most important sensor in modern day engines. When it fails, there is a chance the engine will not start, or cut out while running. [citation needed ]
Types of sensor
Commonly a hall effect sensor is used, which is placed adjacent to a spinning steel disk. Other detection principles can be employed such as an optical sensor or
inductive sensor.
Some engines, such as GM's Premium V family , use crank position sensors which read a reluctor ring integral to the
harmonic balancer . This is a much more accurate method of determining the position of the crankshaft, and allows the computer to determine within a few degrees the exact position of the crankshaft (and thereby all connected components) at any given time.
Function
The functional objective for the crankshaft position sensor is to determine the position and/or rotational speed ( RPM ) of the crank. Engine Control Units use the information transmitted by the sensor to control parameters such as ignition timing and fuel injection timing. The sensor output can also be related to other sensor data including the cam position to derive the current combustion cycle, this is very important for the starting of a four stroke engine.
Sometimes, the sensor may become burnt or worn out. The most likely causes of crankshaft position sensor failure are exposure to extreme heat. Many modern crankshaft sensors are closed units and therefore will not be damaged by water or other fluids. When it goes bad, it stops transmitting the signal which contains the vital data for the ignition and other parts in the system.
A bad crank position sensor can worsen the way the engine idles , the pistons fire, or the acceleration behavior. If the engine is revved up with a bad or faulty sensor, it may cause misfiring, motor vibration or backfires. Accelerating might be hesitant, and abnormal shaking during engine idle might occur. In the worst case the car may not start.
The first sign of crankshaft sensor failure, usually, is the refusal of the engine to start when hot but will start again once the engine has cooled.

26/07/2016

Engine coolant temperature sensor(ECT)like humans, a vehicle needs to maintain a specific temperature in order to function properly. Too cold, and the vehicle will drink too much petrol.Too hot and the head gasket could leak. coolant is a liquid use in the vehicles radiator of the car to maintain the temperature at which the engine can perform at its optimum.The engine coolant temperature sensor simply tells the car's computer (ECM) the current temperature of the vehicle.when the temperature of the coolant reaches between 75 ans 95 degrees (depending in the manufacturer specificcation), the ECM instructs the radiator fan to turn on and start cooling down the liquid.

13/07/2016

Automobile engineering is a branch of s
engineering which deals with designing, manufacturing and operating automobile.it is a segment of vehicle engineering which deals with motorcycle, buses, truck, etc.it includes mechanical, electrical, electronic,software and safety elements.