ALT-1 How Fuel Injection Works
In order to meet the strict emissions and fuel efficienty laws, car manufacturers were faced with a huge problem. They realized that a carburetor was only capable of doing so much, and that with the current setup they would be unable to meet future government regulations. In order to meet this need, the fuel injector was created and the last car to use the carburetor was the Suburu Justy in 1990. Fuel injection itself has been around since the 1950's however, and didn't really start to gain a foothold until the 1980's when it began common practice in Europe to use fuel injections. Now all cars in the United States are equipped with fuel injectors.
Essentially a fuel injector is a basic eletronically controlled valve. The valve receives pressured fuel from the fuel pump of your vehicle, which causes the valve to open and close, often sveeral times per second. The fuel injector creates an atomized mist that allows for easy burning of fuel. This is caused by energizing an electromagnet which causes a plunger to open and close, shooting fuel through a tiny hole.
The ECU controls the fuel injectors. The amount of fuel supplied is dependent upon how long the nozzle stays open. This is referred to as the pulse width. This of course depends upon a variety of variables, including speed, gear, etc. This is all calculated by the ECU.
Fuel is supplied to the fuel injectors via the fuel rail. This fuel is pressurized.
The fuel injectors are directly mounted to the intake manifold so that they spray fuel directly to the intake valves.
That is basically how fuel injection works. There is a lot more to the overall process, including engine sensors and such, but that's a different topic altogether.
