What is fuel injection?
Fuel injection is a means of adding fuel to the incoming air of an engine.
Previously, fuel was added to the incoming air inside a carburetor. Air passing through the venturis of the carburetor would siphon fuel from the fuel bowl of the carburetor so that the fuel would mix with the air inside of the intake manifold. This air and fuel mixing inside the intake manifold is what is called a "wet" intake.
Fuel injection sprays fuel on the back side of the intake valves, just before the air enters the combustion chambers. The fuel mixes with the air inside the cylinders instead of the intake manifold. This is what we call a "dry" intake.
There are two basic types of fuel injection: mechanical and electronic.
Mechanical fuel injection was tried by General Motors back in the 1950s and 1960s on some of their Corvette engines. You can still find mechanical fuel injection systems being used by drag racers at the race track.
Electronic fuel injection has been in use on every vehicle for over 30 years, now. Solenoids, which we use as fuel injectors, are used to control fuel flow to the cylinders. The fuel injectors are, in turn, controlled by a computer. A variety of electronic inputs are fed to the computer to control when to open the fuel injectors and for how long.
Fuel injection, especially electronic fuel injection, was the necessary evolution of fuel control as a result of the U.S. Government's issuance of CAFE standards (Corporate Average Fuel Economy) dating back to 1975.
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