What is "fuel injection"

Injection \In*jec"tion\, n. [L. injectio : cf. F. injection.]

1. The act of injecting or throwing in; -- applied particularly to the forcible insertion of a liquid or gas, by means of a syringe, pump, etc.

2. That which is injected; especially, a liquid inserted thrown into a cavity of the body by a syringe or pipe; a clyster; an enema.
   --Mayne.

3. (Anat.)

   1. The act or process of filling vessels, cavities, or tissues with a fluid or other substance.

   2. A specimen prepared by injection.

4. (Steam Eng.)

   1. The act of throwing cold water into a condenser to produce a vacuum.

   2. The cold water thrown into a condenser.

      Injection cock, or Injection valve (Steam Eng.), the cock or valve through which cold water is admitted into a condenser.

      Injection condenser. See under Condenser.

      Injection pipe, the pipe through which cold water is through into the condenser of a steam engine.

      fuel injection, a method of inserting fuel into internal-combustion engines by directly forcing the liquid fuel into the combustion chamber at an appropriate point in the piston cycle; in contrast to carburetion, in which an air-fuel mixture is drawn in by the downward stroke of the piston.

n. the delivery, under pressure, of a metered amount of fuel, as a fine spray, into the intake airflow or combustion chambers of an internal combustion engine

n. mechanical system to inject atomized fuel directly into the cylinders of an internal-combustion engine; avoids the need for a carburetor [syn: fuel injection system]

Fuel injection is the introduction of fuel in an internal combustion engine, most commonly automotive engines, by the means of an injector.

All diesel engines use fuel injection by design. Petrol engines can use gasoline direct injection, where the fuel is directly delivered into the combustion chamber, or indirect injection where the fuel is mixed with air before the intake stroke.

On petrol engines, fuel injection replaced carburators from the 1980s onward. The primary difference between carburetors and fuel injection is that fuel injection atomizes the fuel through a small nozzle under high pressure, while a carburetor relies on suction created by intake air accelerated through a Venturi tube to draw the fuel into the airstream.