Fuel injection is commonly used in car and truck engines to deliver the fuel to the combustion chambers. Around 20years’ ago, it was more common to find carburetors doing the same job, but since then carbs have gradually been replaced in all but the simplest engines (eg in a lawn mower tractor engine will often still use a carb).
The main difference between an engine that uses a carburetor versus fuel injection is that fuel injection system pumps the fuel through a small nozzle to atomize it at high pressure, so delivering a fine spray of fuel into the combustion chamber. In contrast, a carburetor relies on suction to draw the fuel into the chamber.
Fuel injection systems work with both gas and diesel fuel – and the injectors are designed specifically for the type of fuel being used.
There are several benefits to using a fuel injection system instead of a carb-based setup. These include smoother and more predictable engine response, easier starting, smoother engine idle and running, and increased fuel efficiency.
And lastly, a car with a fuel injection system does not have a choke, which on carburetor-equipped vehicles must be operated when starting the engine from cold and then adjusted by the driver as the engine warms up.
Check out the articles and guides at http://fuelinjectorcleaner.net for more information.