Fuel Injection

On newer cars fuel injection has taken over the role of the carburetor. This is primarily due to the fact that the fuel injected engine is much more efficient and reliable than that of the carbureted engine. Fuel injection is much more reliable when it is cold outside and doesn’t have the problems like “flooding” that carburetion does. This is when fuel drips into the engine and “floods” the engine so it cannot be burned.

Fuel injection is a process that is controlled by the vehicles computer system. When you step on the gas the throttle body opens up its valve to allow more air into the engine. The ECU (Engine Control Unit, the computer that controls everything on the engine) senses that more air is being allowed into the engine so it pushes more fuel into the system. There are many different sensors that monitor this and make sure that the ratio of air and fuel being mixed is correct.

The fuel is “injected” into the engine by a number of injectors. These injectors are pulsating valves that are electrically controlled. When a current is run through them the valves magnetically open to allow the fuel to squirt into the engine. The longer the valve stays open the more fuel consumption there will be. The injector’s other job is to make sure that the fuel being put into the engine must be atomized, or made into as fine of a mist as possible. This makes for a cleaner burn and more efficient.

The fuel is brought to the engine by the fuel pump which was stated in a previous blog. The fuel is pressurized in a fuel rail that connects all of the injectors and supplies it with the fuel needed to burn.

The injectors have taken over the carburetion world just like computers have taken over most of the world’s industrial needs. These intricate computer systems along with fuel injection have allowed us to design and produce hybrids and very fuel-efficient vehicles. So the next time you get in your car and start it up, stop and think. There is a lot more going on under the hood than you might think!