How does diesel injector work

The ECM after receiving information from various control sensors determines the length of time the injectors need to be grounded to inject the exact amount of fuel given the horsepower output demand from the engine. The process of diesel injectors opening, closing and dispensing the correct amount of fuel happens in milliseconds.

Injector cycle firing is on average completed in 1. Diesel fuel injectors come in different shapes and sizes depending on the engine make and model as well as power demand. Automotive injectors are quite a bit smaller than heavy-duty diesel applications and are measured in cubic inches.

There are two types of diesel fuel injectors: the first is called throttle body injection where injectors are located in the throttle body itself in the diesel engine and supply a metered amount of mist fuel spray into the intake manifold.

This delivery system essentially charges the intake and the intake valve draws the fuel into the cylinder of the engine. The second delivery system, known as individual port type fuel injector, is newer and more fuel efficient. Port type of injection is more efficient than a carburetor since it adjusts to air density and altitude and is not reliant on the manifold vacuum. With throttle spray injection inefficiency comes when the cylinders closest to the injectors having a better mixture than the ones furthest away.

With port type of injection this flaw is eliminated by injecting the same amount of fuel to each cylinder in the engine. Each fuel injector is a little different but they all have 15 main parts including the filter, guide ring, core spring, seat spring, seat, pole piece, stop, solenoid coil, solenoid body, core ring, core, spray tip housing, director and spray tip.

These chips regulate fuel spraying, air intake, engine coolant, RPM, and other functions within the process. These types of engines do not include a glow plug. The computers chips work with an elaborate number of sensors to measure ambient air temperature and delay engine timing in cold weather. This process allows the injector to dispense fuel when the weather is warmer, for more efficient compression. Engine cylinders also have unique supply lines from the fuel tank for passing diesel into the injector.

Each cylinder features a filter that removes any impurities before the injection process starts. An integral part of diesel fuel injectors is the solenoid, which opens to pass the vaporized fuel. The process is called pulse width , and each cylinder receives a different fuel amount as calculated by the ECU.

The ECU also ensures the combustion process reaches an appropriate stoichiometric ratio, which is the proportion between air and fuel at which combustion begins. Part of this ecosystem is a small pump that forces air into the injector. The air ends up mingling with diesel, so the pump should be able to withstand increased amounts of pressure and high temperatures. A small nozzle is used to spray diesel into the combustion chamber. The nozzle features a sequence of holes to ensure even distribution within the cylinder.

The second valve sucks air from the combustion chamber and mixes it with vaporized diesel to further intensify the combustion process.

The exhaust valve then channels out emissions from the combustion chamber. The remaining fuel flows through the return fuel line to the tank. Do you have any questions about diesel fuel injectors or other diesel-related questions? One big difference between a diesel engine and a gas engine is in the injection process.

Most car engines use a combination of port injection, which injects fuel just before the intake stroke outside the cylinder , and direct fuel injection. Port injection is used at lower engine speeds because it has a more stable mixture of air and fuel.

Direct injection is used at higher speeds to provide more power and less chance of knocking, which is when the air is compressed too much and the fuel spontaneously ignites. Diesel engines only use direct fuel injection — the diesel fuel is injected directly into the cylinder. The injector on a diesel engine is its most complex component and has been the subject of a great deal of experimentation — in any particular engine, it may be located in a variety of places. The injector has to be able to withstand the temperature and pressure inside the cylinder and still deliver the fuel in a fine mist.

Getting the mist circulated in the cylinder so that it is evenly distributed is also a problem, so some diesel engines employ special induction valves, pre-combustion chambers or other devices to swirl the air in the combustion chamber or otherwise improve the ignition and combustion process.

Some diesel engines contain a glow plug. When a diesel engine is cold, the compression process may not raise the air to a high enough temperature to ignite the fuel.