What determines the amount of fuel injected when an injector opens?

The amount of fuel supplied to the engine is determined by the amount of time the fuel injector stays open. This is called the pulse width, and it is controlled by the ECU. The injectors are mounted in the intake manifold so that they spray fuel directly at the intake valves.

How is the amount of fuel delivered by a unit injector controlled?

The amount of fuel injected is controlled by a flap valve located in the engine’s air intake. This alters the position of a shuttle valve within the metering control unit to allow more fuel to be squirted into the cylinders. From the metering unit, the fuel is delivered to each of the injectors in turn.

How does fuel injection system work?

A modern fuel injection system works by atomising the fuel at high pressure, mixing it with clean air as it passes the inlet manifold, before entering the combustion chamber of each cylinder. The key element of the electronic modern fuel injection system is the word “electronic.”

Do port fuel injectors inject fuel above the throttle plate?

The injectors are located in an injector pod above the throttle valves. The quantity of fuel the injector spray into the intake manifold is continuously controlled by the ECU. Most of the TBI systems use bottom fed fuel injectors.

What are unit injectors operated by?

A unit injector (UI) is a high pressure integrated direct fuel injection system for diesel engines, combining the injector nozzle and the injection pump in a single component. The plunger pump used is usually driven by a shared camshaft.

Where are injectors fitted?

intake manifold
Fuel injectors are located in the intake manifold and spray fuel through a tiny nozzle. The fuel injector uses a special nozzle to spray the fuel as mist, instead of a strong jet stream. Just think of the nozzle on the hose you use in your yard. You can change how the water flows out of your nozzle.

How many fuel injectors does a car have?

A car generally has one fuel injector per cylinder. So, if you drive a four-cylinder car, it will most likely have four fuel injectors.

How does the ECM control the fuel injection amount?

The ECU determines the amount of fuel to inject based on a number of sensor readings. Oxygen sensors tell the ECU whether the engine is running rich (too much fuel or too little oxygen) or running lean (too much oxygen or too little fuel) as compared to ideal conditions (known as stoichiometric).

How does a fuel injector work in an engine?

In order to provide the right amount of fuel; the engine control unit is equipped with a, whole lot of sensors. Fuel injectors deliver fuel to the combustion chamber directly or indirectly. During its evolution the fuel injector has moved, from the intake manifold to the combustion chamber.

What type of fuel injection system is used in cars?

A fuel injection system Petrol-engined cars use indirect fuel injection. A fuel pump sends the petrol to the engine bay, and it is then injected into the inlet manifold by an injector. There is either a separate injector for each cylinder or one or two injectors into the inlet manifold.

What is the difference between carburetor and mechanical fuel injectors?

Whereas carburetor systems deliver low pressure fuel from the gas tank, a mechanical fuel injector delivers high pressure fuel to an accumulator. You can think of this as a temporary storage area for your fuel. The fuel then passes through a distributor which is typically considered as the metering control unit of the system.

How do I know if my fuel injectors are bad?

Fuel injectors make a sharp clicking sound, when they are functioning properly. So, the absence of this sound can indicate, a problem with an injector. In general, fuel injectors are hard wearing and with a little care, can often last; the life of the engine. Like any other engine part, regular maintenance is the key, to keeping them going.