EFI

 What is EFI? Simply 

 

EFI stands for Electronic Fuel Injection and
it is used in petrol and diesel engines as well.
Talking about petrol vehicles. In old vehicles,
gasoline and air are mixed and given to the engine in the right ratio by the carburetor.
In EFI, the simple process of the carburetor is done through a complex electronic system.
There are several parts of this system.

• 1 ECU
• 2 sensors
• 3 injectors
• 4 actuators
• 5 fuel pump.

If we are talking about the sensors, the sensors used may change depending on the model of the vehicle as the technology changes, let's
talk about the 10 available sensors that are usually found in the majority of efi vehicles.

01 Temperature sensors 

There are 2 types of this sensor,
Coolant Temperature sensor

The temperature of the engine coolant is measured by this sensor.
Intake Air Temperature Sensor

This measures the temperature of the air coming to the engine through the vehicle's air filter.

02. Manifold Absolute Pressure Sensor

There are two intake manifolds and exhaust manifolds. Among them, the sensor that monitors the pressure in the intake manifold is called the Manifold Absolute Pressure sensor.

3. Mass Airflow sensor

That sensor is there to know the air mass or Air Flow going from the filter to the engine. That means the air quantity is calculated as a mass..

4. Throttle Position Sensor

This sensor is there to monitor the throttle flapper position.

5. Oxygen sensor

The sensor that detects the percentage of oxygen in the air in the exhaust manifold.
New vehicles often have 2 of these. (before and after the catalytic converter)

6. Speed ​​sensor

This shows the speed of the vehicle.
This is often used for ABS and tire pressure. Vehicles with ABS have 4 sensors on 4 wheels.

7. Neutral Start Switch

The simple act of indicating that the gear of an auto vehicle is in neutral or parking is done by this sensor.

8. Exhaust Air Temperature Sensor.

This exhaust is the temperature sensor that has been installed to know the temperature of the exhaust gas. This is often after the catalytic converter.

9. Knock sensor

When an engine knocks, the vibration that comes is of a high frequency... The knock sensor does this by waiting to see if the high frequency is coming from the engine. According to the data of that sensor, the ignition timing of the engine is changed (advance or retard).

10. Crank shaft position sensor.

This shows the angle at which the crankshaft rotates.
In some vehicles, the signal from this sensor does not come, otherwise the petrol pump will not work.
There are other sensors, these 10 are the most used.

Sensors are used to get data from various systems of the vehicle. The sensors can be compared to the sensitive organs in our body (eyes, ears, nose, tongue, skin) and
the data obtained from those sensors is given to the ECU through wires.
These wires work as our body's superior nervous system that carries data from sensory organs to our brain

Then what is this ECU?

ECU is short for Engine Control Unit.
Also, this device is known as ECM (engine control model).
This ECU can be compared to the brain of our body (not as advanced as the brain).

What the ECU does is to analyze the data obtained from the sensors and identify the current state of the vehicle.

The most important thing happens next.
According to the data provided by the sensors, the ECU determines the condition of the vehicle, and the appropriate amount of petrol is given to the engine by the injectors.

Things like injectors and solenoids that work according to the information provided by the ECU are called actuators.
The actuators that work according to the signals of this ECU can be compared to the muscle system that works according to the signals received from our brain.

The amount of fuel injected from the injectors is controlled by increasing or decreasing the time that the solenoid valves of the injector are open from the signals given as electric pulses from the ECU.

Giving petrol to the engine from the injectors is done in two ways
1. Direct Injection
2. Indirect Injection.

The efficiency of EFI engines is relatively high because the vehicle's current ignition condition is accurately identified, the air-fuel ratio is determined very accurately, and the fuel is supplied.
Also, since a complete combustion process takes place, the damage to the environment is also less. 

Asitha  lakshan