A fuel system or fuel injection system is a mechanical system that delivers the proper amount of fuel to the engine. The fuel system comprises the carburetor, fuel filters, fuel pump, fuel lines, and fuel tank. The fuel system should work properly for the proper operation of the vehicle. Therefore, you must clean the system properly. In the previous article, we discussed how to use fuel system cleaner. This article mainly explains the fuel system working, types, parts, and function.
What is a Fuel System?
A fuel system is a part of the car that takes fuel from the fuel tank and delivers it to the engine. This system is responsible for supplying fuel according to the engine requirements. Each part of the fuel system must work properly to achieve desired engine performance.
The main function of the fuel system is to take fuel from the storage tank and deliver it to the engine combustion chamber, where it mixes with air, vaporizes, burns, and generates mechanical power.
The fuel system consists of an injector, pump, filter, fuel tank, and carburetor. The proper working of all these parts is very important to achieve the desired performance of the vehicle.
A fuel storage tank uses to store the fuel, which can be either gas, diesel, or petrol. When the engine needs fuel, a fuel pump takes fuel from the fuel tank, passes through the fuel lines, and transfers it into the carburetor.
The carburetor takes air from the environment and makes an air-fuel mixture. As the air-fuel mixture is made, the fuel is delivered to the combustion chamber, where the combustion process takes place.
Working of Fuel System
Fuel injection system is the part of the vehicle that is responsible for the proper supply of fuel to the engine. A fuel system works in the following way:
- First of all, a fuel pump takes fuel from the fuel tank and passes this fuel through a fuel filter.
- This filter removes debris from the fuel. It prevents the fuel injector, fuel lines, and carburetor from clogging.
- As the fuel is filtered, the fuel is sent into the fuel injector through the fuel lines. The plastic material or durable metal is used for the construction of fuel lines. These lines are located under the car floor and appear to be in vulnerable places. They install in an area that can’t damage from engine exhaust, weather, road conditions, or other components.
- The working of the fuel injector varies according to the design of the engine. In the case of a diesel engine, the fuel injector directly injects fuel into the combustion chamber. However, in the case of a SI engine, the injector firstly injects fuel into the carburetor, which firstly makes an air-fuel mixture and then sends this mixture to the combustion chamber.
- A pressure regulator is used to control the pressure of the fuel injector fuel.
- As the fuel enters the carburetor, the carburetor takes air from the environment, mixes the air with fuel, and makes an air-fuel mixture. As the air-fuel mixture is made according to the engine requirements, it delivers to the combustion chamber.
- The combustion chamber compresses the air-fuel mixture, ignites the mixture, and generates mechanical power.
Watch the below given video for better understanding:
Read Also: Different types of Engines
Types of Fuel Systems
The fuel system has the following major types:
- Multi-Point System
- SPFI system
- Direct Injection system
1) Single-Point or Throttle-Body Injection
The single-point injection system is one of the most famous types of the fuel injection system. It is also known as the throttle body injection system.
In this system, the carburetor replaces with up to two fuel injectors in a throttle body. For the starter, the throttle body works as the starting point for the car’s engine ventilation system, much like the starting point for the intake manifold.
Before the advent of the multi-point injection system, throttle body injection systems were a good alternative to simple carburetors. These are not as precise as multi-point injection systems, but they deliver excellent efficiency compared to carburetors.
In addition, the single-point fuel injection system requires very low maintenance and repair. It has an easy design than the multi-point injection system. It has low maintenance and repair costs.
The main disadvantage of this system is that it is less efficient and less precise than the multi-point unit.
Advantages and Disadvantages of Single-Point Injection System
|It requires low maintenance and service.||it is less efficient than a multi-point injection system.|
|This system delivers more excellent efficiency than the carburetor system.||It is less precise than a multi-point unit.|
|It has an easy design.|
|It has low maintenance and repair costs.|
2) Multi-point Injection System
A multi-point fuel injection system is a most commonly used injection system. It provides a separate injector nozzle for each cylinder. This type of fuel injection system installs on outside of each air intake. Therefore, it is also known as a port injection system.
Bringing the fuel vapor close to the air intake draws the fuel vapor fully into the cylinder and improves the efficiency of the combustion process.
One of the main advantages of the multi-point injection system is that it regulates fuel more efficiently than single-point fuel injection or carburetor. In addition, this system reduces the chances of fuel shortening in the intake manifold. This system is more precise than the single-point injection system.
Advantages and Disadvantages of Single-Point Injection System
|It is more precise and efficient than a single-point injection system.||it requires more maintenance.|
|It reduces the chances of fuel shortening in the intake manifold.||It has more maintenance and repair costs than the single-point fuel injection system|
|It controls fuel more efficiently than single-point fuel injection or carburetor.||It has a complex design.|
3) Sequential Port Fuel Injection System (SPFI)
The SPFI system is also called a timed fuel injection system or sequential fuel injection system.
The main difference between a sequential injection system and a multi-point injection system is that in the case of multi-point fuel injection, all injectors inject fuel at the same time. This means when the engine is idling, fuel typically remains in an orifice for more than 148 milliseconds. It may not seem like a long time, but actually, this is enough time to reduce efficiency.
While in the case of the SPFI system, all injection nozzles don’t inject fuel simultaneously, and each nozzle injects fuel according to the corresponding cylinder requirements. These nozzles inject fuel just before the opening of the inlet valve. That means the fuel doesn’t have to stay long. Therefore, this system increases efficiency and reduces emissions rate.
One of the main advantages of a sequential injection system is that it is more precise than a multi-point injection system. It also increases engine efficiency.
Read Also: Types and working of IC Engines
4) Direct Injection System
This is one of the most simple and innovative type of injection system. This system injects fuel directly into the combustion chamber after opening the valves.
Direct fuel injection systems are most commonly used in diesel engines but have recently become popular in petrol engines as well.
For example, the Hyundai Venue’s 1.0-liter turbocharged petrol engine uses a direct-injection system sold as the “GDI.” In this configuration, fuel preparation and injection timing are superior than any other injection system.
Read Also: Working of Direct Injection system
Components of Fuel System
The fuel system has the following major parts:
- Fuel Tank
- Fuel Pump
- Fuel Injector
- Fuel Filter
- Fuel Lines
- Fuel Gauge
- Fuel Gauge Sending Unit
- Emission Vapor Controls
- Fuel Pressure Regulator
1) Fuel Tank
A fuel tank is a place where fuel (such as gas, diesel, or petrol) is stored. If the fuel tank is clogged or leaked, the fuel can’t be supplied properly to the combustion chamber of the engine. The proper operation of this tank plays a big role in the proper working of the vehicle. A fuel pump uses to deliver fuel from the fuel tank to the carburetor or combustion chamber.
2) Fuel Pump
A fuel pump takes fuel by the fuel tank and delivers it to the fuel injector through fuel lines. In the case of the petrol engine, the fuel injector injects fuel into the carburetor. In contrast, in the diesel engine, the fuel injector directly injects fuel to the combustion chamber.
The fuel pump has the following major two types:
- Mechanical fuel pump: An engine uses to drive this pump. A chain or belt uses to connect the motor to the fuel pump.
- Electric fuel pump: An electric fuel injection system uses to control this pump. It has more reliability than a mechanical pump. It has very low-reliability problems.
Read Also: Working and types of Fuel Pumps
3) Fuel Injector
A fuel injector uses to inject the fuel into the combustion chamber of each throttle body or each cylinder. Actually, a fuel injector is a nozzle with a valve that creates a spray of fuel and air droplets.
The fuel injector is powered by a fuel pump. It takes fuel by the fuel pump. The injection process of the fuel injector varies according to the nature of the engine.
In the case of a diesel engine, the fuel injector injects fuel directly into the combustion chamber. In contrast, in the petrol engine, the fuel injector firstly injects fuel into the carburetor where fuel is mixed with air, and then the carburetor transfers the air-fuel mixture to the combustion engine.
A carburetor is most commonly used in the petrol engine. The main function of this part of the fuel system is to make an air-fuel mixture.
As the fuel injector injects fuel into the carburetor, it sucks air from the environment, mixes it with the injected fuel, and makes a fuel-air mixture. After proper mixing, the carburetor transfers the fuel-air mixture to the engine combustion chamber for the combustion process.
Read Also: Working and types of Carburetor
5) Fuel Filter
The fuel filter plays a big role in the proper operation of the fuel supply system. Due to the tight tolerances of fuel injectors, they can be damaged very easily by debris, and fuel-injected vehicles also use electric fuel pumps.
The fuel filter installs in between the fuel pump and fuel tank. As the fuel tank sucks fuel from the fuel tank, the fuel firstly passes through the filters. The filters remove the fuel solid contamination and then deliver filtered fuel to the fuel pump.
6) Fuel Lines
The fuel lines link all the different parts of the fuel system. These lines supply fuel from the fuel tank to the fuel injector. Flexible hoses and steel lines transport the fuel from the tank to the engine.
Do not use copper or aluminum when repairing or replacing steel fuel lines. You must replace the steel lines with steel. Similarly, when you replace the flexible rubber hose, you must use the correct hose. When you are replacing, carefully disconnect all hoses from the exhaust system.
7) Fuel Gauge
You can see the fuel gauge on the dashboard of your car. It is connected to the fuel tank. It uses to show the driver an actual fuel quantity in the tank.
In traditional vehicles, the fuel gauge couldn’t show an exact amount of fuel in the fuel tank. If this is your first time driving a classic car, take the time to understand the precision of the system. This part of the fuel system eliminates the hassle of running to a gas station when your tank runs out of gas!
8) Fuel Gauge Sending Unit
In the case of a fuel system, it is probably your biggest concern. The sending unit is a flawed design at best. This unit is most precise between 1/4 and 3/4 of the gas in the tank. Even if the tank limit (full or empty) is reached, the display becomes less accurate.
9) Emission Vapor Controls
These controls use in combination with fuel return lines. This part of the overall system uses to prevent petrol vapors from being discharged into the ambient air. When this happens, following some bad things can happen:
- A bad odor of gasoline enters the car
- The earth-shattering roar of gasoline fumes ignites
- it’s bad for the environment
10) Fuel Pressure Regulator
This unit of the fuel delivery system makes sure that the system properly maintains a proper amount of pressure. The fuel pressure regulator unit is most commonly used in fuel-injected vehicles because fuel injectors generate more pressure than carburetors.
Symptoms of Bad Fuel System
A bad fuel system affects the performance of the engine. A bad fuel system has the following major signs:
- Difficult Engine Starting
- Engine stalling issues
- Irregular power loss
- Engine idling issues
- Extreme Engine Smoke
- Unpleasant fuel odors
- A reduction in fuel economy
Advantages and disadvantages of fuel injection system
Advantages of Fuel Injection System
- It increases the engine and vehicle performance.
- It prevents the engine from damage.
- The fuel injection system increases the engine service life.
- It increases engine efficiency.
- It offers better fuel efficiency.
Disadvantages of Fuel Injection System
- A fuel injection system has many parts, including a fuel tank, fuel pump, fuel lines, and fuel injector. Therefore, this system increases the weight of the vehicle.
- The parts of this system have a high cost.
- It has high repairing and maintenance costs.
What is a Fuel Injection System?
A fuel injection system is a vehicle part that delivers fuel from the fuel tank to the engine combustion chamber.
What is the function of Fuel system?
The main function of the fuel system is to store fuel in a fuel tank and deliver fuel to the combustion chamber of the engine, where it mixes with air, compresses, vaporizes, and burns to generate desired mechanical power.
What are types of Fuel Injection Systems?
The fuel injection system has the following major types:
- Throttle-body injection
- Sequential fuel injection system
- Multi-point injection system
- Direct injection system
What is a Dual Fuel System?
The dual-fuel system is a home comfort system that combines an electric heat pump and a furnace, alternating between two sources of fuel to maximize comfort and efficiency.
What are the Fuel system parts and function?
The fuel system has the following major parts and function:
- Fuel Tank: It uses to store the fuel.
- Fuel Pump: It uses to supply fuel from the tank to the fuel injector.
- Filters: The filters are used to remove the solid contamination from the fuel.
- Fuel Injector: The fuel injector uses to inject fuel into the combustion chamber.
- Pressure Regulator: It uses to handle and maintain the pressure inside the system.
- Fuel Gauge: It shows the amount of fuel in the fuel tank.
- Fuel Lines: These lines use to supply the fuel to the different parts of the fuel system.