6 Main Fuel System Components (and Their Functions)

The fuel system is responsible for supplying fuel to the internal combustion engine. The fuel mixes together with air and then the spark plugs ignite the mixture to create the combustion power which moves the vehicle.

After you fill up your gas tank with fuel, there is a system in place which transfers that fuel to the engine when it is needed. The more demand you put on your engine, the more fuel that it needs to receive.

The car fuel system is comprised of several different components to make this entire process happen smoothly. There is a fuel pump, fuel tank, fuel lines, fuel filter, fuel injectors, and carburetor.

It is really no different than the heart, veins, and kidneys of your body working together to keep you moving. If just one of these components were to malfunction, it could interfere with the entire fuel transferring process. Then your engine would either not function at all, or it would function very slowly.

See Also: 140+ Parts of a Car (with Pictures)

Parts of a Fuel System in a Car

Below is a list of the components of a vehicle’s fuel system. When you perform routine maintenance checks on your vehicle, you’ll want to make sure these components are in satisfactory condition. If you notice wear and tear on any of these components, then you should replace them immediately to prevent problems with your vehicle.

1) Fuel Pump

bad fuel pump

Inside of the fuel tank, there is a component called a fuel pump. A lot of newer cars have the pump inside the tank. If you have an older vehicle, you might find the fuel pump positioned in the middle of the engine and fuel tank. It may also be connected right on the engine as well.

The job of the fuel pump is to pump fuel into the engine. You probably have an electric pump powered by the car battery if the pump is inside the fuel tank. Otherwise, the engine’s motion will power the pump if it is on the outside.

Related: 7 Symptoms of a Faulty Fuel Pump

2) Fuel Tank

water in gas tank symptoms

The fuel tank should be self-explanatory. When you pump fuel into your vehicle, the fuel is going into your fuel tank.

This is where your fuel is stored before it is pumped to the internal combustion chamber. You might also find the fuel pump and emissions technology inside of it as well.

See Also: 5 Symptoms of Water in Your Gas Tank

3) Fuel Filter

bad fuel filter

The engine must have clean fuel for it to function properly and keep running smoothly. The fuel filter is usually positioned around the fuel pump, either before or after it.

When the fuel gets pumped from the fuel tank, any tiny particles and contaminants in it are blocked by the filter before the fuel enters the engine. A clogged fuel filter will make your car undriveable so make sure you follow the manufacturer’s fuel filter replacement schedule.

4) Fuel Injectors

fuel injectors

The fuel injectors of modern vehicles are controlled by electric sensors and computers. Whenever you step on the gas or put more demand on the engine, a small electric valve is signaled to open and allow fuel to enter the internal combustion chamber.

When the demand is over with, the valve is signaled to close. This valve is basically the fuel injector of the vehicle.

Related: 7 Signs of a Bad Fuel Injector

5) Carburetor (older cars)

As you know, the internal combustion engine needs a mixture of air and fuel before the ignition takes place. On older cars which are not fuel-injected, a carburetor is the component which is responsible for mixing the fuel and air together.

After the mixture takes place, it is sent to the combustion chamber where the spark plug ignites it.

See Also: Carb Cleaner vs Brake Cleaner (What’s the Difference?)

6) Fuel Lines

fuel lines

There are all kinds of fuel lines in the fuel system. Fuel lines are how the fuel can travel from one component to another. They are how fuel travels from the fuel tank to the fuel injectors, for example.


4 thoughts on “6 Main Fuel System Components (and Their Functions)”

  1. I was looking to that part that is placed over the fuel injectors like a crown. It’s a kind of fuel line supplied by the injection pump other than the ones that is directly connected at the back of the injection pump. I don’t know its name.

    • Are you talking about the fuel rail? Do a quick search for your year, make and model, followed by “fuel rail” and see if that gets you what you need.


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