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What Is A Car’s Fuel System and How Often Should I Service It?

how often to service your fuel systemWithout fuel, your car’s “get up and go” would be gone. This isn’t just about running out of gas, though, you probably shouldn’t let that happen either. A car’s fuel system is vital to the combustible engine’s operation. For the engine to receive the right amount of air to fuel ratio, it needs the fuel to travel from the gas tank to the engine, but how does it get there? What happens if there’s a failure in the fuel system? Learn how the fuel system works to keep your vehicle moving and how to service it to ensure your vehicle always has access to the fuel it needs. 

How the Engine Receives Fuel

The main components in the fuel system include the fuel tank, fuel pump, fuel filter, and injectors.

When you pull into a fueling station to get gas, that’s just the very beginning of the fuel’s journey in the combustion process. With the use of the fuel system, your vehicle is able to produce the power to propel your vehicle. 

How fuel gets to the engine is a step 4 process:

  1. After you place the nozzle into the fuel filler inlet and fill up the tank, as you drive away, the fuel pump sends the gas to the engine via the fuel lines. 
  2. Fuel lines are made of a durable metal and special plastic materials located underneath the vehicle tucked away from exposure or risk of damage from the elements, road hazards, and exposure to heat. Before reaching the engine, the fuel has one more stop.
  3. To protect the engine from hazardous debris that could damage the engine, the fuel must be filtered through the fuel filter. Because the fuel filter’s job is to trap dirty fuel and debris, after about 60,000 miles, it may become clogged. A clogged fuel filter may be unable to prevent contaminants from entering the engine and could restrict the flow and pressure, wreaking all kinds of havoc. Note: Most modern vehicles do not have serviceable fuel filters, as they are part of the fuel pump. The whole set up requires replacement.
  4. Finally, once the fuel has traveled through the filter it reaches the engine and is ready to be injected into the combustion chamber by the way of the fuel injector.

What is the Fuel Injection System In a Car?

Depending on the age of your vehicle, to deliver fuel to the engine for the combustion process, your car is either equipped with a carburetor, mechanical fuel injection, direct fuel injection, or electronic fuel injection. 


Carburetors use pressure created by suction from the engine to attract air. Unfortunately, carburetors are flawed in that they are unable to adapt to fluctuating RPMs. Because the throttle is supposed to determine how much air and fuel is needed at one time based on vehicle’s speed, which could vary and change the ratio, carburetors struggle to utilize fuel efficiently and run well.

Mechanical Fuel Injection

At first mechanical fuel systems depended on a fuel pump that would pump high pulsations of fuel into the injector for each cylinder. The pressure of the fuel received at the injector would force the unit open and spray into the combustion chamber’s intake. The system required pistons driven by camshafts, to generate the spurt of fuel needed, however, very little adjustments could be made to create the ideal fuel to air ratio. As a result, the ratio was quite suited for the engine’s weight or performance. Later, fuel distributors were introduced to regulate flow more accurately based on the intake of air into the engine.

Direct Fuel Injection

Direct fuel injection was mainly used in diesel vehicles and is thought to be one of the most efficient ways to use fuel. Fuel is injected directly into the cylinder in the combustion chamber. In diesel direct injection, the fuel is able to burn at the right moment where and when it is needed. Because of its leaner fuel to air mixture and how the fuel is released into the chamber the fuel is able to burn more efficiently and increase fuel economy. 

Electronic Fuel Injection

Electronic fuel injection is what most vehicles utilize today. This modern technique is more advanced and is controlled by the vehicle’s internal computer to improve fuel efficiency and performance. Based on calculations provided by the Mass Air Flow sensor, detecting how much air enters the engine, the fuel pressure regulator in response allows a precise amount of fuel through the injectors at a time. This allows the vehicle’s internal computer to determine how much fuel is required to operate most efficiently.

What Is Included in a Car’s Fuel System Service?

 Your car depends heavily on fuel to keep it moving. That’s why it’s so important to maintain your car’s fuel system. If any of the fuel components fail, especially the fuel pump, your car will struggle to run or quit entirely. To prevent this from happening to you, don’t allow your vehicle’s fuel level drop past a quarter of a tank, replace the fuel filter, and have the system cleaned regularly. By replacing your fuel filter every 60,000 miles and having a fuel system cleaning every 30,000 miles, you’re greatly reducing the likelihood of being stuck on the side of the road with faulty fuel injectors, a dirty fuel filter, or a failed fuel pump. 

Contact Sun Auto Service today to schedule your 4-Step Fuel System Cleaning which includes:

  • Engine De-Carbon
  • Fuel Injection Service
  • Throttle Body Service
  • Fuel Additive