Subaru Fuel System Service: Maximizing Mileage and Performance

The fuel system is an essential part of your Subaru, as blockages or problems in the system can cause various issues ranging from rough starting to failing to start at all. In addition, components like sensors can fail and cause engine damage. As your Los Angeles Subaru dealer, we want to tell you more about how we perform a fuel system service and the signs that one is necessary.

 

How Fuel Delivery Works

Fuel is securely stored in the fuel tank. When your engine is running, the fuel is pumped by the fuel pump through the fuel lines to the fuel injectors. On the way, it passes through the fuel filter, which traps dirt or other contaminants, preventing them from reaching the engine.

Once the fuel reaches the fuel injectors, sensors determine the precise amount of fuel that must be squirted into the intake manifold. Inside the manifold, the fuel mixes with air in a precise 14:1 ratio monitored by other sensors. Once the two elements have thoroughly mixed, the mixture is drawn into the cylinders. Inside a cylinder, the mixture is compressed and then ignited by the spark plugs at a precise moment to produce combustion. 

Cleaning the Fuel System

As time passes, the fuel filter can become blocked by contaminants, restricting fuel delivery and reducing engine performance and acceleration. Carbon and other substances can build up in the system and block the fuel lines or the injectors. Let’s look at the steps our Subaru-trained technicians take to fix all these issues.

Clean Injectors

As we saw above, the injectors spray fuel into the intake manifold in precise amounts. We carefully clean all the injectors to remove any fuel residue or build-up and clear any blockages in the injectors.

Clean the Throttle Body

Fuel varnish can accumulate and jam the fuel throttle. This varnish is the gummy residue of decaying fuel. Many drivers don’t know this, but fuel degrades if it’s left in the gas tank. Once the throttle has been cleaned, it will control the airflow into the manifold again.

Clean the Valves

This step is just as important as cleaning the throttle body, as the valves control fuel access into the injectors. Once they’ve been cleaned, the correct amount of fuel will pass through to the injectors.

Change the Fuel Filter

As we saw above, the fuel filter can become clogged. This restricts fuel delivery and can lead to engine trouble. After the filter has been changed, we add a fuel additive to your fuel tank. This additive continues to circulate through the fuel system and helps keep it clean.

Contact us today at Puente Hills Subaru in City of Industry, CA. We can help you get your fuel system running smoothly again.

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