How To Know If You Have A Subaru Fuel Pump Issue

The fuel pump is a vital component of your Subaru's fuel system, responsible for delivering fuel from the tank to the engine. However, over time, the fuel pump can develop issues that affect its performance and ultimately lead to engine problems. In this guide, we'll show you how to identify a Subaru fuel pump issue, including symptoms to watch for and steps for diagnosis and repair.

Symptoms of a Subaru Fuel Pump Issue

There are several symptoms that can indicate a Subaru fuel pump issue, including:

• Engine misfires or hesitation: A failing fuel pump can cause the engine to misfire or hesitate during acceleration.
• Difficulty starting the engine: If the fuel pump is failing, it may struggle to supply enough fuel to start the engine, leading to difficulty starting.
• Sudden engine stalling: A failing fuel pump can cause the engine to stall suddenly, particularly during acceleration or at high speeds.
• Whining or buzzing noise: A failing fuel pump may produce a whining or buzzing noise from the fuel tank area.
• Decreased fuel efficiency: A failing fuel pump can cause decreased fuel efficiency due to a lack of proper fuel delivery.

Diagnosis and Repair

If you suspect a Subaru fuel pump issue, there are several steps you can take to diagnose and repair the problem.

Step 1: Check the Fuel Pump Relay

The fuel pump relay is an essential component of the fuel system that controls the fuel pump's operation. If the relay is faulty, it can cause the fuel pump to stop working altogether. To check the relay, follow these steps:

• Locate the fuel pump relay in the fuse box.
• Remove the relay and inspect it for signs of damage or corrosion.
• Use a multimeter to check the relay's resistance and continuity.
• If the relay is faulty, replace it with a new one.

Step 2: Check Fuel Pressure

If the fuel pump relay is functioning correctly, the next step is to check the fuel pressure. Low fuel pressure can indicate a failing fuel pump or a clogged fuel filter. To check the fuel pressure, follow these steps:

• Locate the fuel pressure test port on the fuel rail.
• Attach a fuel pressure gauge to the test port.
• Turn on the ignition to prime the fuel system.
• Start the engine and observe the fuel pressure reading on the gauge.
• If the fuel pressure is lower than the manufacturer's specifications, the fuel pump may be failing.

Step 3: Replace the Fuel Pump

If the fuel pump is found to be the issue, it will need to be replaced. To replace the fuel pump, follow these steps:

• Drain the fuel tank of any remaining fuel.
• Remove the fuel tank from the vehicle.
• Disconnect the fuel lines and wiring harness from the fuel pump.
• Remove the old fuel pump and install the new one.
• Reconnect the fuel lines and wiring harness to the new fuel pump.
• Reinstall the fuel tank and refill it with fuel.

Preventative Maintenance

To prevent fuel pump issues from occurring in the first place, it's essential to practice proper preventative maintenance. Here are some tips:

• Regularly replace the fuel filter: A clogged fuel filter can cause the fuel pump to work harder, leading to premature failure.
• Avoid running on low fuel: Running on low fuel can cause the fuel pump to work harder than necessary and can also introduce debris into the system.
• Use high-quality fuel: Using low-quality fuel can introduce impurities into the fuel system, which can cause damage to the fuel pump over time.