Fuel Pump Replacement: When Is The Right Time?

Fuel pumps are built to last a long time—often over 200,000 kilometres or miles—but they will occasionally need to be replaced. The fuel pump is a crucial part of the fuel system, delivering fuel from the tank to the engine, so a failing pump can have a huge effect on your car. Here are some signs that your fuel pump needs to be replaced.

Warning signs of a failing fuel pump

The fuel pump is responsible for delivering fuel from the gas tank to the engine. It is usually an electrical component located inside the fuel tank, but some fuel pumps are inline or mechanically operated. A failing fuel pump can have a huge effect on your car, so it's important to be aware of the warning signs and ask a mechanic to inspect and replace the pump before it fails completely. Here are some warning signs to look out for:

Engine stuttering or surging

One of the most noticeable signs of a failing fuel pump is engine jolts and stutters while driving at a steady speed. This occurs when the pump struggles to deliver an adequate amount of fuel to the engine, causing the engine to have difficulty maintaining a certain speed. The opposite can also happen, with sudden surges of speed if the fuel pump supplies too much fuel. Both scenarios can be extremely dangerous as they affect the control you have over your vehicle.

Reduced fuel efficiency

An improperly functioning fuel pump can impact your vehicle's overall fuel efficiency. Inadequate or excessive amounts of fuel being fed to the engine will cause it to operate below peak efficiency, resulting in increased fuel consumption.

High-pitched noises

A high-pitched whine or squealing noise coming from the engine while driving could indicate excessive wear to components within the fuel pump. These noises often precede a more serious mechanical failure, so it's important to have an expert assess your vehicle as soon as possible.

Engine won't start

A damaged fuel pump may cause issues with starting your engine. If the fuel pump cannot deliver enough fuel to the engine, you may need to crank the engine excessively before it starts. In some cases, the engine may not start at all, leaving you stranded.

Check engine light

A faulty fuel pump may deliver too much or too little fuel to the engine, affecting the air/fuel ratio. This can cause the "check engine" light to illuminate on your dashboard, indicating a potential problem.

Overheating

A failing fuel pump may overheat due to inefficiency, which can then lead to engine overheating. A vehicle with this type of failure may operate for 15-30 minutes before stopping. After allowing it to cool down, the engine may run again, only to repeat the failure as it heats up.

How to diagnose a fuel pump problem

Diagnosing a fuel pump problem can be difficult, but there are some tell-tale signs to look out for. Firstly, you need to determine whether your vehicle has a mechanical or electric fuel pump. If your vehicle has a carbureted engine, it likely has a mechanical fuel pump. Most vehicles made after 1990 (and some made after 1986) have electric fuel pumps located inside the fuel tank, as they use electronic fuel injection.

If you have a mechanical fuel pump, it is unlikely to have failed. This is because mechanical pumps tend to fail entirely, so if there is a problem, your engine won't be getting any fuel at all.

If you have an electric fuel pump, there are several signs that it may be faulty:

• Whining noises: A common sign of a failing fuel pump is a loud whining or squealing noise coming from the fuel tank. This can be caused by a damaged pump or contaminated fuel.
• Engine stuttering: If your engine is stuttering or jolting while you drive at a steady speed, this could be a sign that your fuel pump is struggling to provide enough fuel to your engine.
• Sudden surges in engine power: If your engine suddenly surges in power, this could be because a faulty fuel pump is starving the engine of fuel and then delivering too much.
• Check engine light: If the check engine light comes on, it could be because a faulty fuel pump is delivering too much or too little fuel to the engine, affecting its air/fuel ratio.
• Car not starting: If your car won't start, it could be because the fuel pump has failed and is no longer able to deliver fuel to the engine.
• Reduced fuel efficiency: If your vehicle's fuel efficiency decreases suddenly, it could be because a faulty fuel pump is delivering inadequate or excessive amounts of fuel to the engine.
• Engine overheating: A failing fuel pump may overheat and cause the engine to overheat.

If you suspect your fuel pump is faulty, it is important to have it inspected by a qualified mechanic as soon as possible.

When to replace a fuel pump

Fuel pumps are generally built to last and can run for over 200,000 miles without needing to be replaced. However, there are some warning signs that your fuel pump is malfunctioning and may need to be replaced.

One of the most prominent signs of a faulty fuel pump is engine stuttering or jolting while driving at a steady speed. This occurs when the pump struggles to provide enough fuel to the engine, causing it to have difficulty maintaining a certain speed. This issue can be extremely dangerous as it affects your control over the vehicle. In some cases, a faulty fuel pump can cause sudden surges of speed by supplying too much fuel to the engine. This can also lead to the engine flooding and stalling.

Another indication of a failing fuel pump is a high-pitched whine or squealing noise coming from the engine while driving. This noise is typically caused by excessive wear to the components within the fuel pump and often precedes a more serious mechanical failure.

You may also notice a decrease in fuel efficiency if your fuel pump is not functioning properly. Inadequate or excessive amounts of fuel being fed to the engine can cause it to burn more fuel than necessary, resulting in a sudden decrease in mileage.

Additionally, if your engine is struggling to start or is not starting at all, it could be due to a faulty fuel pump that is unable to deliver enough fuel.

If you experience any of these issues, it is important to have your vehicle inspected by a qualified mechanic as soon as possible. Driving with a faulty fuel pump can create premature wear and tear on your engine and lead to safety hazards such as sudden engine power loss.

How to replace a fuel pump

When to Replace a Fuel Pump

Fuel pumps are integral to the operation of your vehicle, and any damage or malfunction can significantly impact its performance. It is important to identify the warning signs of a failing fuel pump to address the issue before it causes more serious problems. Here are some common symptoms of a defective fuel pump:

• Engine stuttering or sudden surges of speed while driving at a steady speed.
• Reduced fuel efficiency, resulting in increased fuel consumption and decreased mileage.
• High-pitched noises, such as whining or squealing, coming from the engine or the fuel tank area.
• Difficulty starting the engine, requiring excessive cranking before ignition.
• Sudden loss of power while driving, causing the engine to stall.

Preparing for the Replacement Process

Before attempting to replace the fuel pump, it is crucial to gather all the necessary tools and equipment, including a new fuel pump, fuel filter, and any other vehicle-specific components. Reducing the amount of fuel in the tank is advisable to minimise spillage and make the tank lighter and easier to handle. Working in a well-ventilated area, preferably outdoors, is essential due to the flammability and toxicity of fuel vapours. Always wear safety gear, such as safety glasses and gloves, to protect yourself from fuel spills and splashes.

Step-by-Step Guide to Replacing a Fuel Pump

The following is a comprehensive guide on how to replace a fuel pump in your vehicle:

• Park your vehicle on a firm, level surface and engage the parking brake.
• Locate the fuel pump, which is usually inside the fuel tank. Open the fuel cap and turn the key to the "ON" position. Listen for a brief hum, indicating that the fuel pump is functioning properly.
• Find and verify the fuel pump fuse and relay. If the fuse is blown, replace it with one of the same amperage.
• If the fuse and relay are functional, check for power and ground at the fuel pump. This may require removing the fuel tank or the rear seat for access.
• Relieve the fuel system pressure. There are two ways to do this:

• Method 1: Run the engine and pull the fuel pump relay while the engine is on, causing it to stall.
• Method 2: With the engine off, press the Schrader valve on the pressure line momentarily to release a small fuel spray.

• Siphon or drain as much fuel as possible from the fuel tank to reduce the risk of spills.
• Disconnect the filler tube hose and the electrical connection to the pump.
• Support the fuel tank with a jack and a block of wood. Remove any retaining straps or bolts holding the tank to the vehicle's frame. Carefully lower the tank.
• Locate the fuel pump within the tank and disconnect the fuel lines. Remove the old fuel pump.
• Compare the new fuel pump with the original to ensure you have the correct part.
• Install the new fuel pump and connect the fuel lines. Secure the fuel pump in place.
• Lift the fuel tank back into position and reinstall the retaining strap. Reconnect the filler tube hose and the electrical connector.
• Reconnect the negative battery cable and fill the tank with fuel.
• Conduct a road test to ensure that the new fuel pump is functioning correctly and that all connections are secure.

Tips for a Successful Fuel Pump Replacement:

• Work in a well-ventilated area to minimise the risk of fire and inhalation of harmful fumes.
• Always wear proper safety gear, including safety glasses and gloves, to protect yourself from fuel spills.
• Drain the fuel tank as much as possible to reduce the risk of spills and make the tank lighter.
• Clean around the fuel pump to prevent dirt and debris from falling into the fuel tank during the replacement process.
• Consider replacing related components, such as the fuel filter, fuel pump strainer, and fuel tank O-ring or gasket, for optimal performance.

Fuel pump replacement cost

The make and model of the vehicle, the number of labor hours needed, and whether other parts related to the fuel assembly need to be replaced can also influence the final cost. For instance, newer models from automakers like BMW, Honda, Chevrolet, and Toyota have an average cost for fuel pump replacement between $611 and $894.

It is important to note that the fuel pump replacement process is moderately complicated and may involve removing the fuel tank if no access panel exists in the passenger compartment. Therefore, it is recommended to have the pump replaced by a professional mechanic at a dealership's service department or a repair shop.

Additionally, related repairs may also be needed, and taxes and fees will further increase the total cost of the fuel pump replacement.

Frequently asked questions