How To Start a Car With a Bad Fuel Pump? (Complete GUIDE)

How To Start a Car With a Bad Fuel Pump – Have you ever found yourself in a situation where your car refuses to start, and a bad fuel pump might be the culprit? It’s undoubtedly a frustrating scenario, but fear not!

There are a few tricks and methods that might help you get your vehicle up and running temporarily.

A malfunctioning fuel pump can throw a wrench into your plans, leaving you stranded and scratching your head. But before you dive into panic mode or call for a tow truck, let’s explore some handy techniques to potentially breathe life back into your car’s engine.

Faced with a bad fuel pump, starting your car might seem like an impossible task. The fuel pump plays a critical role in delivering fuel from the tank to the engine. If it fails to function correctly, your car might refuse to start or, if it does, struggle to maintain operation due to inadequate fuel supply.

So, how do you start a car with a bad fuel pump?

In this comprehensive guide, we’ll explore various methods, signs of a failing fuel pump, and safety precautions associated with attempting to start a car with a bad fuel pump.

The Function of a Fuel Pump

The fuel pump in your vehicle is responsible for transferring fuel from the tank to the engine.

how to start a car with a bad fuel pump

There are two primary types of fuel pumps: mechanical and electrical.

Mechanical fuel pumps use a low-pressure system, while electrical fuel pumps utilize a positive electrical current to move fuel.

Both types contribute to maintaining the crucial air-to-fuel ratio necessary for combustion in internal combustion engines. Any deviation in the fuel pump’s function can disrupt this ratio, affecting the engine’s performance or causing it to fail altogether.

How To Start a Car With a Failing Fuel Pump

how to start a car with a bad fuel pump

Applying Manual External Pressure

One viable method to start a car with a failing fuel pump involves applying manual external pressure.

This approach involves using an external pressure source, such as an air pump connected to the gas tank, to manually replicate the pressure required for starting the car.

Other Methods to Consider

## Maintaining Consistent Engine Temperature: Allowing the engine to cool down might help reset the fuel pump without applying external pressure.

## Attaching a Fuel Pressure Gauge: Diagnosing the fuel pump’s condition by attaching a fuel pressure gauge to the engine can aid in determining if the pump is indeed malfunctioning.

Signs of a Failing Fuel Pump

Recognizing signs of a failing fuel pump is crucial for prompt identification and resolution of the issue.

Common symptoms include:

how to start a car with a bad fuel pump

  • Loud Whining Noise: An unusually loud whining noise emanating from the fuel tank.
  • Hard Start: Difficulty starting the engine, particularly with repeated cranking.
  • Loss of Power: Decreased power output during acceleration or uphill driving.
  • Poor Fuel Economy: Noticeable reduction in gas mileage.
  • Stalling in Warm Temperatures: Engine stalling or sputtering, especially in high temperatures.

Can You Start a Car With a Bad Fuel Pump?

Starting a car with a bad fuel pump is highly discouraged due to safety risks and potential damage to the engine.

Attempting DIY fixes or hacks found online, such as using carburetor cleaners or makeshift fuel pumps, poses significant risks, including fire hazards and engine damage.

Waiting for the engine to cool off before attempting to start the car might provide a temporary solution, but driving with a faulty fuel pump is risky and can lead to engine damage or fire.

how to start a car with a bad fuel pump

Diagnosing a Bad Fuel Pump

Using a pressure gauge to confirm low fuel pressure or employing an OBD-II scanner to retrieve error codes related to the fuel pump malfunction are practical methods for diagnosing a bad fuel pump.

How do you temporarily fix a bad fuel pump?

When dealing with a faulty fuel pump, a temporary fix involves bypassing the fuel pump relay. Locate the fuel pump relay in the vehicle’s relay box and replace it with the same type. This action bypasses the fuel pump’s electrical circuit, allowing the pump to operate despite its malfunction.

Will a bad fuel pump still crank?

In the case of a complete fuel pump failure where it cannot provide sufficient fuel for the engine to run, the vehicle will still crank when the key is turned. However, due to the lack of fuel supply, the engine will be unable to start.

Does tapping the fuel pump work?

A common yet inconsistent method for addressing a non-functioning fuel pump involves hitting the bottom of the fuel tank. This action aims to jar the pump motor, potentially encouraging it to work. While occasionally effective, it may not consistently resolve the issue.

How do you test a dead fuel pump?

For testing a non-functioning fuel pump in modern vehicles, a test port located on the fuel rail is often available. By turning the ignition to the “on” position (key on, engine off) and noting the gauge reading, a comparison with the repair manual’s specifications is necessary.

Significant deviations from the specified reading may indicate a bad fuel pump.

What does a clicking fuel pump mean?

Clicking noises during fueling signify fuel backing up in the fill tube due to excessive pressure from the gas pump. This rapid pressure is too high for the car to accept, causing the clicking sound as air flows through the tube while filling the tank.


Starting a car with a bad fuel pump might seem challenging, but it’s essential to prioritize safety and seek professional assistance.

Driving a car with a faulty fuel pump can pose significant risks to both the vehicle and its occupants.

Identifying signs of a failing fuel pump and employing safe diagnostic measures are crucial steps toward resolving the problem and ensuring your vehicle’s optimal performance and safety.

These methods might offer a glimmer of hope in starting a car with a bad fuel pump, but it’s crucial to emphasize caution and safety.

Attempting DIY fixes carries risks, and driving with a malfunctioning fuel pump can lead to severe engine damage or safety hazards.

In essence, these methods provide temporary solutions to a tricky problem. Seeking professional assistance for a proper diagnosis and permanent repair should be the ultimate goal to ensure your vehicle operates safely and reliably.

In the realm of automotive challenges, dealing with a bad fuel pump is undoubtedly one hurdle. However, armed with temporary fixes and an understanding of how to manage this issue, you can navigate through this obstacle and get your vehicle running temporarily, ensuring your safety and peace of mind.

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