How to Start a Car with a Bad Fuel Pump (Explained)

How to Start a Car with a Bad Fuel Pump

A car’s fuel pump is an important fuel system component responsible for transporting fuel from the gas tank to the engine. When the pump fails, your car won’t run, leaving you stranded and frustrated.

However, there are some temporary solutions you can try to start a car with a bad fuel pump. Even though they are not long-term solutions, they can help you get your car to a mechanic for proper repair.

How to Start a Car with a Bad Fuel Pump

Here’s how to start a car with a bad fuel pump:

Check and Replace the Fuel Pump Relay

Sometimes, what seems like a fuel pump failure might be a faulty relay. The relay is an electrical switch that controls the power supply to the fuel pump. You can simply check the pump relay to be sure it is not your problem.

To check the fuel pump relay, you should:

  • Check your car’s manual to find the location of the fuel pump relay fuse. It is usually located in the fuse box, either under the hood or inside the car.
  • Remove the relay and inspect it for any signs of damage or corrosion.
  • Find a similar relay in the fuse box (like the horn or AC relay) and swap it with the fuel pump relay to see if it’s the relay problem.
  • Try starting the car. If the car starts, the problem is likely the relay. Replace the faulty relay with a new one.

However, while doing this, ensure you are swapping the relay with one that has the same specifications to avoid causing damage to other components.

Tap the Fuel Tank

Sometimes, the fuel pump motor can get stuck and refuse to work, a gentle tap will reset the problem.

Therefore, if the fuel pump motor is stuck, you might be able to temporarily fix it by tapping the gas tank with a rubber mallet or a piece of wood. This can sometimes jolt the fuel pump motor enough to get it working temporarily.

All you have to do is to identify the location of the fuel pump which is usually located inside the fuel tank and gently tap the bottom of the fuel tank with a rubber mallet or a piece of wood. Avoid using metal objects to prevent sparks.

After tapping the tank, try starting the car. This method can sometimes jolt the fuel pump into working temporarily. However, do not hit the tank too hard, as this could cause damage to the tank or pump.

Apply External Fuel Pressure

You can try to manually pressurize the fuel system using a can of starter fluid. Spray the fluid into the air intake while trying to start the engine. This might help the engine to run long enough to generate fuel pressure.

To do this, you need to open the hood and locate the air intake system. Remove the air filter and spray a small amount of starter fluid directly into the air intake.

Try starting the engine immediately after spraying. The starter fluid should help the engine run briefly. Moreover, make sure to use only a small amount of starter fluid to avoid flooding the engine.

Jump the Fuel Pump Directly

Another way to start a car with a bad fuel pump is by using a portable electric fuel pump. If you have access to the fuel pump wiring, you might be able to apply direct power to the fuel pump using a jumper wire from the battery.

All you have to do is to:

  • Purchase a Portable Fuel Pump: Buy a portable electric fuel pump from an auto parts store.
  • Connect the Pump: Attach the pump to the fuel lines of your car, ensuring a secure connection.
  • Power the Pump: Use an external power source to run the pump, such as connecting it to the car battery.
  • Start the Car: With the portable pump providing fuel pressure, try starting the car.

However, be very careful with this method, as improper handling can cause damage or create a fire hazard. I don’t recommend this method to start a car with a bad fuel pump.

Ensure the Fuel Filter is Not Clogged

Sometimes, the issue might be a clogged fuel filter rather than a faulty pump. So all you have to do is to:

  • Find the location of the fuel filter.
  • Check the filter for any signs of clogging or dirt.
  • If the filter is clogged, replace it with a new one.

With a new filter in place, attempt to start the car. Make sure to use the correct replacement filter specified for your vehicle.

Will a Car Start With a Bad Fuel Pump?

A car with a bad fuel pump may struggle to start or may not start at all, depending on the extent of the pump’s failure.

Since the fuel pump’s role is to deliver fuel from the tank to the engine at the correct pressure, when it fails, the engine may not receive enough fuel to start and run properly. So the car may not start or may find it difficult to start.

Symptoms of a Bad Fuel Pump

  • Difficulty Starting: The engine may crank but not start because it isn’t getting sufficient fuel.
  • Stalling: If the car does start, it might stall soon after because the fuel delivery is inconsistent.
  • Engine Misfires: The engine might misfire due to irregular fuel supply.
  • Loss of Power: The car might struggle to accelerate or maintain speed.
  • No Noise from the Pump: Modern electric fuel pumps make a faint humming sound when you turn the key to the “on” position. If you don’t hear this, it might indicate a problem.

Conclusion

Dealing with a bad fuel pump can be frustrating, but these methods can help you get your car running temporarily. Whether it’s tapping the fuel tank, using starter fluid, or directly powering the fuel pump, these techniques provide a way to get your vehicle to a mechanic for a permanent repair.

Remember, these are temporary fixes and not substitutes for proper maintenance. A faulty fuel pump should be replaced as soon as possible to avoid further damage to your car.

My name is Chidiebere Onwuachu. I’ve been driving for 18 years and I can comfortably say that I have experience and expertise in driving and car maintenance.Since experience is the best teacher, 18 years of driving is enough to have the experience needed to share my knowledge and I’m not hesitating to do that.