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Why the gas pump does not pump gasoline

One of the most important elements in starting the vehicle is the electric fuel pump, which is located in the vehicle’s fuel tank. The fuel pump pumps fuel into the system by creating a certain pressure.

The main symptoms of fuel pump failure and malfunctions in its operation are:

  • the vehicle is difficult to start, the engine is unsteady, sags, jerks when pressing the accelerator pedal, etc. are observed;
  • the pump does not pump after turning on the ignition switch and the fuel pump does not pump, the engine does not start.

There are also cases when the fuel pump stops pumping directly while driving. The engine starts to malfunction in such a situation and shuts down immediately after the remaining gasoline in the fuel line is used up. The problem may occur regularly or periodically.

The gasoline pump does not pump: causes and diagnosis

If the gas tank is full, charged, the wires are dry and there is a spark to them, and the starter motor spins the engine normally – but the engine does not stall, then you should pay attention to the fuel pump. A common problem is that the fuel pump does not receive power after the ignition is turned on. A similar malfunction occurs when the fuel pump is turned off and the engine suddenly stops.

Equally important is how much the fuel pump is pumping. In other words, the pump may be humming and buzzing (powered) but not producing the required pressure in the fuel line. The pressure in the fuel system must be more than 3 bar for a working fuel pump (it depends on the model of the vehicle). This pressure accumulates in the fuel rail and has a value of 300 kPa and higher.

To check this, you need to measure the pressure in the fuel rail with a pressure gauge, taking into account the indicators that are the norm for a particular model of car.

Also noted in the general list of possible reasons for the fuel pump does not pump:

  • Failure of the fuse of the fuel pump;
  • Breakage of the fuel pump relay;
  • Problem with the mass of the fuel pump;
  • Malfunction of the electric motor of the fuel pump;
  • Oxidation or breakage of fuel pump contacts and terminals;
  • The pump itself is defective

Preventing failures of the fuel pump

To extend the life of the fuel pump, it is necessary:

  • Pay attention to the quality of fuel filled into the vehicle.
  • Absolutely exclude the possibility of water penetration into the tank.
  • During regular maintenance, pay attention to the change of fuel filters.
  • In case of mechanical damage to the fuel tank, disassemble the fuel pump and check its condition.
  • Regularly clean the fuel tank from possible deposits consisting of the smallest solid particles contained in the gasoline.

Compliance with these simple rules is beneficial not only for the fuel system but also for the engine itself.

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How do I drive a vehicle with a defective fuel pump?

Operating a vehicle with a defective fuel pump will soon cause the engine to burn out. Despite a defective fuel pump, you can take the vehicle to the nearest garage or to your home. If you follow these methods, you can hope for success.

  • Use of a fuel pressure gauge

This is a method that even professional mechanics use to troubleshoot the fuel pump. Thus, it is the most reliable method to start a car with a faulty fuel pump.

This method is quite simple and does not require exceptional engine maintenance skills. All you need to do is to connect the fuel pressure gauge to the car engine. This will allow your vehicle to start even if the fuel pump is defective.

  • Using external pressure

Vehicles with a faulty fuel pump cannot supply enough pressure to run the vehicle. So when the pressure drops, the power will drop or the car will stall, making the engine unable to start. To fix this problem, you can apply external pressure to your vehicle. The pressure source you choose will ensure that your engine gets the pressure it needs to start.

  • Keep Warm

When your car cools down, the fuel pump can relieve pressure without the need for heat and pressure. This is one of the reasons why cars start even with a faulty fuel pump. However, this causes various parts to malfunction and significantly reduces the performance of the vehicle.

Another way to solve the problem with the fuel pump is to control the heat in the car. You need to supply a moderate amount of heat to the engine. This will reduce the number of malfunctions and stabilize the performance as much as possible.

Thus, your car’s engine should neither cool down nor get too hot. A significant amount of heat will help you get your engine running and also prevent malfunctions.

It is not a permanent solution

Even if you manage to start your car with one of the above methods, it doesn’t mean that you can constantly try to start your engine with this method and not worry about fuel pump repair.

Conclusions

However, don’t take the above methods as an alternative to getting the problem professionally fixed. Make sure that your fuel system is serviced regularly. And if your car shows signs of a faulty fuel pump, act as soon as possible before it gets stuck in the doldrums.

How to Diagnose a Failed Car, Truck & SUV Fuel Pump - Video

FAQ

Can you run a car with a bad fuel pump?

If your fuel pump is bad enough, your car simply won’t start. Because of the important role they play, fuel pumps are meant to be tough and withstand almost the entire life of your car.

Why do fuel pump relays go bad?

Actually, much of the time, it is not the relay itself that goes bad. Rather, it is the solder joint(s) between the relay and circuit board that go bad. Because of this, a “bad” fuel pump relay can often be fixed by resoldering the relay to the board.

David Muench (Carnes Mechanical)

David Muench (Carnes Mechanical)

Hey, I’m David. I’ve worked in a cars store for 6 years. I write reviews and guides, helping people to choose the most suitable technicals and best product for them. I’m happy to finally share my knowledge of the industry here, on CarnesMechanical.

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