Mechanical or Electrical Fuel Pump in My Car?

September 11, 2017

The first step to recognizing whether your vehicle has a mechanical or electrical fuel pump is knowing the difference between the two. Regardless of which category they fall into, fuel pumps are used to move fuel from the tank and feed it into the combustion part of the engine; every car has one, and they are absolutely crucial to the running of the vehicle.


A mechanical fuel pump is more likely to be found on old vehicles, while new vehicles, which have more power and so need high-pressure fuel input, generally use electrical fuel pumps. For electrical fuel pumps, a computer system is used to regulate the flow rate and how high the pressure is, ensuring the engine is provided with precisely the right amount of fuel.

There are a number of differences between mechanical and electrical fuel pumps. Mechanical fuel pumps tend to be mounted on the side of the engine, and work by drawing fuel out from the bottom of the tank using a suction process. A diaphragm creates the suction, and a valve prevents the fuel from flowing back into the tank once the pump has filled up. The collected fuel is then released to the car Burnett or through a second valve. This process is continually repeated as the vehicle moves, and an arm is used to drive the pump, increasing as the revs per minute are increased. This means that there is enough fuel going into the engine even at higher speeds when there is a demand for more.


Electrical in-tank fuel pumps work in a different way. They are generally accessible from the top of the fuel tank, sometimes through the trunk floor or a hole under one of the seats. The pump will normally be mounted on a bracket in a case, which sits inside the fuel tank. These pumps don’t rely on the mechanical systems for drawing fuel, and are instead designed to be permanently immersed in fuel. As soon as electricity is sent to the pump, the motor kicks in and begins to propel the fuel up the lines to the engine. The electronics can determine the rate at which fuel is needed, and increase or decrease pump speed accordingly.

The biggest difference between the two pumps is that mechanical ones usually depend on moving parts to pull fuel out of the tank and into the engine, whereas electrical ones use electricity and computer power to push fuel to the engine. Mechanical pumps are usually designed to operate in dry conditions, and will not be damaged by running without fuel. Because of the higher pressure under which pushing pumps must work, electrical ones need to be immersed in fuel full time to ensure they are kept cool and lubricated. Completely running out of fuel in a car with an electrical pump may cause damage. Identifying some of the key differences between the two can help you establish which your vehicle is likely to have, and how it operates to keep your car running smoothly.

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