How a Fuel Pump Works?

A fuel pump is used to supply fuel to the fuel injection system. A fuel injection system is more efficient than its predecessor the carburetor and can better operate at extreme temperatures while becoming more dependable at start up. A fuel injection system reacts better to situations such as high altitudes, extreme temperatures and variable fuel quality. Fuel is forced under pressure into the fuel injection system and then into an internal combustion engine. The fuel injection system is an integral part of a modern vehicle's engine fuel management system.

Simply put, the purpose of a fuel pump is to draw fuel from the fuel tank then to deliver it to a fuel injector. All vehicle engines operate by way of a mechanical pump or via a fuel injected pump. Chances are if your engine requires a mechanical pump it is quite old and has carbureted fuel pumping at a low pressure from a fuel tank to the carburetor. Nonetheless, most likely your engine uses a fuel injected pump as do most modern engines and transfers fuel at a high pressure into the fuel injection system from an electrical pump mounted outside the fuel tank.

Typical Fuel Injection System

Mechanical Pumps

Before the modern prevalent usage of electronic fuel injection pumps most carbureted vehicle engines used mechanical fuel pumps to move fuel from the fuel tank into the fuel sections of the carburetor. However, more recently, as vehicle engines shifted from carburetors to fuel injection, mechanical fuel pumps are increasingly being replaced with electric fuel pumps. This is because electronic fuel injection systems generally run more effectively at higher fuel pressures than mechanical pumps.

Fuel Injected Pumps

Fuel injection pumps are basically a fuel delivery apparatus that supplies fuel pressure into the fuel injection system. Fuel injection pumps are part of an electronic system which means that they are controlled by a computer system that oversees key factors including the air to fuel ratio, the contents of the exhaust gases and the actual position of the throttle. Fuel injection pumps, which are usually electric, are located within the fuel tank or near the gas tank in order to maintain a steady amount of fuel and to utilize the fuel in the tank to cool the pump.

When Fuel Pumps Fail

There are a couple of reasons why your fuel pump will fail, be it mechanical or electrical. Fuel pumps can experience wear and tear on the armature, brushes or bearings. In addition, roller gears and pump vanes can also wear down. This will cause a gradual loss of pressure and poor engine performance. Some causes of fuel pump failure can include rust or dirt because they can get past the inlet filter sock which is set up to block these sediments. When this occurs the fuel pump will break down because of contaminants that have infiltrated the pump and cause it to jam. This will result in having the motor overheat and burn out. Sometimes a fuel pump will not work properly if it is not given the proper amount of fuel needed to run adequately. Your vehicle’s fuel pump relies on fuel running through it to cool and lubricate it. Starving your fuel pump for fuel can cause your vehicle's fuel pump to fail prematurely.