There are two types of fuel pumps: mechanical and electric. Before fuel injectors became popular, most engines used mechanical fuel pumps. However, a common problem among these pumps is that fuel vaporized in the supply line because of the low pressure between the fuel and the pump, which caused cars to stall. These issues led to the development of electric fuel pumps which work more efficiently at higher fuel pressures.
The electric fuel pump is usually located inside the fuel tank. The pump pushes the fuel into the engine by creating a positive pressure in the fuel lines. It is safe to submerge the electric pump in the fuel tank because liquid fuel does not explode when ignited. The pump delivers a steady flow of fuel into the engine, and unused fuel returns to the tank. The fuel is not kept close to the engine so the risk of boiling is reduced.
When the car is turned on, the electric fuel pump starts working. The carburetors or fuel injectors measure the amount of fuel that the pump transfers into the engine. Today, many engines use a mechanism that allows the pressure to be controlled by the modulation of the pump voltage. This new technology reduces fuel consumption and makes the fuel pump last longer.
New automobile technology has allowed many improvements to be made on electric fuel pump design. In case of a car accident, some cars have the ability to shut down their fuel pumps even when the ignition is on. This prevents fuel leakage if some fuel lines are damaged. Other models can shut down their fuel pumps if they roll over or in case of a collision. Electric fuel pumps can also eliminate vapor locks if they are installed properly. Vapor locks happen when excessive heat turns liquid fuel into gas.
Electric fuel pumps are safer and more efficient today because of new technology. With these improvements, pump failures that are common among cars today should be reduced in the future.