A fuel pump is an important part of the fuel injection system of the car. It is responsible for supplying pressure to the fuel injectors. This is electrically controlled by the car’s ecu using a fuel pump relay. A fuel pressure regulator is used to control the pressure. This is normally located inside the pump or externally on the fuel rail.
Most fuel injection system primary fuel pumps are located inside the fuel tank. They have the fuel level sensor connected to the pump housing. Even though this electric motor is submerged in fuel there is no danger of fire due to the lack of oxygen inside the tank. Servicing the pump or level sender requires the removal of the pump which can be done through a service port in the car’s body or by removing the fuel tank. In the VAG cars this service port is under the rear bench seat.
SO WHY USE AN UPRATED FUEL PUMP?
Cars need a precise mix of oxygen and fuel to burn effectively. Much of the engine tuning done by ADE Tuning involves increasing the cars capacity to burn the air and fuel mix. This must be supplied in an exact ratio. If the pump is too weak the engine will lose fuel pressure at high revs. Fitting additional pumps or larger pumps will help to ensure a good delivery of fuel at the engine. Some cars experience starvation on long bends where the fuel pick up is on one side of the tank. If the tank is running low the fuel will flow to the other side of the tank causing the pickup to run dry.
There are many different brands of pumps and they can vary quite a bit in price. Always speak to your engine tuner as to what pump they would recommend. After all it is them who will be remapping your car.