Fuel Pump Function

The fuel pump ensures that there is always enough gasoline for combustion. It is located in or near the fuel tank and pumps the correct amount at the proper pressure through the fuel lines to the engine. The external fuel pump delivers proportionally more fuel, as more is needed when power increases. It also creates a cooling effect by being flushed with gasoline.

Mechanical and Electric Fuel Pumps

Older, low-power engines typically have a mechanical diaphragm fuel pump that transports fuel from the tank to the carburetor and is driven by the camshaft. However, these pumps are not suitable for higher-power engines as they do not meet the requirements for a constant fuel supply.

Newer fuel pumps are electronic and perfectly designed for newer fuel injection systems. These pumps deliver gasoline at appropriate pressure to the injectors, which inject it directly into the combustion chamber in the case of direct injection, or only into the intake manifold in the case of manifold injection. With direct injection, a high-pressure pump is usually still required to compress the fuel and direct it from there to the high-pressure injection valves. Electric fuel pumps are designed to deliver more fuel than necessary to maintain the required pressure at all times. The excess amount is returned to the tank. This prevents fuel from building up in the engine and causing overheating. You run into real problems when the pump doesn't deliver enough fuel.

What happens if your fuel pump fails?

Whether your engine is tuned or not, a broken fuel pump is a risk to it and your safety. The engine will no longer receive enough fuel, and you may experience misfires, loss of power, sputtering, or even stalling. Poor starting can also be due to a defective fuel pump. If you notice these symptoms, it's time for a new pump, as your car is now unpredictable and could break down at any time. Some of the most common causes of broken fuel pumps include defective contacts, relays, wires, seals, and fuses. Even with powerful engines, especially when cornering, there can be big problems if the pump does not provide the necessary power. That's why you need a high-performance pump when tuning.

Thirsty Engine - Why Upgrade the Fuel Pump?

When you start to increase your engine's power, for example through chip tuning, a new sports camshaft, an optimized intake tract, a more powerful turbocharger, or an upgrade of the injection valves, at some point upgrading the fuel pump or adding a second pump makes sense. In any case, you need to ensure that your engine gets more fuel faster for the extra power. This increased delivery is more important than pressure, as most (smaller) series pumps also have sufficient pressure. In this case, a modification of the standard pump is often sufficient.

What are the advantages of tuning the fuel pump?

Your modified engine usually needs more fuel than a standard engine. Without enough fuel, you risk not only a drop in performance due to fuel pressure drop but also significant engine damage.

High-Pressure and Low-Pressure Pumps.

Depending on the installed system, you need a low-pressure pump and/or a high-pressure pump. For a 2.5L TFSI, for example, you need the low-pressure pump located in the tank and the high-pressure pump on the engine, which is supplied by the low-pressure pump. For extreme power increases from 400 PS (294 kW) upwards, you need to upgrade both pump systems so that your engine doesn't run lean. We have complete kits in our online shop that control the pump based on pressure, so your racing pump always delivers the right amount of fuel.

Which pump is right for you?

Which pump is right for you depends on your car, the installed tuning parts, and your needs. That's why we are happy to advise you in finding the optimal fuel supply. Simply contact us.