Genuine Mercedes 2184700694 Fuel Pump, Electric; Left – Mercedes

The electric fuel pump on your Mercedes pumps fuel from the fuel tank to the engine and builds fuel pressure for your vehicle’s fuel injection system. The electric fuel pump can be located inline between the fuel tank and the engine or inside the fuel tank and may be fitted with a fuel filter and fuel level sensor for the fuel gauge.

Electric fuel pumps can fail in several ways. Furthermore, other failed components of your Mercedes’ fuel delivery system can mimic a failed fuel pump. Weak fuel pressure causing your engine to run lean can be due to a fuel pump not pumping adequate volume, a clogged fuel filter, or a leaking fuel pressure regulator. Additionally, a fuel pump not pumping any fuel and preventing the engine from running could be a completely failed fuel pump or a fuel pump relay not supplying power to the fuel pump to operate. Always checking power to the electric fuel pump and fuel pressure at the pump will help to prevent a misdiagnosis of a problematic fuel pump.

Signs of a Failing Electric Fuel Pump

• Vehicle not starting
• Idling rough
• Stalling
• Engine surging
• Severe lack of power

Additionally, a strong fuel smell inside your Mercedes may be a sign an in-tank electric fuel pump has a cracked housing and is leaking fuel vapor into your vehicle.

Replacing Your Mercedes’ Electric Fuel Pump
The electric fuel pump in your Mercedes should only be replaced if failed or damaged. For electric fuel pumps located in the fuel tank with the fuel level sensor, the fuel pump would be replaced as part of the fuel pump and level sensor assembly if the fuel tank level sensor needs to be replaced.

Replacement of the fuel pump can take anywhere from one hour to several hours to replace depending on location. Electric fuel pumps located in the fuel line are often heavily covered to prevent damage from road debris and some fuel pumps located in the fuel tank will require the removal of the fuel tank to remove and replace. To prevent premature failure of a newly installed fuel pump, it is highly recommended to replace the fuel filter or fuel pickup screen to prevent contaminants from entering the fuel system and damaging the fuel pump.

Mercedes Fuel Pumps.