Fuel pump Mercedes W210

The electric fuel pump is powered by a relay in the electrical box located in the engine compartment. The pump is only activated when the vehicle is running or the ignition is on to ensure the engine starts.

If you suspect a defect in this item, limit yourself to the following steps to find it.

1. Switch off the ignition.
2. Disconnect the pressure hose from the fuel distributor; be careful and have a container or rag ready for the fuel leak.
3. The fuel system is under pressure even after the engine has stopped.
4. If there is no gas, try turning on the ignition (never try to start the engine, that is, turn on the starter!).
5. If gasoline does not appear in this case, then you should check the relay or fuel pump fuse.
6. If the fuse is defective, replace it. If the fuel pump is now working, then the fault is in the fuse.
7. If the pump still does not work after replacing the fuse, check the voltage supply to the pump using a diode tester (a simple test lamp can destroy the control device). If you are not well versed in auto electrics, it is better to seek help from a specialist or a workshop.
8. If there is voltage, then in this case the problem may be with the pump or with a break in the connecting wires.
9. If the pump is running and no fuel is flowing to the manifold, the fuel filter or fuel lines are dirty.
10. If, after all the above checks, serviceability is not found, it remains to disassemble the pump and check it in detail.

Replacing the fuel pump Mercedes W210

1. Disconnect the gearbox ground from the battery.
2. Place the rear of the car on jack stands.
3. Remove the insert from the fuel pump-filter block.
4. Place a collection container on the ground under the fuel pump.
5. Lay rags around the pipes.
6. Clean the work area around the pump unit.

Before removing the pump, mark the electrical connections indicated by the arrows. 1. Suction pipe. 2. Holder. 3. Fuel pump. 4. Hollow screw pressure pipe.

1. Install clamps on both pump hoses and disconnect lines.
2. Loosen the clamps on the suction line and disconnect the hose. Don't forget to prepare your rags.
3. Unscrew the hollow screw on the discharge side of the pump and remove it together with the hose.
4. Disconnect the electrical cable from the pump.
5. Turn away a bolt of an arm and remove the fuel pump.
6. When installing the pressure line, use new O-rings and new clamps.
7. Connect the battery and turn the ignition on and off several times until the fuel pressure in the system is normal.
8. After all the steps, be sure to check the fuel lines for leaks.