Lift pump (In tank)

April 27, 2020, 08:25:23 PM

The lift pump is a small fuel pump situated inside the fuel tank, and found in all petrol injection Mk2 Golfs. It is not found in carburetor and Diesel variants.

Item no. 5 on this diagram:

VW Part no. 357906092C. Unlike the main fuel pump the part is the same for all cars and injection systems.

Two part numbers are given for the strainer 191906098C and 191906098F but they are usually supplied with a new aftermarket pump.

It is attached to the fuel level sender unit (item 2 on the diagram above). It stands vertically and sucks fuel from the lowest point of the tank. There is a filter/gauze/strainer attachment for the pump inlet which prevents particles from the tank to enter the fuel system. Like any filter this can get clogged and lose it's efficiency, and in extreme circumstances could become detached from the pump. At time of writing even the youngest cars are 24 years old now, and any plastic part that has spent that long being submerged in petrol is likely to have become brittle and could crumble.

The purpose of the lift pump is quite simply as the name suggests, to lift the fuel from the fuel tank and act as a helper pump to feed the main external fuel pump.

The lift pump is situated inside the fuel tank and can be accessed via the black cover in the boot floor.

Once the cover is removed you'll see the top of the sender unit.

Depending on year, the plug to the sender unit will vary and has either 3 or 4 pins, but as the pump itself fits to this unit the same pump is used across all models.

Failure of the cheaper lift pump will cause extra strain on the more expensive main external fuel pump and it is very common for both pumps to fail within a short period. By the time the failure is detected and even once the lift pump is replaced, it may already be too late if the main pump has had to work harder for a period. At time of writing the lift pump can be acquired for around £20-30. The main pump for a Digifant around £60-80 but a K-jet around £160. For the sake of £30 it would be advisable to fit a precautionary lift pump from a reputable brand on any newly acquired injection Mk2 Golf as part of the initial new owner service.