1 Internal part of the housing for fuel intake
2 Connecting flange
3 Mounting clips
4 Mounting bolt
5 Wire
6 Wire clamp
7 Fuel hose
The fuel pump is installed on the underside of the fuel tank. The relay energizes the pump. An installed safety switch ensures that the pump only supplies fuel when the engine is running.
Fuel pump check
If the pump is not working properly, or if fuel is suspected to be insufficient, some steps can be taken to check the operation of the pump. It also requires some experience with electrical equipment. It is assumed that the corresponding fuse is OK. It's fuse number 17 in the fuse box.
To check the main pump activation, you need to raise the rear of the car, prop it on stands and listen next to the fuel tank to see if the fuel pump clicks when the assistant turns on the ignition. If this happens, then determine where the fuel remains.
Place a rag under the threaded connection of the fuel lines and loosen the connection. If fuel is spurted out, this is a sign that the fuel system is under pressure. If not, then turn on the starter. Fuel should now splatter. If this does not happen:
Remove the floor lining in the trunk and unscrew the black cover. Remove the multi-pin plug and check with a test lamp or voltmeter whether there is voltage between the two pins, i.e. those to which the brown and yellow/green wires are connected. To do this, turn on the starter. The described test shows that voltage is supplied to the pump. If there is no voltage. It can be assumed that the pump needs to be replaced.
Before replacing the pump, the pump relay must be checked.
Fuel pump replacement
The fuel pump is specially reinforced and requires a special key to remove it (3307). If this key is available, then the pump is removed together with the inside of the fuel intake housing.
Attention. The fuel tank can be no more than ⅔ full when the pump needs to be removed.
Open the boot floor trim and remove the black metal cover (arrows).
Remove the multi-pin plug and fuel return line, as well as the fuel supply line from the pump.
Now unscrew the connecting flange of the fuel tank. Usually a special key is used for this (2).
The plastic union nut has small ribs that can be used with a screwdriver (best stupid). With a light blow on the screwdriver, you can unscrew the nut.
Now pull up the connecting flange.
Remove the fuel return pipe from the inside of the flange. Loosen the clamp and pull the fuel line down.
Remove the fuel tank sensor plug.
The above special tool (1) now insert through the hole in the tank and insert into the inside of the housing to take fuel (2). Now turn the inside of the housing about 15°to the left, almost as far as it will go, to free the pump.
The pump with the inner part can now be lifted outward together with the connecting flange. Before removing the pump, be sure to remember or mark the installation position of the pump, the method of connecting hoses and wires, so that you can then install them in the same position. After marking and disconnecting the fuel supply line, the pump can be removed from the inside of the fuel intake housing. This operation depends on the diameter of the pump.
If the pump (1) has a diameter of 6mm, rotate the grid at the bottom of the inner case (3) to take fuel to the left and pull out the pump. When installing, you need to push the ledge (2) groove on the side of the pump. Don't forget the gasket.
If the pump has a diameter of 4mm, then compress the retaining clip on the top side of the inside of the fuel intake housing and pull out the pump. The pump can only be installed in one position.
1 fuel pump
2 Connecting flange
3 Fuel hose
The pump is installed in the reverse order of removal. Pay attention to the relative position of the pump and the connecting flange, as well as the correct position of the sensor wire in the fuel tank.
On vehicles with 2-wheel drive, install the connecting flange as shown on the right side of the figure and connect the hose in the manner shown. The electrical wire for the fuel tank sensor must be routed between the fuel return line and the fuel tank.
Vehicles with 4 wheel drive (Quattro) The connecting flange must be positioned as shown on the left side of the figure. The fuel tank sensor wire runs between the pump and the fuel tank.
Install the pump. Relevant labels (arrows) must align with the large arrow on the outside (3).
Secure the inside with the special key mentioned above.
When installing the connecting flange, pay attention to the installation position. Marked on the flange "QUATTRO" And "FRONT". "FRONT" in this case denotes 2-wheel drive models. Both options have an arrow that must match the arrow on the outside. Moisten the sealing ring of the connecting flange with petrol before installation.
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