Fuel pump connections - 2011 A4 Avant - why one unused fuel connection on pump???

[cgfen]

I have raw fuel smell after recent fill up (at $6.37 a gallon, thank you california).
I took the plate off and saw a bit of fuel adjacent to the pipe at 10 o clock.
I know there are two electrical connections and one fuel as shown.

I'm surprised to see that pipe at 10:00 is not covered / connected and there are no other lines hiding out of view.

What is this unused pipe used for?

Maybe fuel pump failure mode is to allow gas out this pipe?

Fuel pump.jpg


Edit: A thread on B8 S4 forum says
– Press release tab and disconnect fuel line -2- at flange.
– Press release tab and disconnect fuel line -1- (if fitted) leading to metering pump for auxiliary heater at flange.

I guess I don't have -1.

Now I suspect that the cap or other connection is failing so I'll just replace the pump and see what happens



Thanks

[Smac770]

Fuel driven auxiliary coolant heater, PR 9M9, not offered in the US. Basically, it was a remote controlled diesel fired heater for the coolant so the cabin would be warmed up before going out to the car and starting the main engine.

The factory installed pumps were different for 9M0 (sealed second port) vs 9M9 (open second port). But long after production ends, the R&R stock is "fits all applications", so the second port is always open and you have to cap it. 8E0201263G for B8.0 (Bosch pump), 8R0201263A for B8.5 (VDO pump).

The pic isn't direct enough regarding the aux heater port to see if it's sealed or open.

[Theiceman]

that port should be sealed off or have a cap over it ..

- - - Updated - - -

Fuel driven auxiliary coolant heater, PR 9M9, not offered in the US. Basically, it was a remote controlled diesel fired heater for the coolant so the cabin would be warmed up before going out to the car and starting the main engine.

The factory installed pumps were different for 9M0 (sealed second port) vs 9M9 (open second port). But long after production ends, the R&R stock is "fits all applications", so the second port is always open and you have to cap it. 8E0201263G for B8.0 (Bosch pump), 8R0201263A for B8.5 (VDO pump).

The pic isn't direct enough regarding the aux heater port to see if it's sealed or open.

circa volkswagen 1968 lol

[cgfen]

Thanks for the replies.
I checked and the uncapped port is internally sealed.
Fuel pump R&R fun coming up.

[cgfen]

I bought and installed a replacement Bosch pump.
Note that it came with the unused port capped.

Pro Tip - when trying to fit it back into the tank, extend the pump and reservoir which enables insertion. Good luck inserting it if you don't extend the assembly.

fuel pump replacement (4).jpg