2008 Fabia 1.4 tdi Greenline .

Normally fill up once a month on 520 ish miles . Starting to notice its gettuing harder to fully fill tank . Trigger on fuel pump is cutting out around the 35 ltr mark ( or lower ) regardless of mileage  . Tried pumping slower , pulling trigger out partly of tank , stopping / starting etc etc with little luck . Last fill up was well into the reserve ( 47 litre tank , reserve kicks in at 42 ltr used ,  iirc ) but stiil only squeezed 35 ltr in , giving a super 69mpg ( I wish , normally 55 - 59 mpg winter running ) . 

I'm assuming maybe the vent is blocked , just unsure how to sort it . Hoping the tank doesn't need to be dropped . 

Suppose I could live with it , but really want the range . Was mulling over running a very small flexi pipe directly into the tank on the next fill , see if this would vent it ? It'd be messy , but maybe worth a try . 

Anybody else had similar issue ?

Do you always fill up at the same pump? I do not see how the filler nozzle can restrict the venting of the tank. If you think you can feed a small bore pipe down the side of the nozzle, then you don't need to!

Thinking about it, yes I do normally use the same garage. Not sure if their triggers are overly sensitive. Reason I mentioned the pipe is I'm assuming the fuel tank has a built in vent pipe, that is maybe blocked. There is a very  small hole built into the filler compartment, just under where your hand would be, maybe that's the vent. 

The hole just in front of the filler, at the bottom, is a drain, not a vent.

There are other pipes coming up to that area, including one to the vent valve, which is opened/closed as the cap is screwed in, by the button-like thing on the right side, which you can accidentally or deliberately press when filling. It is supposed to be actuated by the cap being screwed in.

 

Hard to imagine how any -except the drain pipe - could get blocked. The vent valve could stick, I guess?

 

Look at diagrams of the tank on parts sites such as https://www.lllparts.co.uk/catalogs/ to see representations of the pipework.

Diesels won't have the carbon canister or associated pipe(s).

18 hours ago, Cheapas said:

Thinking about it, yes I do normally use the same garage. Not sure if their triggers are overly sensitive. Reason I mentioned the pipe is I'm assuming the fuel tank has a built in vent pipe, that is maybe blocked. There is a very  small hole built into the filler compartment, just under where your hand would be, maybe that's the vent. 

There is a vent pipe, for when the fuel filler cap is in place. There is no need for a vent pipe when you are filling up as there is plenty of space around the filler nozzle for air and fumes to escape. Try another garage, just once, to see if it makes a difference.

Fuel lacking in defoaming agent, I can't tell you what filling station to use as I've only bought fuel in the UK a handfull of times in 2 years but back then my Octavia one was terrible for blowing back when filling, I adopted several strategies but it was always a very slow process and if I wanted to properly brim the tank I would finish the job at home with a 5l can.

 

The first time I bought diesel in France I was shocked that it didn't happen until the very last of the fill, the fuel was not foaming like the (then) UK fuel.

 

Times have changed I bought diesel after that in the UK that definitely did have defoaming additive, maybe most fuel companies add it most of the time but from your recent experiences there are exceptions.