vacum in fuel tank a4

[nothctap]

Can any of you guys help a friend has got a 97 a4 1.8t sport
But it seems like the the engine running is causing a vacum in the fuel tank
So much so that it is sucking air through the cap.
Any ideas???y

[Flat on my back]

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Thinks there all spossed to do that...sounds more like the fuel cap has failed...try and borrow one to see.

[nothctap]

We've tried another fuel cap and it still does it, any more suggestions. Can anyone else confirm if it's normal?

[Flat on my back]

.

Excess fuel not required should be returned to the tank, might be a blocked/damaged return line or dodgy FPR...not too hot on the 1.8T's...sorry.

[Pirvu Eugen]

the valve from the carbon canister is blocked and there is no ventilation.
i have managed to implode my steel tank in my coupe because off that.
Hope this helps.

[Pirvu Eugen]

the valve i tell you is inside the tank at a4..i think.

[nothctap]

Thanks very much for your help, I'll let my friend know so that he can get it looked at!

[nothctap]

I've had a look on the ETKA and can't figure out which valve it is. Do you happen to know a part number for this valve so I can reference it against the ETKA?

Thanks

[Pirvu Eugen]

What year?
In the picture..is the possition 34 or 28....you have to finda valve between the tank and the line till the carbon canister.
Hope this helps!