Fuel tank help

[richking]

Hi, Ive tried to do a search but not really helped.

Im putting a 1.8t engine into a carb mk2 and ive fitted a mk3 fuel tank for the injection pump.

I have the fuel feed and return pipes with the tank but there is a third black pipe with a cut end.

The pipe starts at a white valve on the filler neck (I believe its called a gravity valve?) and runs down to the top of the tank

My question is what should this pipe connect to?

Thanks in advance

[Wayne]

I think that is just a breather hose from memory.

[benvictors]

Normally runs to the carbon canister for fuel vapours, the carbon canister then regulates the fuel vapours and pushes them into the inlet when the engine is warm and above idle speed.
Pretty sure you can vent to atmosphere but do it in a safe place (away from heat/ignition sources) and put a non return valve inline too 

[itavaltalainen]

why'd you vent petrol fumes to the outside?? especially if it is not connected to a valve you will soon have quite a mess....

just connect the charcoal canister with valve to inlet manifold, sure the 1.8t has a suitable connection...

[benvictors]

The mk2 doesn't have a carbon canister and there isn't anywhere to put one in the bay, especially the big bulky mk4 canister, could possibly look at fitting a mk3 canister but again you are kind of limited on space.

Have a look at this
http://www.golfgtiforum.co.uk/index.php?topic=222678.0

[itavaltalainen]

And why would you want to del the canister? I would just find some space for it somewhere else.

[benvictors]

^^ Because it does nothing for the running/performance of the engine and creates an irritating ticking sound, the canisters themselves are also big and ugly. The only reason they are in the car in the first place is for environmental purposes, and if you are putting a 1.8T in a mk2, odds on you aren't gonna run a cat, in which case you probably dont really give a monkeys about throwing a few extra petrol fumes into the atmosphere 

[richking]

Thanks for the replys guys, no I don't really have room for the canister so ill put a one way valve on and hide it somewhere.