Escort Cosworth's have what I'm told is a 'Purge Canister System' which looks to vent from a small pipe on the top of the fuel tank to what looks like a valve which leads to the front of the car (nearside inner wing) to another valve which has a pipe to the inlet manifold and a pipe to a caninster under the offside front arch.

What exactly is this for? I'm guessing its a way of drawing fuel vapours into the canister but why? to stop the fuel filler cap hissing when you remove it? or for an environmental reason?

The inlet manifold pipe has been blocked ever since I've owned the car so I doubt it works anyway and I was intending to remove all of it, is there any reason why I shouldn't?

emissions is it's purpose
be careful if you remove it
the tank vent which is what it actually is, must not be blanked
it performs fine as standard so there is no reason to remove it

Ok you have now scared me into not removing it

Why do people block the inlet pipe to the system?

it's part of the recylce system to get it through it's emmisions testing

if you don't need to pass the cat test then it'll be ok, but there is a lot of crap that goes with it which might make the tester think twice as to weather youshould have a cat on there or not

make sure the cars had a spanking and it's up to temps before you go and it shouldn't be a problem

LOL well i ripped mne out the other night and blocked it lol.I think il unblock it lol.So the pipe the purge came off can go and u jjust leave the pipe free??

not for emissions as far as i know.will probably be corrected if im wrong lol, its just for the enviroment ie on overun when not on throttle the solonoid will open drawing the vapours from tank into the inlet to burn rather then vent to the atmosphere ??? just run a pipe elsewhere away from exhaust/heat etc if your gettin rid [/code]

Then surely the car will rev on its own when your changing down gears to slow down at a junction?

of 'vapour'? i doubt it. most probably speed dependant also

Hmmm, did anyone ever tell you that the "vapour" is the most volatile form of petrol?

nope lol didnt realise that. id like to know exactly how it works then. thats the impression i always had. at what point does it let it in then?

Blatant copy and paste:




Fuel Tank Vent Valve

In the context of motor vehicles, a device that vents fuel vapours into the inlet tract of the vehicle's engine during running.

While parked, vapours released by the contents of the vehicle's fuel tank are collected, usually in a charcoal canister of some sort. During engine running these gases are released into the combustion system by the fuel tank vent valve.

To ensure the engine runs correctly when it is cold or idling, and to protect the catalytic converter (if fitted) from an over-rich fuel mixture, this may not occur until the engine has reached a particular temperature, or until it is operating under a certain load. This factor is determined by the vehicle's engine management system. After this initial opening of the valve it is modulated open and closed while the engine is running.

On older vehicles without computer control of the fuel, exhaust and ignition system the same venting system may be controlled by a vacuum pipe to the inlet manifold.

The valve, when present in a vehicle, can also be used to double as a pressure release valve for the fuel tank; without such a valve the fuel tank could eventually implode from atmospheric pressure as fuel usage causes its internal pressure to drop.

It's fine to remove it (think it sits inside the wing on an Escos) but as Tony said, the vent pipe from the tank should not be blanked off in fact it would be better to chop the pipe at the tank end and let it breathe from that area rather than the engine bay.

You wernt far wrong pal, just it lets it in on acceleration, not over run

Thats the same as what i did.
Removed the tank and all pipe work back to the fule tank, and then cut the line at the fuel tank end so it vents to air.