Pandor

Hi,

I'm about to remove the charcoal canister from my CRX, and I was wonder if I should place a one way valve on the breather hose from the tank, to let the fumes out. but not take air in.

Wouldn't leaving the nipple at the firewall free-to-air be a vacuum leak (since it's behind a 2-way valve)?

Or isn't there supposed to be vacuum in the fueltank?


I was under the impression that the charcoal cannister was in a closed loop, so there had to be vacuum in the fueltank. But then I noticed another hose, on the bottom of the charcoal cannister (which doesn't show in the vacuum diagram). So it pulls in air that way?

Justin91civic

Ok the fuel tanks builds up pressure so what that canister does is to take in that pressure and store it in the canister until the car is warmed up. Then the car tells the canister to open and it sucks the fuel vapor into the car and burns it during the normal cycle. If you remove the canister it will not help anything and be harmful for the enviroment.

Pandor

I know how the charcoal canister works, but what I would like to know is what happens when the fuelpump sucks fuel out.

You get vacuum in the fuel tank, so is there supposed to be vacuum in the tank, or is it compensated by sucking air in somewhere?

Justin91civic

There is a vent tube that connect the fuel filler to the fuel tank. When the car is sucking fuel using the fuel pump the gas cap will release some of the pressure and suck air in thru there. But no that line that you are wanting to block off is for the pressure to go into the canister. Check out andrews engine swap thread on this web site in the auto/multimedia he has shaved pretty much everything in his car on his firewall. If it does not show how he disconnected the canister then pm him and ask him how he had done that. The thread that he has on here is over 2000 posts and has alot of detailed info. So check that out and see but with my car I have not done any of the tucking or shaving yet.