gas tank vent
 

I was seeking a pro answer on this....

a high pressure and low pressure system..both using the same tank. For manufacturing cheapness, the low pressure system has a cheap tank.

Respecting vents, charcoal canister.. I noticed a problem unfolding, related to venting.. in the back, an odor.
as it turns out I have a flawed tank, no rupture, simply made badly (if you have a carbed subaru, you may have one too...)

The gas cap is vacuum only no vent..

Today, missing an appointment to get the tank done (remove replace), I saw the 90 degree mark coming and finally just stuck a hose between the seam of the car and the tank and let it have it with some metal silicone I had in the back.. (I have possibly more than a week to go now)

the hole was so small, that light gasses escaped, rather than gasoline.This soemhow dropped my mileage by ten or more...a venting pinhole...

I am curious as to when putting new tank in, if having a vent up tup, the very top, real small, like the errored hole with the current setup would help it, or hurt it...be it from my own lesson, there can be no venting at all, to gather the light gas for mileage, else, it escapes. :rolleyes:

i am not understanding the question