1975 fj40, new gas tank and lines, stock fuel separator, in-line stock check valve off of separator (works as one way valve) in correct orientation, desmoged but p/o eliminated charcoal canister, bvsv and vsv. Stock carb.
When run even for a short period of time there is substantial positive pressure build up on the gas tank, when the cap is removed it is dramatic, not just a “swoosh.” I’m getting ready to install a aftermarket ac delco canister to deal with gas fumes, was going to attach to air cleaner since switched vacuum ports are missing.
THE PROBLEM
Why won’t the tank vent through the check valve coming off of the separator? I can easily suck gas fumes through the hardline on the down stream side of this check valve (can not blow through it). Does it need the vacuum through the cc? Am I missing something?
When run even for a short period of time there is substantial positive pressure build up on the gas tank, when the cap is removed it is dramatic, not just a “swoosh.” I’m getting ready to install a aftermarket ac delco canister to deal with gas fumes, was going to attach to air cleaner since switched vacuum ports are missing.
THE PROBLEM
Why won’t the tank vent through the check valve coming off of the separator? I can easily suck gas fumes through the hardline on the down stream side of this check valve (can not blow through it). Does it need the vacuum through the cc? Am I missing something?