1970 fuel tank vent and return (1 Viewer)

[Dave54000]

I have a 1970 fj40 I have to pull the tank to reseal and figured while I am at it instal a return line fitting for sniper eventually and a vent for a charcoal canister. Question is can I use the existing vent for cap system tie in into just new vent and return and where's best placement thanks

 

[Jdc1]

I have a 1970 fj40 I have to pull the tank to reseal and figured while I am at it instal a return line fitting for sniper eventually and a vent for a charcoal canister. Question is can I use the existing vent for cap system tie in into just new vent and return and where's best placement thanks

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On our ‘72, I tee ed into the filler vent for the return and then use a vented cap. No issues.

 

[Mark Jennings]

Question, why install a charcoal canister for the vent? These old girls are vented through a small hole in the filler neck, just under the gas cap.

 

[Dave54000]

Question, why install a charcoal canister for the vent? These old girls are vented through a small hole in the filler neck, just under the gas cap.

To get rid of fuel smell and i believe sniper works better with charcoal set up for tank

 

[Mark Jennings]

A charcoal canister is actually a dynamic device. The activated charcoal absorbs the vapor, generally when parked, then it needs airflow to reactivate. That’s why most vehicles have a vacuum line back to the manifold. It pulls fresh air in from a secondary check valve located on the canister…..
Plus most charcoal system have some sort of expansion tank, kind of a storage container in a cool spot, to allow condensed vapors to drain back to the tank.

Besides the complexity, oily and gasoline smells are just part of the ‘charm’ of owning a pre-emissions Land Cruiser.

 

[Dave54000]

A charcoal canister is actually a dynamic device. The activated charcoal absorbs the vapor, generally when parked, then it needs airflow to reactivate. That’s why most vehicles have a vacuum line back to the manifold. It pulls fresh air in from a secondary check valve located on the canister…..
Plus most charcoal system have some sort of expansion tank, kind of a storage container in a cool spot, to allow condensed vapors to drain back to the tank.

Besides the complexity, oily and gasoline smells are just part of the ‘charm’ of owning a pre-emissions Land Cruiser.

Thank you

 

[Jdc1]

FWIW- I have an unvented correct ‘72 cap for when it’s being shown, if I forget to swap to the vented cap the Sniper loses power on acceleration after about 30 miles. Not much fuel smell with the vented cap in the garage.