Fuel Vent Tube Question
 

Hey there -

Our '62 Ford has an OLD style fuel vent - a 1/4" steel line that runs from the tank, up the filler neck, and out to the atmosphere next to the gas cap. Now that we're running a return-type EFI system, the returned fuel seems to create some agitation in the tank and the vent just spews vapors as you drive. Aerodynamics make the vapors move forward, so you smell them all the time in the car.

Any ideas on installing some sort updated vent? Charcoal cannister?

Thanks in advance!

- Kevin

you could use a Fox body 5.0 mustang canister (or any , this size seems to work on most cars), run the vent from the tank to the caniser and the other side to the engine vacuum source somewhere.
Should take care of it !

That's a good idea, but the vent is behind the rear license plate. This would make for a rather long vacuum line... the canister would have to go under the trunk floor somewhere. Thoughts?

Yes it would be long but I think it would help you out.
Most Factory newer cars are like this also .

I guess a 1/4" hardline on the frame rail would do... I have to see if the original fuel line is still there... that would work. Hmm.

Thanks for the idea!

OK - here's another idea to chew on.

How about just extending the vent tube using some rubber fuel line (or similar) and placing the exit in a more aerodynamic location. Do you smell exhaust all the time? If not, put the vent in a place similar to the exhaust pipe.

That's also a good idea. I guess in the old days, the vent tube allowed for the fuel level to decrease in the tank without creating a low-pressure or vacuum situation in the tank. Now, it is truly a vent, and we smell gas all the time.

However, we don't smell exhaust.

I like the idea of re-introducing the vapors into the engine, and I can program the ECM to activate the purge solenoid on a late model charcoal can, I'll just have to locate it.

I'll do it when we build a small surge tank to fix the fuel slosh starvation issue.

Thanks for the suggestions... keep 'em coming!

- KO

You will still need a vent for the same reason: to allow air to replace gas as you drive.

I made a vapor/air separator, hooked it to the tank, then attached the air output of the separator to a K&N crankcase breather filter. Works fine.

jp

Sounds cool, John. What did you use to make the separator? Do you have any pics?

Thanks,

Kevin Oeste

Kevin,

I made it out of two pieces of aluminum tube, one inside the other. Here's a thread on PT.com with a pic in it (I can't find my own copy any more).

http://www.pro-touring.com/forum/sho...ight=fuel+vent

The breathers are mounted upside down on the underside of the trunk so that any smell would be outside the car. You can see the lines going to them. The other line is the rear housing breather.

jp