Vent Line

89oem · Aug 20, 2016

So in seeing Jeff's vapor lock pump issue and talking about tank venting, I currently just have my vent line running to the passenger fender well and open - hidden well but the passenger gets to breath in fumes even with the top down sometime,

How is everyone routing their vent lines??

Davedacarpainter · Aug 20, 2016

Good question. On my red car I was wondering what I might do about that.

I'll be carbureted and all those electric lines were cut out, so just running it to a new canister wouldn't really help.

MikeH686 · Aug 20, 2016

Why can't you run drill a hole next to the fuel cap but still inside the gas tank lid and run it up to there? I did that with the breather hose on my Tacoma for the rear axle since I off-road it alot

90sickfox · Aug 20, 2016

To my knowledge the line should be hooked to a vacuum source....or you can plug it and use a vented gas cap. If you ran it to the filler neck it would still cause vapor lock in the tank.

On dual port pcv valves for carbed cars one port went to the charcoal canister and the other to intake vacuum port.

MikeH686 · Aug 20, 2016

How can it vapor lock when it's constantly vented to the atmosphere

89oem · Aug 20, 2016

So my research shows, the standard fox gas cap serves as an air inlet- to balance the tank "volume", the vent allows pressure release along with gas vapors -and without the factory charcoal canister and intake feed thats where cabin fumes come from . With a high volume pump it generates excess heat, pressure and vapor, that super heats the fuel which causes the cycle to build on itself and end result vapor lock since the pressure builds quicker than the stock vent line can release, so Im thinking I want a better vent and to move it away from the front of the vehicle.

Of course Im just a layman

Ive read a few great ideas, Im still reading though,

stykthyn · Aug 20, 2016

Iirc isn't that what the charcoal canister is for? I reinstalled mine along with the solenoids. huuuuge difference in the way I smelled stepping out of my car.

stykthyn · Aug 20, 2016

*edit* I forgot you are running a coyote

90sickfox · Aug 20, 2016

Didn't know this was a coyote, either. I'm still playing on the little play set....not big enough to play with the big boys yet...

On newer cars the vent valve allows fresh air in the canister and the purge valve allows vapor to be burned off.

My carbon canister is going to be relocated to behind the rear bumper support.

The vapor hose is never connected to a constant vacuum ( did further research ). Seems most vehicles apply vacuum to the line at idle, deceleration, and at cruise- under vacuum.

Basically, a vacuum solenoid would need to be set to come on at and below a certain throttle position. The canister holds vapors in the charcoal....so it seems like it would be safe to release vapors when throttle is shut. When vehicle is not running the purge valve needs to be closed. The carbon canister will trap vapor....when started the valve should open venting the canister. Guess they shut it off during acceleration and under loads to take the fuel trim variables out of the equation.

I don't know what this would do to idle fuel trims.

Hope someone can figure a way to plumb a canister and purge valve in a custom car configuration.

89oem · Aug 21, 2016

@90sickfox Thanks for that, at one point I had thought about hooking up a canister and line to the intake. But was unsure of some the details of how it would end up working, as Im sure Ford's engineers just dont wing it...

Right now what Im thinking is a larger rollover AN fitting on the tank (remove stock and mount new one). a coiled vent line and small fuel safe breather on the end mounted at rear of vehicle somehow,

The coils apparently cut down on the vapor - guess its like a still. the vapor will condense and fall into the coils and back into the tank, so no fumes.....

89oem · Aug 21, 2016

Guess I should have clarified engine, but I didnt think it mattered as there are allot of combos with this issue...

TOOLOW91 · Aug 21, 2016

Im curious to see what you come up with. Over winter i have to pull the tank for an unrelated issue but i did want to do something with the vent to cut down on the smell.
Also when you flowing close to 2.5GPM on a real hot day that fuel super heats quick LOL.

Farrell5.0 · Aug 22, 2016

I don't even remember where my vent line is lol on a side note, I drove my car on Saturday, it was about 90 by time I got back home from cars and coffee and my pump was running LOUD (stealth system with in-tank a1000). I usually can't hear it over the blower/exhaust at idle and I could hear it working, there was about 2/3 fuel left in the tank. I don't have my fuel pressure gauge hooked up yet, wide and was reading lean at idle, normal while driving. It appears these pumps don't like hot days.

Bullitt347 · Aug 22, 2016

I have a 3/8" hose coming off of a roll over valve. The hose is coiled/looped 2 1/2 times, about the diameter of a 3 lb coffee can. This just lays on top of the tank with the end of the hose open. I am using the original stock gas cap. I smell no fumes in the garage. Even with Q16 in the tank, I smell no fumes. And if you have ever smelled Q16, you would know if you had a fuel vapor leak. That stuff is dangerous.

89oem · Aug 22, 2016

Bullitt347 said:
I have a 3/8" hose coming off of a roll over valve. The hose is coiled/looped 2 1/2 times, about the diameter of a 3 lb coffee can. This just lays on top of the tank with the end of the hose open. I am using the original stock gas cap. I smell no fumes in the garage. Even with Q16 in the tank, I smell no fumes. And if you have ever smelled Q16, you would know if you had a fuel vapor leak. That stuff is dangerous.

Nice!

This is what I was hoping to hear!!

So you just laid the coils flat so they wouldnt create a plumbing style P-trap that blocks fumes from escaping?
Did you just use the factory vent nipple or did you get a larger one and mount it?
-if so can you walk me through what you did...

One minor change I was thinking of putting a breather style filter on the end to stop dirt and dust from entering the tube -

Thanks!!

Bullitt347 · Aug 22, 2016

The plastic elbow that has the vacuum hose on it for vent is removed from the grommet. Then this: https://fuelsafe.com/catalog/cat-images/ITVV06-90.gif or similar, is installed. It fits the factory grommet. Then a 3/8" (or -6an) hose is attached and looped/coiled like mentioned. The filter on the end is a good idea.
:

89oem · Aug 22, 2016

Yaaa, I was reading threads where they removed the fitting and did this whole new washer type fitting expoy'd on and was a little leary of that idea...

Ill get the parts and jump right on it,

So 3-4' of hose should be plenty I'd guess

Thank you again!!

89oem · Aug 23, 2016

@Bullitt347 one last questions, do you have any burping or overflow when youre filling it up or when its full? edit: from the vent line,

Im assuming no but thought Id ask,

HotFox · Aug 23, 2016

I have a 1/4" hose off mine that just runs forward off the tank, it hangs just lower then the seam. I always notice it slightly moist on the end but never a smell in the garage. To me anyone that says they smell fumes must not have a generator, rotor tiller or tractor in their garage. All vent to atmosphere, with no smell.

And never have a issue with over filling the tank.

Bullitt347 · Aug 23, 2016

89oem said:
@Bullitt347 one last questions, do you have any burping or overflow when youre filling it up or when its full? edit: from the vent line,

Im assuming no but thought Id ask,

No issues fueling the car. No issues using the fuel either. The engine burns through a 1/2 gallon of fuel in just over 5 seconds, so it is using the fuel faster than when I am putting it into the tank Lol.

Vent Line

Mustang Master

Chicks can make things hard if they’re inspired...

Mine is only two inches though.

Wasn't a pretty sight...and I've got big hands

Mine is only two inches though.

Mustang Master

I want to measure mine. It doesn't look that tall.

I want to measure mine. It doesn't look that tall.

Wasn't a pretty sight...and I've got big hands

Mustang Master

Mustang Master

If you're the village idiot what's that make me?

Not sure what "DP" means, but know's he likes it!

I have been doing it wrong this whole time

Mustang Master

I have been doing it wrong this whole time

Mustang Master

Mustang Master

I have been doing it wrong this whole time

Similar threads

Privacy & Transparency

Privacy & Transparency