Fuel vent leaking

[icemanrd19]

Is it normal for some fuel to mist out of a fuel vent? Im running the Finch performance dual vent system that is mounted in my trunk and after going on for some spirited driving and parking the car you can hear and see fuel mist coming out of the vent. Any idea what it could be? 67 camaro ls3, Ricks notched corner tank with new camaro fuel pump.

FYI we have this system on 2 other cars and experiencing the same thing.

[130fe]

How full is your tank? I experienced this when autocrossing with a near full tank on my II Much vent. Stopped after I burned some gas. Lesson learned, don't autocross with a nearly full tank of gas........ ;-)

[icemanrd19]

Yea mine was pretty full. Chris I'm wondering if it's bc of our 67 and 68 the filler neck is higher than the vent box, or too full of a tank, or a combo of both

[68Cuda440]

Yea mine was pretty full. Chris I'm wondering if it's bc of our 67 and 68 the filler neck is higher than the vent box, or too full of a tank, or a combo of both

Could be. Is it possible the fuel gets up there when you are filling the car? Is the vent hose looped up higher than the filler neck?

[Finch]

Yea mine was pretty full. Chris I'm wondering if it's bc of our 67 and 68 the filler neck is higher than the vent box, or too full of a tank, or a combo of both

Full tanks and agressive driving will make fluid go places it normally wouldnt, but we should be able to correct this. Is your vent line coming off of the tank or the filler neck? May need to move the tank higher up in the trunk (I can send you some mounting brackets) and then run the filter remote to the outside of the car.

On my car I mounted the canister high in the trunk and ran a poly 1/4 inch vent line off of my filler neck to the canister to prevent this. The tank installed vents are often below the fluid level when the tank is topped off.

Also if you run a line larger than -4 or 1/4 inch to the canister, you will get fluid movement which then gets carried to the canister as the tank vents.

[icemanrd19]

Full tanks and agressive driving will make fluid go places it normally wouldnt, but we should be able to correct this. Is your vent line coming off of the tank or the filler neck? May need to move the tank higher up in the trunk (I can send you some mounting brackets) and then run the filter remote to the outside of the car.

On my car I mounted the canister high in the trunk and ran a poly 1/4 inch vent line off of my filler neck to the canister to prevent this. The tank installed vents are often below the fluid level when the tank is topped off.

Also if you run a line larger than -4 or 1/4 inch to the canister, you will get fluid movement which then gets carried to the canister as the tank vents.

Vent line is coming from the side of the tank using -6 line. I have a port on my filler neck that I could use as well if needed but it's plugged now. I'll give the bracket a try to try and raise it some. I can run a grommet to seal the vent going back outside. I'm willing to give it a shot and see if it fixes it.

[HandOverFist]

I'll throw this out here just for the heck of it...do not loop a vent line.

[JohnUlaszek]

Since the II MUCH product was brought up I'm happy to speak to specific issues related to it. Several things can lead to this which can all be addressed, but the easiest thing to do is not top off the tank before you autocross or road race.

We update the installation instructions whenever we learn something new, so this is a good starting point for resolving issues with the II MUCH product. And you can ALWAYS give us a call and we will work with you to resolve any issues. 888-216-6033.

[JohnUlaszek]

How full is your tank? I experienced this when autocrossing with a near full tank on my II Much vent. Stopped after I burned some gas. Lesson learned, don't autocross with a nearly full tank of gas........ ;-)

Its possible to run with a full tank, but we will need to know more about your current setup to diagnose the problem. Give us a call 888-216-6033.

[frankv11]

I made my own set up from scratch , uses activated carbon for clean garage smell and experienced same leakage when I threw the car around a bit so I installed a roll over fuel safety in line valve . I installed it on a vertical position so that tank would breath under normal conditions and incase a gush of fuel it will close , worked out perfect for me.

That's where mine sits , want it mine up high and out of the way

[icemanrd19]

strangly after i posted this i have yet to have another issue lol

[andrewb70]

I made my own set up from scratch , uses activated carbon for clean garage smell and experienced same leakage when I threw the car around a bit so I installed a roll over fuel safety in line valve . I installed it on a vertical position so that tank would breath under normal conditions and incase a gush of fuel it will close , worked out perfect for me.

That's where mine sits , want it mine up high and out of the way

Mind sharing what is inside that canister?

Andrew

[frankv11]

Repourposed co2 tank cut and removed about 5"' of length , put the guts in there and weld it . Activated carbon filter padding held by perforated aluminum cover to keep all particles out fuel line and breather , filled it up with activated carbon particles ( so you can pour / service )from any pet store. I could have done without the STainless steel / AN fittings / bungs etc to keep cost down but it would not look as cool.
No gas smell in garage , tank breaths just fine , no problem when topping of tank, fully serviceable I'm very happy with it ,

[ULTM8Z]

On my setup (using a Tanks EFI tank), I drilled and tapped a 1/8" NPT hole very near the top of the filler neck. Then put in a 90° 5/16" hose barb and ran the factory charcoal cannister vent line to it.

For the air inlinet, I use a third gen Camaro "mushroom" fresh air valve that hooks up to the vent port on the fuel tank sending unit.

Runs perfectly... no overpressure or underpressure in the tank, no fuel smell in the garage, no liquid fuel getting sucked into the vent line.