Solving fuel venting issues

[ManKrawler]

I have an 8 gallon Jaz fuel cell under the back seat of my SXS. The stock tank will not fit into the chassis anymore. It has been in there for 2 trips now. The first trip was a mess, with the coolant lines right under the cell it was constantly venting fumes and fuel out the vent line, re-routing the vent did not help I had to just deal with it. The fuel was boiling.

After relocating the coolant lines, heat shielding their entire length, heat shielding the tank, and re-routing the vent I was certain this was fixed, took it out yesterday and it was fine most of the day until after 15 minutes of pulling a grade the smell was there and I could watch fuel blow out of the vent in my rear view mirror. The tank was not hot, warm, but nothing I am worried about.

The factory tank had a vented cap, I am now using a Jaz neck with a sealed cap. Using the factory sending unit with a hydramat adapted into the Jaz cell, and a 8 an roll over vent valve is towards the back of the tank. Pulling that grade the fuel is at the back of the tank and I imagine the roll over valve is submerged. The fuel neck is also towards the back of the tank.

I blew into the line and it is clear, pull the cap and get a woosh and see fumes venting.

Read Billavista's article and see his, and others, recommendations:

Will this fix it? Anything else I should do? SXS are ghey?

 

[Bebop]

Remove rollover valve.
Do the FATS system with 1/2 hose or bigger.

Make sure the hose end is lower than the bottom of the cell.

 

[gt1guy]

Four sides and down.

Run the vent around the perimeter of the cell at the top, then drop it down to below the bottom

 

[94toytruck]

Mine will do that if I overfill it. I have a remote fill and fuel will lay in the neck which is actually higher than vent line. Fuel heats up a bit cause my radiator blows on the cell and it spits a little fuel out the vent. My cap was vented but it's right next to my head so I welded over the vent hole. I'm not sure if my cap was vented it would change anything though since I have a flapper in my fill.

I have absolutely no issue if it's not over filled. It fuel is above the flap valve in the neck it does it every time. I have a FATS system like above with a roll over valve at the fuel cell and a ball valve above my head to close the line if needed. I have a Jaz 16gallon cell mounted low, remote fill and FATS running up around my B-pillers and down with a ball valve in the middle of the roof line.

 

[realsquash]

Honestly I think it's working fine as-is. The tank needs to vent and these convoluted setups with lots of tubing and all that will not prevent fumes from venting out of the tank. If you don't want any fumes then rig up a charcoal canister and do it the right way.

 

[ManKrawler]

Seems to be solved, a few things done though.

Noticed the coolant lines for my intercooler radiator were touching the fuel lines in a spot, that was the obvious cause of the cell feeling warm last trip out. I think a zip tie broke, I do not recall leaving them like that. Built a floor in between the two sets of lines with heat shielding mat 3M adhesive sprayed to the coolant line side to reflect the heat away.

I left the 8an roll over valve, which is just a standard JAZ product, and installed a 3/8" vent line like Billavista shows going side to side past the cell and running upwards before turning all the way to the ground. I found a slick way to run it and really think that was a big change.

During this last trip I kept the fuel cell topped off always, fuller than I have ever run it, no issues. There is no smell of fumes as they are venting at the ground, and I saw no leakage, even when I ran out of talent.

I do notice that the poly cell has warped inside the can, a lot, from the heat during all of this trial and error so going to order a replacement and install a larger roll over valve just in case. Should be good to go from there.