fuel venting system modification

[Oldguyinajeep]

Out in the Colorado mountains a few weeks ago, I noticed gas dripping from the left rear of my CJ7. It was coming from two rotten fuel lines coming out of my gas tank, and were attached to a pod, which was attached to another pod, which had another fuel line going somewhere.

I've since learned that this is my fuel vent system, and that the two pods are a rollover valve, and a liquid check valve. I replaced the leaking lines, and this caused a pressure buildup in the gas tank, which produced hissing at the gas cap, and belching of vapor and puking of gasoline when the cap was removed. Obviously, the vent system wasn't working.

So...the adventure began. This is a write -up of my solution. I've searched several forums, and followed many dead ends. First, the valves: Delorean makes a replacement liquid check valve which many have used. It looks like the mounting bolt location is identical. You can also find replacement rollover valves. The solution I chose is a valve which takes the place of both. It's made by MTS, and it's the JLCV-1. They state that it will perform both LCV and rollover functions. It looks like somebody makes these in their basement, but the reviews are good.

The valve comes with a brass tee at the bottom. In this pic, I've added two small lengths of hose and a couple of 90 degree connectors to get the lines going the right direction. It comes with the pictured mount, which just requires drilling one 1/4" hole.


https://www.jeep-cj.com/forums/photo_popup.php?e=vB_Editor_001#

This picture shows the valve in place, as I'm fitting it.

https://www.jeep-cj.com/forums/photo_popup.php?e=vB_Editor_001#

The metal edges of the fender support worried me a little, so I wrapped the fuel line in some clear tubing, and taped it in place, where they might come in contact with the edge. I also bent the metal edge upward on the inboard side. I drilled another small hole in the fender support, and nylon tied the outlet line of the valve, for extra support.

https://www.jeep-cj.com/forums/photo_popup.php?e=vB_Editor_001#

Now for the vapor canister. There are lots of old posts which feature part numbers which would be "near-exact" replacements. That is, they have the same number and sized ports as the OEM canister ( CP-1061,3045, 1022, and 1109). The problem is, they are no longer available. At least anywhere I could find. What I wound up using was based on one solitary post (in this forum, I believe). My apologies to the author for not writing down his name. He used a Standard CP-1039, which only has three ports. The one labeled "tank" goes to, well... the tank. The one labeled "purge" goes to vacuum (pvc line in my case, since I have a Howell TBI set-up). And one is the air intake. It could be connected to the air filter, but also has a splash guard on it, which can be left in place so that this becomes the air intake, which is what I did. The bottom is enclosed, unlike the OEM canister which has its filter there.

https://www.jeep-cj.com/forums/photo_popup.php?e=vB_Editor_001#


I absolutely cannot believe how much better my jeep runs. I wish I had done this long ago, but honestly, this vapor system is just something I ignored. Live and learn.

Another note: Apparently if emissions are not an issue where you live, or in your belief system, those two lines coming out of the gas tank can simply be plugged, and you can go get yourself a vented gas cap and be in business.

 

[Scout1067]

Now for the vapor canister. There are lots of old posts which feature part numbers which would be "near-exact" replacements. That is, they have the same number and sized ports as the OEM canister ( CP-1061,3045, 1022, and 1109). The problem is, they are no longer available. At least anywhere I could find. What I wound up using was based on one solitary post (in this forum, I believe). My apologies to the author for not writing down his name. He used a Standard CP-1039, which only has three ports. The one labeled "tank" goes to, well... the tank. The one labeled "purge" goes to vacuum (pvc line in my case, since I have a Howell TBI set-up). And one is the air intake. It could be connected to the air filter, but also has a splash guard on it, which can be left in place so that this becomes the air intake, which is what I did. The bottom is enclosed, unlike the OEM canister which has its filter there.

That was me that found the CP-1039. Took me forever, some measuring tape, and a few phone calls to figure out that it would work. I am glad my research helped someone out. The cross-pollination of ideas on this forum has helped save me some serious headaches working on my CJ, I am glad to see I can also contribute instead of just sucking knowledge.

Here is my original post: What did you do to or with your CJ today? - Page 651 - Jeep-CJ Forums

 

[jfmcj7]

I have more or less the same problem with my CJ. Will have to look into this. Thanks for the info.

 

[jzak]

Could you add some pics of the installed vent? The links you added don't work for me. I've got the same problem, but the part you recommended looks nothing like the rusted-out liquid control valve I have on my CJ5. Would be nice to see how it hooks up. Thanks!

 

[Oldguyinajeep]

jzak,

I wish I could, but I can't figure out how to do that. I uploaded the images to my gallery, and added them to the text, using the "add image" feature in the "My Gallery" box, and this is what came up. I did a drag and drop. I've previously added images without this issue, but can't figure out what I'm doing differently. Any input from forum members would be helpful. Whomever is in charge of the "contact Us" email has not responded to my request for help.

 

[Oldguyinajeep]

jzak,

I found a convoluted way for you to view the images. Go to "Members", find me, "Oldguyinajeep", and scroll down to view the images in my gallery. You'll find a pic of the valve there, and can select it to view enlarged.

Keep in mind that I have added the 90 degree elbows. What you get from the supplier ends with the brass "T".

 

[jzak]

jzak,

I found a convoluted way for you to view the images. Go to "Members", find me, "Oldguyinajeep", and scroll down to view the images in my gallery. You'll find a pic of the valve there, and can select it to view enlarged.

Keep in mind that I have added the 90 degree elbows. What you get from the supplier ends with the brass "T".

Thanks for trying buddy! The way I add pics is when you reply to the thread, there is an additional options section below, where there is a box that says Attached Files. Click on the Manage Attachments button. There should be a pop-up box, then select the pics you want, then click upload. It should take a few moments for it to upload. Then just hit submit at the bottom of the page.
I hope that helps.

 

[Oldguyinajeep]

ok, if I did this properly, you should see images as attachments. They will match-up with the descriptions in my original post. Thanks for the help!

 

[jzak]

ok, if I did this properly, you should see images as attachments. They will match-up with the descriptions in my original post. Thanks for the help!

Thanks, bud! I just had a question. I'm assuming the two hoses connected to the bottom t-shaped fitting goes to the gas tank, but where does the hose on the top of the vent go to? Can I also ask what is that stuff you have taped on the hoses?
Thanks!

 

[Oldguyinajeep]

The line coming out of the top of the valve goes to the vapor canister. It is connected to the port labeled "tank" on the one I used.

The protective wrap is just some clear tubing that I had left over from some other project. It can be purchased at Home Depot, by the foot. I just split it, placed it over the fuel line, and electrical taped it. Probably overkill.

 

[Basod]

Thanks for the write up on this. I was just under the left rear fender trying to discern which line to use for a return off my filter.

My Jeep was originally a 4cyl and has a 1/4” and 5/16” line down the DS frame rail- you have to look at them close to tell.

The 5/16” goes to nowhere in the engine bay and is attached to some of the rollover canister under rear fender the 1/4” is connected to carter yfa bowl vent and to tank with an additional fuel filter- PO head scratcher.

5/16” line is full of transmission fluid acetone mix after an air blow before reconnecting to the tank vent.


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