CJ gas tank tech, please help

[dbozman]

Application is an '80 CJ5 with four-banger. Old tank leaked like a sieve. Got new replacement tank at 4Wheelers. Here is how stock tank WAS lined in (which I think is incorrect):

Tank has a total of four necked outlets. Two outlets are on top where the float and whatnot enter the tank. Two are on the driver's side that lead to the rollover valve and stuff.

Old tank was lined with rubber feed from main gas line into one outlet atop tank. The second outlet atop tank had some sort of check or two-way valve on a rubber line.

The two side outlets went to the rollover valve equipment mounted under the DS rear fenderwell. These plastic pieces are lined together. One routes out to the charcoal canister in the engine bay. The other routes to what I take is the hard return line (stock hardline next to the main fuel hardline).

Does this make sense?

I think the top outlets should be attached to the return line and main line. Can anyone confirm?

Also, are the components like the rollover valve and other stuff attached externally to the tank really necessary? They're all a mess. Could I just route a couple of hoses up there with some sort of check valve on them?

Any tech help appreciated as I want to do this correctly the first time. Thanks.
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[idontknow]

Go Buy A Manual!

[dbozman]

Great idea, man, thanks for your help.

Meanwhile, if anyone has any actual tech knowledge they can offer, I'd much appreciate it.

After looking at the entire system again, what I had taken to be the hard return line is, in fact, a hard return line, but it routes from the charcoal canister under the hood, which has an overflow line from the carb. Shouldn't that return line be dumped directly back into the tank instead of routed through the rollover/whatever stuff underneath the fender?
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[Genedil]

The line running into the charcoal canister is to dispose of fuel vapors in the tank that would normally be vented into the air. The line from canister to carb is to burn these vapors off. Thank the tree huggers for your confusion on this one.... who really wants an ozone anyway

[Genedil]

Oh sorry forgot about the fourth line with the check valve... This one "should" have been to allow air into the tank as you ran the fuel lower to keep the tank from becoming a huge vacuum can. Can anyone confirm all of this, I know this is how it has worked on every vehicle I've owned but you never know...

[dbozman]

Interesting. So you're saying the second hard line (the one that ultimately routes into the underhood canister) isn't a "return" line but a "fumes" line? And the line from canister to carb isn't to dump carb overflow into the canister, but gas fumes from the tank into the carb?

I had it *** backward, I guess.

Couldn't the second outlet on top route into the "fumes" line? Couldn't I then do away with the rollover and other items under the DS quarter and just route a couple soft lines with a filter or something?

Effect on AZ emissions? Thanks.
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[shocker75]

Go Buy A Manual!
That is probably the best advise ever given on this board. Especially if you can get the factory/dealer service manuals. These are priceless for older vehicles.

[Genedil]

Like I said, I'm not 100% sure, but I'd definately put money on it. The manual will definitely clear everything up just to be certain.

The canister is a piece of the emissions requirements so removing it will cause you problems. But you may be able to get around that with some creativity.

Arizona Law for Classic Car Emission Exemption from http://www.hagerty.com/NewsManager/templates/template_adv.aspx?articleid=1167&zoneid=3

HB2357 defined a collectible vehicle as a vehicle that either (a) bears a model year date of original manufacture that is at least fifteen years old, or (b) is of unique or rare design, of limited production and an object of curiosity, and also is both (a) maintained primarily for use in car club activities, exhibitions, parades or other functions of public interest or for a private collection and is used only infrequently for other purposes; and (b) has a collectible vehicle or classic automobile insurance coverage that restricts the collectible vehicle mileage or use, or both, and requires the owner to have another vehicle for personal use.

Just call up your insurance company and get quotes for classic car insurance and you can remove your entire emissions system to include the cat

[Frisbie]

Like I said, I'm not 100% sure, but I'd definately put money on it. The manual will definitely clear everything up just to be certain.

The canister is a piece of the emissions requirements so removing it will cause you problems. But you may be able to get around that with some creativity.

Arizona Law for Classic Car Emission Exemption from http://www.hagerty.com/NewsManager/templates/template_adv.aspx?articleid=1167&zoneid=3

HB2357 defined a collectible vehicle as a vehicle that either (a) bears a model year date of original manufacture that is at least fifteen years old, or (b) is of unique or rare design, of limited production and an object of curiosity, and also is both (a) maintained primarily for use in car club activities, exhibitions, parades or other functions of public interest or for a private collection and is used only infrequently for other purposes; and (b) has a collectible vehicle or classic automobile insurance coverage that restricts the collectible vehicle mileage or use, or both, and requires the owner to have another vehicle for personal use.

Just call up your insurance company and get quotes for classic car insurance and you can remove your entire emissions system to include the catThis insurance is available but it is NOT easy to get.The state did not pass this law so anyone with a 15 year old car can skip emissions check.You have to provide pictures and all reciets to prove vehicle is completly restored.You also have to prove that it is stored in a locked garage.You must not drive the vehicle over 2000 miles a year and you should be a member of a collecters club.

[dbozman]

Yes, I'll get a manual. Unfortunately I'll have to order it and wait for it to get here, which doesn't offer me much help on my current problem I'd like to solve.

Before we get sidetracked on insurance, does anyone have any concrete technical knowledge on this issue? I'm not talking about removing the canister underhood. I'd like to do away with all the dryrotted junk that came out from under the DS fenderwell (rollover valve and the other piece).

Thanks.
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[idontknow]

on my 78 cj7 the previous owner removed all the air system stuff so i have 2 lines running together that go from tank to carb. one is a fuel feed line that goes from tank to pump to filter to carb the other is a return that goes from the second port on my fuel filter to the tank.those are hard fittings on my tank.

but then i also have two lines(smaller)that come off my tank and go to the liquid check valve under my left tail light. thats all i have run with it.

p.s.if you have fluid in your tank the port that makes a bubbling noise when you blow on it is probably the feed port.if that makes any sense