Fuel tank vent

[Mach1Fastback87]

There is a little tube in my engine bay that I suspect goes back to the fuel tank. Is that something I can remove and plug or is it needed. 84 5.0 carb with no erg or smog. Thanks

[JACook]

Do yourself a favor and put the evaporative system back. It will eliminate the inside of your car
(and your garage if you park in one) smelling like gasoline. Evaporative emissions systems do not
cost even a fraction of one horsepower, and if you're the least bit creative, the whole works can be
hidden where none of your friends will know it's there. I wouldn't be surprised if the bracket (or
even the canister) is still up under the passenger side fender.

If you just remove or cap the vapor line, your fuel tank will build pressure.

[kingstang]

^What JACook said.............

[Mach1Fastback87]

Im not sure what you are talking about. with the evaporative system but i have had the finders off and there isnt anything behind them. the Po took the cruise out of the drive finder. Im working with something someone has already messed with.

[Mach1Fastback87]

does it hook up to the charcol filter? I still have the charcoal filters they were in the truck when i got the car.

[mustangxtreme]

Yes and there should be a vacuum line and solenoid that runs to the carburetor float bowl vent.

[Mach1Fastback87]

Oh no I don't have any of that. My whole wiring has been cut and messed with. It has only the wires required to run, no a/c or any thing. I guess I'll have to figure something else out. No wonder it smelled so bad when I got it, that line was open and the fuel bowl vents was open.

[boboli]

I would hook the system back up. You can have all sorts of issues like a pressurized fuel tank, that can be difficult on a fuel pump( usually on fuel injection with return), gasoline smell in your engine bay and garage that can be slightly annoying to overwhelming. In an extreme case , not seen or heard of by me on Ford's, the absence of a proper fuel tank vent on older jaguars actually causes them to expand until they rupture. Got to love British engineering!
The system uses no horsepower and is somewhat beneficial to a car.

[Mach1Fastback87]

I wish I could hook it all back up but like I said There is no wiring in place anymore and I dont have the solenoids, but I do have the charcoal filters. I dont think that does me much good.

[JACook]

You don't need any wiring if you're just hooking up the evaporative system to the fuel tank. And if you
no longer have the stock carburetor, that's your only choice anyway. The only electrical connections on
the original system were for the carburetor bowl vent solenoids. Otherwise, the entire system runs off
vacuum.

Apart from the lines that went to the stock fuel bowls, the system needs only to connect to the fuel tank
vent line, and also a pair of vacuum lines for canister purge. One goes from the purge valve to manifold
vacuum, and the other is a control line that originally went to EGR vacuum, but can work just as well off
the ported vacuum source for the distributor.

This thread should have all the info you need to get a canister purge system working-
http://vb.foureyedpride.com/showthread.php?t=71264

And this post in that same thread has the Cliff's Notes photo of what the purge valve looks like, and
what needs to connect where- http://vb.foureyedpride.com/showpost...4&postcount=37

Your car originally would have had a much more complicated evaporative system than you probably need
now. Originally it would have had one canister on the engine bay side of the right frame rail, and a second
canister on the fender side. I don't have a good photo of the mounting bracket, but if you look at the back
side of a canister, you'll see the wedge shaped area that engages the bracket, so you know what to look for.

[rapidroy]

I am not sure of what smell thay are speaking of but i have had my whole system removed even egr set up and have never had any bad gas smell. That hose he speaks of i just let vent into engine compartment, been that way for years.

[JACook]

If you don't ever smell fuel in your car or in your garage, I would suspect your vent line is blocked. Does
your fuel cap ever hiss when you remove it? Otherwise, perhaps the smell just doesn't bother you, which
is fine, but you might want to check with any people of the female persuasion that ride in your car...

[cb84capri]

it smells like walking into a cloud of stale gasoline. that's what it used to smell like prior to rigging up the evap stuff. .

cale

[rapidroy]

No smell what so ever and i hate gas smell and no pressure on my gas tank. Also have had no one say anything to me about any smell. My right window won't go down in hot weather still not even a trace of gas smell and gas smell make me super sick. It an 86 fuel injected if that matters. No smell under hood at anytime. Sorry guess i just got lucky.

[Mach1Fastback87]

mine smelled so bad when i got it. I guess thats why it did smell. the fuel bowl vents were open and that hose was floping around. JACook thanks for the post Ill have to look into those items. As all i have is the filters I will have to figure something out I guess. But hey its a start i guess.

[Mgino757]

I think I want to get my evap system up and running. I have the hard line coming from the fuel tank in the engine bay and I have one charcoal cannister in the engine bay, that's it. My secondary fuel bowl is not the vented type, as the original is no longer available. The vent from the primary fuel bowl is currently capped. When ever I go to refuel, I sometimes get hissing from the pressure build up in the gas tank when I unscrew the fuel filler cap. What I want to accomplish is set up the evap system so it manages the fuel vapors from the carb and the fuel tank so there isn't any build up. For those who don't know, this is on my 85 Mustang GT. What's the best way to hook it up with that I have? The cannister has the mushroom cap, I assume it's a vent, on one side and the other side has nothing in the hole.

[81coupe]

My plastic vent line is laying open on the fender since Engine swap. I've never smelled anything yet or had any complaints so far. Even stored in a Garage. I have one Canister in place, but not hooked up though. But like others have said, I have had no problems with the Gas tank being pressurized either.

[xctasy]

You'll need this (which you can get new or used, and its either black or whilte) They go under the passenger side fender. There is a second for V8's (mine was an I6)





Extra details on it are in these three posts.

http://vb.foureyedpride.com/showthre...vap-components
http://vb.foureyedpride.com/showthre...rcoal-canister
http://vb.foureyedpride.com/showthre...rcoal-Canister

In my June 2012 ITZ OLD Stang VIN and HEAD 125___06 v1 file is a bunch of pictures


6438-6642.









In my opinion, the rear float bowel vent doesn't have to work as long as the front one does. There may be some operational issues, but they are liely to be minor if you just hook the Evaporative emissions up to the front bowl. I'd personally fit EGR up, as that helps fuel economy, and makes the engine run cooler.

There are other side hanger float bowls with vents...only the Ford OEM ones for the 4180/4190 and 2300 carbs (truck based and gvw of 8 plus tons) had electric solenoids...the Holley list replacements for smog legal trucks and passenger cars from 1973 to 1979 had a plastic vent pin, with a rod operated bowl vent.

1967 on AMC's with the 1931 Holey 1-bbl,



67-68 Autolites had there own closed float bowl system, Holley copied it at Fords behest with Six pack 340 and 440 carbs (which were orginally designed for Fords Cleveland 366 NASCAR engine, so its a Ford part)








The last one is the stand in List 80451; 4160 600 CFM. Of couse, its incorrectly hooked up in the picture, but the front float bowl is the only vented part.

#37-1536 carb kit

#622 primary jet

#39 secondary plate

#31 squirter

#125-208 2-stage PV (1st Stage Opening 10.5" Hg; 2nd Stage Opening 5.5" Hg.)


I don't think a few minor matters like a non stock, non 4180C rear float bowl will stop you benefiting from the Evap system.

[Mgino757]

I think my primary goal is to relieve the pressure build up in the fuel tank and any vapors from the primary bowl. I just ordered a purge valve, as mine are nowhere to be found. The only thing I'll need to sort out is the necessary hookup to the charcoal canister, that is long gone too. Is there anything else that I would need to get this stuff working?

Oh, and EGR isn't happening. I tried that route, there's too much stuff missing to get it properly working again.

[Mgino757]

Okay, so how's this for an idea?

I hookup EGR vacuum feed on carb to top port of purge valve, hook up manifold vacuum source to bottom port, hook up middle port to canister with fuel tank and fuel bowl tee'd in. Maybe tie in the TAB and TAD solenoids? I currently have both thermactor air diverter valves on manifold vacuum to have fresh air pumped to catalysts. Any input would be great. Help! Mr. Cook? lol

[JACook]

So nothing about the purge system should have anything to do with pressure build-up in the tank, so you
need to figure out where the blockage is. I had this same problem on my '85 Hatch, even with all the evap
stuff still in place. Finally got around to figuring out why, and found the evaporative hose to the to of the
tank had gotten between the tank and trunk pan. It was permanently squished shut.

The connections for the tank and bowl(s) can be done with a single canister. Did that on my old '78 wagon
when I put the '85 engine in it, back around 1988 or '89. If you have two bowls to vent, you just have to
make sure you use two vent solenoids before the Y. If you only have one bowl vent, you obviously only
need one vent solenoid. Everything still ties together like in the thread I linked above in post #10.

To those who don't have any problems with fuel smell, I'm happy for ya, but obviously your experience is
not shared by all of us. Important concept there...

[Mgino757]

For what it's worth, I currently have the vapor line from the tank capped.

[Mgino757]

I just uncapped the vent line. I'm thinking of running it to the middle port of the purge valve, bottom port of purge valve to fuel bowl vent, and top port to ported vacuum, maybe I should run this to EGR port on the carb instead? I need to find the F-fitting for the canister or fab something up with various vacuum fittings and hoses. I also verified that the vent tube was not clogged. I was able to move air through it with very little effort.

As for the thermactor system, I have manifold vacuum connected to the bottom port of the TAB solenoid and the vacuum hose from the upper connection on the TAB solenoid to the air bypass valve. For the TAD solenoid, I have EGR vacuum on the top port and a vacuum hose on the bottom port going to the air diverter valve. Thoughts?

[JACook]

For what it's worth, I currently have the vapor line from the tank capped.

That explains the pressure in the tank then.

The only part of the purge system that should go to EGR vacuum is the control port on the purge valve.
The purge flow needs to connect to the intake manifold. Originally, this would have gone to a nipple on
the front of the EGR spacer.

[Mgino757]

Out of curiosity, wouldn't that create a vacuum in the fuel tank/fuel system? Would that put extra work on the fuel pump?

I'm also confused on how I should hook up the charcoal canister.

EDIT: I think I got the charcoal canister figured out. So I guess I'll connect the fuel tank vent hose to one side the canister. Put the middle purge valve port on the same side of the canister, and lower port to manifold vacuum. I think I'll also forgo the fuel bowl to charcoal canister connection until I can find the correct vent solenoid, this way I won't be messing with the pressure in the fuel bowl.