I started to take the gas tank off my 77 Comet & noticed that vapor line that we have been talking about from time. I looked under the hood to see the container I have read about & there is nothing there. Under the hood hinge is a small bracket & nothing else. With a mustang tank, do I need that container? Can I run that vapor line some where else? I have no idea where the line on the old tank goes. I will have to chase that line once I get the whole car in the air.
Someone obviosly removed the canister and just left the hose hanging somewhere. You may have to leave the hose connected with the new tank for venting.......just make sure the end if it is higher than the tank. Someone will be along shortly to clarify.
Vapors have to vent somewhere. Before 71 they were vented out of the gas cap. 71 and up vent out of a valve in the top of the tank, through a line, up to the carbon canister, and on to the carb. You can easily get another carbon canister off another car and connect it the way it originally was. If you convert to a Mustang tank, you will need to add the vapor valve in the top of the tank. BUT...... I suppose you could drill a hole in your gas cap somewhere or put a notch in the rubber gasket on the backside of the cap so that vapors could vent out the cap. I'm guessing that would work ok. If so, you would not need to add the vapor line to the front.
Dennis, What did you do about venting on the Mustang tank conversion? I saw a complete tank, install kit, sending unit, with drain plug for about $110. I don't want to lose my current gas cap. All my carbon equipment is in place. Seth
Is it possible to put a mustang gas cap on the car in the same location as the original cap? Would the caps be the same size? If I put a vapor value on the top of the mustang tank, the tank will be right up against the trunk, will there be room for that? When I look at it, it looks like there might be a small space. I see plenty of gas caps but I can't tell if they are vented or not. I just called Mustang Unlimited, they have gas caps that are vented. So can i just put a vented gas cap on the back & don't worry about the vapor line?
Most early Mustang caps will fit. I don't know about adding a vented cap withoug capping off the line designed to go to the charcoal cannister. I suppose that it could just be plugged and a vented cap can be added. I do know that even with the carbon stuff hooked up, my stock fuel pump pulls a vacuum on the tank. It sucks big time when I pull in to get gas. It must not be pulling air from anywhere other than the charcoal cannister, so I assume that is the only vent. Seth
I have seen vented caps with gas tanks like the Mav that fill in the rear leaking when full and accelerating but I guess it could've been a bad cap.
My article tells you how to make a Mustang tank vent like the 71-77 Maverick does. Parts are still available from Ford. Instructions are in this article I wrote. http://maverick.to/gtu_faq.php
Last one, I must be slow at this. Since I don't have a container, do I have to have one? Is there something else I can do with the line? Its not connected to anything now & I have not had any problems for the few years that I have had it. Some one altered it & so far it works. I really dodn't want that container.
The problem is your venting gas fumes out of the end of the line, where ever it ends. Maybe you will never have a problem. Then again maybe a spark in the wrong place will turn your car into a bonfire. Hard to say. Its better to put on a vented cap and plug the line if you dont want to use the carbon canister. Then again, it robs no power from your motor so I found it easier to just leave it there.
Okay I got it, thanks for the picture also because I sure didn't know what it looked like. I found out that YearOne has some containers that got to mustangs so I will take your advice. Thanks for being patient with me. I still have a lot to learn.
I found out were that vapor line goes, someome hooked it directly to the cover that hold the air filter in place. Is this safe?
It used to go into the carb anyway... I took my tank off and cleaned the rust out and epoxy coated it, then put it back on. The nipple at the top where the hose went on was rusted completely closed. I put 80 psi air hose on it and nothing went through. So, I plugged it and put it back on, and removed the hose, canister, everything. I never did anything to vent my tank, either. Maybe that is why I started this thread http://mmb.maverick.to/showthread.php?t=19462 now that I think about it. But, I have never heard or felt any "whoosh" when opening my gas cap, so I just assumed that it was old enough that the seals had weakened allowing it to vent.
While I have never heard or read of any gas tank explosions, Personally I would not run the vent line directly into the air cleaner housing. If the carb ever backfires, I dont think I would want a direct line, full of gas fumes, to the gas tank. I dont know what the carbon canister does exactally, but I would guess as cheap as the auto manufacturers are, they would not have put it there if they didnt have to. JMO
Now that I read this, it makes good since. I'm going to go with a 70 mustang tank. I think I will have to drill a hole and vent the tank though. I think this should work for what I'm doing with the car. THANKS
