Having just did my rear gears, I noticed there is a vent line from the top of the gas tank that heads to the engine compartment. Can this be used as a fuel return from a regulator? If my motor has all the egr emissions pulled, where does it go? Should t be capped? Etc
Breather tube as a return line
- Thread starter swies
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67Dart273
Well-Known Member
you need to look this up in the factory shop manual. This has changed over the years, I don't know what might be different between 73-4-and 75
That IS your tank vent. You need to leave it open, or rework things.
If I had one of these cars I would weld a fitting into the filler neck just exactly like the 69 /earlier cars did.........This is an open vent, it originally is exactly as pictured........the lower end of the vent tube is open, and ends inside the rear frame rail. The reason it goes "up high" (Up against the inside top of the rear quarter) is to prevent siphoning. Only time that setup will siphon is if the tank is really full, and you are parked on a side-hill with the filler side downhill. Then, it will only siphon enough to get fuel below the vent line fitting in the neck
https://www.google.com/search?q=67d...1N6QI-&biw=1025&bih=460#imgrc=jcFlPdwVSUJ8qM:
That IS your tank vent. You need to leave it open, or rework things.
If I had one of these cars I would weld a fitting into the filler neck just exactly like the 69 /earlier cars did.........This is an open vent, it originally is exactly as pictured........the lower end of the vent tube is open, and ends inside the rear frame rail. The reason it goes "up high" (Up against the inside top of the rear quarter) is to prevent siphoning. Only time that setup will siphon is if the tank is really full, and you are parked on a side-hill with the filler side downhill. Then, it will only siphon enough to get fuel below the vent line fitting in the neck
https://www.google.com/search?q=67d...1N6QI-&biw=1025&bih=460#imgrc=jcFlPdwVSUJ8qM:
You can run it as a fuel return, but you need to run a vented gas cap if you do.
Lustle
Well-Known Member
Honestly mine just runs to the engine bay and is just open right there. Like someone cut the charcoal canister out and left it. Do I get gas fumes sometimes? Yes. Should I put a filter on it? Maybe. Have I not needed to use cologne all summer and only wear eau du premium? You betcha.
you need to look this up in the factory shop manual. This has changed over the years, I don't know what might be different between 73-4-and 75
That IS your tank vent. You need to leave it open, or rework things.
If I had one of these cars I would weld a fitting into the filler neck just exactly like the 69 /earlier cars did.........This is an open vent, it originally is exactly as pictured........the lower end of the vent tube is open, and ends inside the rear frame rail. The reason it goes "up high" (Up against the inside top of the rear quarter) is to prevent siphoning. Only time that setup will siphon is if the tank is really full, and you are parked on a side-hill with the filler side downhill. Then, it will only siphon enough to get fuel below the vent line fitting in the neck
https://www.google.com/search?q=67d...1N6QI-&biw=1025&bih=460#imgrc=jcFlPdwVSUJ8qM:
Damn your smart!! I wish you lived in Boise......
Down the street.....
Within car pushing distance....😜
A vapor return line doesn't end submersed or near bottom of tank. So...
To use a stock vapor return line is much like peeing. The fuel gets splashed, atomized to create more vapor, and loose some of its potency out the vapor vent.
To use a stock vapor return line is much like peeing. The fuel gets splashed, atomized to create more vapor, and loose some of its potency out the vapor vent.
nm9stheham
Well-Known Member
If you put the canister back in, then it will still need to be purged... which means putting the vapor control lines and controls back in the engine compartment. I have been trying to figure up a bad scene of fuel spillage with this being used as a return, but have not thought of one yet. I'd push some low pressure air back into this line with the cap off, and see if it comes out the filler; there were some funky purge line configurations and you want to see if there is a check valve anywhere, and if it will flow adequately. Then use a vented cap as RRR suggested.
That's what I use for a return, my 74 cap is vented.
KitCarlson
Well-Known Member
That line in my 66 is only about 1/4 OD. That would likely be too restrictive as a return. I did run a line from there to charcoal canister as part of evaporative emissions control, that works.
67Dart273
Well-Known Member
It is for a "great big" return regulator and or EFI. They are good enough for an orifice return like the factory used for vapor lock
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