Filler neck 2nd nub routing

Garrett

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Hi all,

I've searched the archives and found multiple references to the nipple on the fuel filler neck that routes to the plastic expansion tank, but few if any references to the 2nd nipple on my fuel filler neck, which is presently connected to a fuel line and has a stopper in it.

What is the purpose and correct routing/connection for this nipple? The realoem schematic shows it connecting to fuel line and then to a grommet, but what then?

My configuration is a 3.5L injected conversion with the stock CS tank and in-tank pump conversion. Appreciate any guidance on this.

Thanks,
Garrett
 

bavbob

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On my Euro 3.0 cs, the line is a fuel line that actually ran below the right rear light and then vented out below the rear cowl. On my Bavaria, the expansion tank runs to the charcoal filter under the battery and from there, to the air-filter housing. This was part of the Thermo-Exhaust/EGR-like set up for American cars. Not sure if this is helpful but these were the filler neck options back then.
 

Garrett

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On my Euro 3.0 cs, the line is a fuel line that actually ran below the right rear light and then vented out below the rear cowl. On my Bavaria, the expansion tank runs to the charcoal filter under the battery and from there, to the air-filter housing. This was part of the Thermo-Exhaust/EGR-like set up for American cars. Not sure if this is helpful but these were the filler neck options back then.

The concern I have about using this line as a vent is that when I uncorked it and pressed on a full tank on level ground, the minor deflection in the tank caused raw gas to spill out of the line. And isn't the purpose of the 1st line going to the expansion tank to handle the thermo pressure, so not obvious to me at least why I need another vent line?
 

aearch

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really not necessary as its for smog only
venting back
i have deleted my charcoal canister and put cruise control there.
 

bavbob

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One line rises to expansion tank (vents tank with fumes to canister and then allegedly burned at carburetor so no, not for pressure.), other line drops outside below bumper (overflow).
 

HB Chris

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Where are you located? I think there should only be one nipple, US coupes had the expansion tank, euro coupes vented under the trunk. When filling my tank, I stop after it shuts off twice, you don't want fuel in the neck. Also, the cap is not vented (ohne luftung) so the vent line is needed. Sounds like you may have over filled your tank.
 

Garrett

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i'm in California, car was originally a US coupe, but with two nipples. Possible I overfilled, as I recall in this instance I topped off just one click after the first shut off. I'll go with BavBob's recommendation and run the line out by the bumper. Thanks for the help.
 
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