fuel line venting

[richmiller]

Hello, wanted to see if anyone has encountered an issue I'm trying to address. My car is a '69 911E and fuel vapors in the vent hose are accumulating enough to collect as liquid (fuel) that's dripping out the vent hose behind the front bumper and onto my garage floor. (At least that's what I think is causing fuel to be dripping out that vent hose.) It's not a lot of fuel mind you, but enough to create a fuel odor in the garage which isn't going over well with my wife. Plus, anything not right with fuel is, well, not right.

This is only my second 911 and first of this age so I'm eager for any advice/clues/ideas from those of you more experienced with older 911s. (My mechanic and others he's talked with are stumped as well.)

Cheers,
Rich

[SWS911]

Where behind the front bumper? You SHOULD have a charcoal canister in the front next the the battery on the drivers side. I would look at that, if it's still there, and the hoses that go to it.

[30westrob]

I went through similar issues with my 73 Targa. I used the pet to systematically go through every component of the fuel vent system and replaced all hoses and checked all components. A simple inexpensive system to refurbish. No more fuel smell.

Your system is over 50 years old and may greatly benefit from a refurbishment. Rob

[richmiller]

Originally Posted by SWS911

Where behind the front bumper? You SHOULD have a charcoal canister in the front next the the battery on the drivers side. I would look at that, if it's still there, and the hoses that go to it.

Interesting, I was told that the charcoal canister was not originally on my '69 so there isn't one there. Perhaps it was mistakenly removed by the previous owner. My mechanic and I were talking about adding that (not thinking it was original spec) as a solution. We'll give that a shot. Thanks!!

[richmiller]

Originally Posted by 30westrob

I went through similar issues with my 73 Targa. I used the pet to systematically go through every component of the fuel vent system and replaced all hoses and checked all components. A simple inexpensive system to refurbish. No more fuel smell.

Your system is over 50 years old and may greatly benefit from a refurbishment. Rob

We've done a fair amount of refurbishing on most of the car's systems, this included. I think the missing charcoal canister is the culprit.

Really appreciate your reply, thanks!

[HarryD]

This post from Grady clay, shows how the 1969 system is routed. Be sure the lines are clear. The little box (part 42), needs to be present and high up under the cowl on the left hand side.

Originally Posted by Grady Clay

Here is the 1969 Evaporative Emissions System


© 1969 Dr. Ing. h.c. F. Porsche K.G.
This shows the fuel system for the 911T (pump at rear), #2, 4, 16, 17.
and
the fuel system for MFI 911E & 911S, #3, 4, 7-10, 16-19, 37-42 and more.
(In 1970, the 911T is plumbed as the 911E&S here.)





The ‘tee’ fitting (#44 above) does not show a 3rd connection here.
My recollection is that is the small vent hose to the filler neck.

The outlet goes through a grommet (#47) in the front panel behind the windshield washer reservoir.
It vents between the front bumper and the inner panel.





System for '70-'71.

© 1970 Dr. Ing. h.c. F. Porsche K.G.


Best,
Grady

Part #1 in this picture, is where the vent box needs to be. You do not have parts 2, 3, 4, 5 or 6. Is this box present?

[richmiller]

Originally Posted by HarryD

This post from Grady clay, shows how the 1969 system is routed. Be sure the lines are clear. The little box (part 42), needs to be present and high up under the cowl on the left hand side.



Part #1 in this picture, is where the vent box needs to be. You do not have parts 2, 3, 4, 5 or 6. Is this box present?

Thanks for all this, Harry! (My apologies for the delay in replying.) This is really helpful!