Charcoal Canister Delete

[DVZ]

Have an '85 euro 3.2 carrera. Fuel vent system was added when car was imported. Charcoal canister rusted, broke apart and is not an original porsche part that I can replace.

Anyone know if there are any issues with removing the tank vent system (i.e., canister, valve, lines, etc...)? Will I need to plug the line going from fuel tank to canister, install a vented fuel cap, etc... Thanks in advance for all suggestions.

[RSBob]

Be prepared to have your garage potentially smell like gas. Not too much of a problem in the winter but when temps climb it can get pretty aromatic. Definitely not recommended if your garage is below your living area.

I removed all of the hardware associated with mine and after 3 years of smelling gas (unless you enjoy it with the added carcinogens) will be reinstalling this winter.

As far as your question goes, there should be no issues other than the above and many a fraction decrease in mpg.

[Slocs]

DVZ,

I had to do the reverse and install the system to get my UK import registered here in Australia.

Pre the install, my car simply had a pipe running from the evaporation chamber (inside the front left wing) to a vent right next to the fuel filler pipe. I simply removed the line to the vent, and replaced it with a new line from the evaporation chamber to the carbon canister, and then to the airbox

To remove your set up I'm guessing you need to:
- Remove the canister and associated line to the airbox
- Remove the line from the rear of the airbox body, and plug it with part number 930 110 256 00
- Remove the line from the evaporation chamber, and run a new line to the vent near the fuel filler (I'm hoping that all cars have this metal pipe already there)

My car never had a fuel smell.

Hope this helps,

Rob

[Slocs]

Here are a couple of images that may help.

The first is the scematic of the evaporation system. Tank 2 in the diagram is located next to the fuse box in the front trunk, tanks 4 is in the front left wing.

The second is a photo of the evaporation tank inside the wing. The fitting at the top is the fabric covered fuel hose that runs to the metal vent pipe next to the fuel filler.

Regards

Rob

[bavaria911]

I have a 1970 911 T, fresh from a engine rebuild and also 10 years of storage. I smell gas in the garage. Can someone please take detailed photos of their stock canister and hose fittings. Mine was removed 25 years ago and I recently purchased a VG charcol canister at Hearshey Swap meet.
Thanks in advance.

[RWebb]

the older ones are squarish - you can use the newer tanks as shown above if you are not going to concours the car

do a search on emissions and just bump the appropriate thread if there is something missing that you need

[DVZ]

Thanks Rob. The system I have in the car did not seem to have an evaporation chamber installed. In its place (on top of the washer tank) the charcoal canister was installed. Do you know what the evaporation chamber does?

I also have a vent valve ( 1980 Mercedes 450SL Vent Valve 123 470 03 93 ) installed in the line between the expansion tank and the charcoal canister. Not sure what that is for either.

[Slocs]

I understand that the basic premise is thus (however I work for a Bank so I could be totally wrong!):

- Fuel naturally expands and contracts under temperature changes
- The expansion tank (the clear one in the photo below) takes the overflow when fuel expands
- Vapours from this fuel are captured in the evaporation tank in the front wing, and ultimately are captured in the carbon canister (using 'activated' charcoal)
- The carbon canister has three fittings. The first is from the evaporation tank, the second is an air port, and the third goes to the intake system (just on the inside of the air box filter).
- When the engine is first started, or when accelerating away from rest, the small vacum that is formed draws the vapours from the carbon canister into the intake system and burns them up as part of the normal combustion process. The air port on the carbon canister is to allow the system to suck air through the canister (I think it has some sort of one way valve).

Given it's a closed system, no fumes can vent to the atmosphere, and thus there is no gas smell.

Hope that helps,

Rob

[kees]

Originally Posted by DVZ

Thanks Rob. The system I have in the car did not seem to have an evaporation chamber installed. In its place (on top of the washer tank) the charcoal canister was installed. Do you know what the evaporation chamber does?

I also have a vent valve ( 1980 Mercedes 450SL Vent Valve 123 470 03 93 ) installed in the line between the expansion tank and the charcoal canister. Not sure what that is for either.

I also have a euro 3.2 carrera. The original charcoal canister is located in the rear right wheel arch. On top of the washer tank (left front wheel arch) is the expansion chamber (see pic slocs).


Kees.

[cmcfaul]

I disconnected mine as the tank in fender cracked leading to big gas smells in the garage. I initally pluged the line leading to it but this created vacume in the gas tank. I installed a one man brake bleader thing in the line that comes fromm the gas tank. It lets air into the tank but not out. has worked flawlessly for several years and no gas smell.

Chris,
73 911 E

[70SWT]

cmcfaul - can you post a pic of your set-up? Thanks

[cmcfaul]

In the above photo from Slocs. #4 is the evaporator chamber in the driver side wheel well (behind the headlight bucket). Mine cracked like most do over time and is usually a source of the gas smell. I simply disconnected the evaporator chamber from the gas tank, put the one man brake bleed thing in that line so air can enter the tank but gas and fumes can't exit. Its a one way valve. Fits in the line no problem. Make sure you put it in facing the right direction as it can be a bear to get out. I even reconnected the line to the evaporator chamber with the one man brake bleed thing in there so it looks completely stock.
#3 in the pic is where the line connects to go through the car and into the wheel well (to the chamber). Between #3 and the tank is a perfect spot.

Very simple and no issues for many years.

Chris
73 911 E

[70SWT]

I was mainly curious about exactly what product you used - from which brake bleeder kit. Is there one that fits or looks best. I'll look at them next time I'm shopping car parts.

Originally Posted by cmcfaul

In the above photo from Slocs. #4 is the evaporator chamber in the driver side wheel well (behind the headlight bucket). Mine cracked like most do over time and is usually a source of the gas smell. I simply disconnected the evaporator chamber from the gas tank, put the one man brake bleed thing in that line so air can enter the tank but gas and fumes can't exit. Its a one way valve. Fits in the line no problem. Make sure you put it in facing the right direction as it can be a bear to get out. I even reconnected the line to the evaporator chamber with the one man brake bleed thing in there so it looks completely stock.
#3 in the pic is where the line connects to go through the car and into the wheel well (to the chamber). Between #3 and the tank is a perfect spot.

Very simple and no issues for many years.

Chris
73 911 E

[bavaria911]

Please...someone that has replaced/new hoses and has no smell,,, just take photos of the plumming and post it. Pictures are far better than words / telling one to read a factory wire diagram.

[cmcfaul]

I will try to post a better pic when I get home but all I did was stick this in the hose which eliminates the Evaporation Tank and charcoal canister completely. It's a "one man brake bleeder". Cost $2.50 and lets air into the tank as fuel is burned off but will not let fuel or vapors out.


Chris
73 911 E

[bkreigsr]

baveria911
The older ones are not 'squarish' but cylindrical, and you can't use the newer plastic one and still install it in the proper location.
Bill K

[bavaria911]

Bill,
That is the same one I bought at Hershey Swap Meet in Apr 2011.
Just have no idea how the hoses connect in and around the boot area. A photo always helps me.

Can you provide various pic's of how the hose network is in the car?

[bavaria911]

Bill,
That is the same one I bought at Hershey Swap Meet in Apr 2011.
Just have no idea how the hoses connect in and around the boot area. A photo always helps me.

Can you provide various pic's of how the hose network is in the car?

[DVZ]

STflared72T, I have this valve installed in my car: Vent Valve Part #123 470 03 93 (not a Porsche part) It is a one way valve. You can Google the part number for a place to purchase it online.

The Charcoal Canister was completely rusted and I am guessing this valve was installed to eliminate the smell of gas. It was installed in the line between the Charcoal Canister and the tank vent line.

[bkreigsr]

there's a couple of good vacuum diagrams for the older cars floating around the forum that you should be able to follow. I don't think a picture would help you that much.
pretty sure one of the braided hoses goes throught the center tunnel, or by the heat duct in the rocker panel sill, then to a connection on the air filter to draw the vacuum. the other larger one goes to the expansion tank in the left front wheel well. I think the small one goes to the filler neck somewhere.
Bill K