Heavy fuel smell after sitting

[Scott R]

I did a search, but didn't net much. My issue is I have a heavy fuel smell in the garage after the car has been off and sitting for about 15 mins. This started sometime after the carb conversion, but I'm not sure why.

I have the PMO fuel block and the return is routed back to the tank and it works. I don't have any fuel on the ground and my mileage is pretty good considering my modifications.

Am I missing some sort of vent or breather somewhere that I need to cap off or route correctly?

[ossiblue]

I assume your car had a gas tank/emissions venting system with the charcoal canister, evaporator box, etc. The fumes eventually were routed via vacuum hose to the intake of the CIS. Did you reconnect all the emissions hoses?

[James Brown]

I see you have CARBURETORS, fuel in the floats are vented to atmosphere. Also, there is raw fuel in/around the ventures (not much, mostly vapor). This is what it does. Enjoy! Got a good fire extinguisher? Seriously, nothing to worry about just be aware that this is not like the FI was.
ossiblue, ahhemmm, carbs?

[Scott R]

Yes they are Weber 40's. I'm going to check for any missing emissions connections as per the above post, but I think I think I got them all. If this is how carbs smell, then, OK, I can live with it. I would not give the carbs up for anything at this point.

[ossiblue]

Originally Posted by James Brown

I see you have CARBURETORS, fuel in the floats are vented to atmosphere. Also, there is raw fuel in/around the ventures (not much, mostly vapor). This is what it does. Enjoy! Got a good fire extinguisher? Seriously, nothing to worry about just be aware that this is not like the FI was.
ossiblue, ahhemmm, carbs?

Oh, I understood the carbs. He had done a carb conversion from a system that had incorporated a vapor emissions system. I was asking if he reconnected the hoses that had been on the car.

[James Brown]

Oh OK where do you connect the hose to? just a vacuum port or tap into a manifold port? (ripped mine off but I SHOULD hook it up to be a good steward of the earth)

[ossiblue]

Originally Posted by James Brown

Oh OK where do you connect the hose to? just a vacuum port or tap into a manifold port? (ripped mine off but I SHOULD hook it up to be a good steward of the earth)

The line, actually a purge line, goes to the air cleaner--unmetered air. The fan pushes air through one line, through the charcoal cannister and out the purge line. The location where the line connects to the air cleaner is slightly different among the various years.

[James Brown]

yeah ok thanks. Anyway, think that might help Scott R?

[rfuerst911sc]

What air cleaner/cleaners are you using ? I think open K&N housings either billet or metal rainhats are going to let the smell out regardless of what you do. If using the OEM housing it is more of an enclosed assembly with a much better chance of keeping the smell contained. I have PMO's on my SC with rainhats with minimal fuel smell. I have Weber 40's on my 914 GT clone with K&N billet air cleaner assemblies and she has a considerble fuel smell after shut down. I'm thinking about going with the OEM filter housing to see if that helps. But either way carb's are old technology and have some quirks we don't see in modern EFI.

[Scott R]

I have the PMO open rain hats and the K&N's. I only have the oil tank line kit installed. The lines from the oil tank to the hats. Which I bet means that I have an open vacuum line to the canister that I still have.

I'll post some pics up in a pit.

[James Brown]

Any way you go I don't think that you will get rid of 100% of fuel smell from a carbed car.

[stlrj]

All engines now are fuel injected, so the gas companies are not making gas intended for carbs nor do they really care. They have been steadily raising the RVP's ( Reid Vapor Pressure ) for better emissions but in an unpressurized float chamber, the gas will just vaporize into thin air, unlike the old stuff we use to get.

[stlrj]

Originally Posted by Scott R

I did a search, but didn't net much. My issue is I have a heavy fuel smell in the garage after the car has been off and sitting for about 15 mins.

Is there a gas furnace or gas water heater in your garage too?

[777joee]

Originally Posted by James Brown

Any way you go I don't think that you will get rid of 100% of fuel smell from a carbed car.

Today's gas will vanish from the float bowls in about 4 days if that. It is VERY prone to evaporate more so than fuel in the past. With a 911 we are lucky because we all have electric fuel pumps so as soon as you hit the key you have filled the float bowls.

The poor guys running a 356 need a helper external pump. Another cool way to do it is put a outboard motor inline hand pump bulb where it can be reached to prime the float bowls or just crank it and hope the battery lasts........