Gas smell after driving

[34ford]

When I take the coupe,34 Ford, out for a drive and come home and park it in the garage and come out later in the day or in the morning I have a strong gas smell in the garage (not exhaust), gasoline. It usually takes 2-3 days for the smell not to be there. I run a fan to clear out the smell and it is back in the morning. I have tried plugging the vent on the gas tank when I park it. Turn off the switch on the electric fuel pump and let it run before shutting it down so there is no pressure in the line.  Thought it was a carburetor problem and changed it and still have the same smell. Small block Chevy with a Edelbrock 600, the one before was a Edelbrock 750. Can't find any leaks. Always smells like it's coming from the engine compartment.  
 
Anybody have this problem or a solution.  
 
Thanks  
 
Bob

[Rayvyn]

When I take the coupe,34 Ford, out for a drive and come home and park it in the garage and come out later in the day or in the morning I have a strong gas smell in the garage (not exhaust), gasoline. It usually takes 2-3 days for the smell not to be there. I run a fan to clear out the smell and it is back in the morning. I have tried plugging the vent on the gas tank when I park it. Turn off the switch on the electric fuel pump and let it run before shutting it down so there is no pressure in the line.  Thought it was a carburetor problem and changed it and still have the same smell. Small block Chevy with a Edelbrock 600, the one before was a Edelbrock 750. Can't find any leaks. Always smells like it's coming from the engine compartment.  
 
Anybody have this problem or a solution.  
 
Thanks  
 
Bob

My figuring tells me that any vapors near a hot motor would be dissipated by the heat. That only leaves a fabric of some kind to retain the smell. It might sound simple, but can the air cleaner be the culprit?

[34ford]

Could be. It has an open element. What might cause the odor if it's not wet??
I would think the air being pulled in by the motor would not let it get wet.  

Here's what I'm  using as a air cleaner.

bob

[Bruce Dorsi]

I have noticed that today's gasolines have a much stronger smell than years past.  .....The amount of ethanol seems to have an effect also on the evaporation rate, as well as the odor.  

I used to store gas for my mowers in my garage, but the smell is now so obnoxious that the gas is now stored outdoors!

My buddy has a similar problem to you, and he believes the gas in the carb bowls is evaporating when the cars are parked.  

His rod with an electric pump quickly refills the bowls, so starting is not a problem.  ....His other car with a mechanical pump takes quite a while to refill the carb bowl, and starting is slow.  .....His garage also stinks after the cars are parked!

[enjenjo]

I agree with Bruce, particularly with an Edelbrock carb.

[34ford]

Thanks for the replys.  Probably the hot engine is causing the gas in the bowls to evaporate. I turn off the fuel pump when I start backing up the drive into the garage thinking that it will use the fuel out of the bowls. I have noticed when the car has set for a couple of weeks and I went to change the carb jetting and took the top off the bowls were dry. So that might be the problem. Might try putting a plastic bag over the air cleaner next time after I park it and see if the smell is less.  Will put a "Remove Before Flight" tag on the bag.


bob

[IC2]

I bought some middle grade Hess Gasoline for the first fire of my project car. That stuff is so rank smelling I find it hard to believe it will even burn. I almost smells like crude oil or asphalt. The odor came from the vent tube I found after crawling around underneath trying to find a leak. There was no leak but the stink from that tube about made me sick. I put a fan in the garage to keep the worst of it cleared out and put a cut off nitrile glove finger over the vent - and the odor went away. I also have an E'brock carb, but the odor from there was minimal. No more Hess Gas in that car (I also topped my truck off with about 5 gallons of that crap gas and the exhaust really stunk)

[Mikej]

I had the same problem with the 750 edelbrock. Try a carb spacer. Or switch to a holley like I did. Glad to hear your driving it, Bob.

[Dennis the Menace]

I have the same problem with our 56 Chevy we are also running a small block Chevy with an Edelbrock Carb & Intake with a K&N Air Filter.
Dennis

[34ford]

Glad to know I'm not the only one with this problem. I did plugged the vent tube from the gas tank to see if that would help last time and didn't make to much difference. I have a charcoal canister off of a car that I plan on putting in the rear by the gas tank like my last car but just haven't done that yet.

thanks all for the info

[C9]

I had the same problem with my 32.

Even with the vent tube run up as high as it would go in the trunk, there was a smell of gas in the garage.

Found a nice, small charcoal cannister, steel body, under the hood of a Toyota.
Front left side.

Ran the vent line into the cannister, then went forward about 3', installed an Earl's stainless screen fuel filter as a flashback arrestor similar to what's used in Oxy-Acetylene torch lines on the Acetylene side.

From there the vent line goes into the air filter in the filtered area.

Running that way for about 14 years, had a few backfires on startup, no problems and best of all, no gasoline smell.

[papastoyss]

Glad to know I'm not the only one with this problem. I did plugged the vent tube from the gas tank to see if that would help last time and didn't make to much difference. I have a charcoal canister off of a car that I plan on putting in the rear by the gas tank like my last car but just haven't done that yet.

thanks all for the info

I had the same problem, much better after I installed a 1" phenolic spacer under the carb. The Eldebrock carb has the fuel much closer to the engine heat than Holley ,so it is much more susceptible to heat soak , esp with alcohol blended fuel.

[midnight sun]

Over the past few years I have received two different replies from Edelbrock.  I Have a 600 cfm with performer intake.

One answer was:  

Gassy garage smell means the idle circuit is not tuned correctly.  Turn the mixture screws in a quarter of a turn and see if it goes away but still idles correctly.

The other matches pretty much what has already been said:


You're right; the problem is definitely a heat soak issue. Remember, the
fuel these days isn't too great and will evaporate at the drop of a hat.
Once the engine gets up to operating temperature and is turned off, the
carburetor will heat up and the fuel will begin to boil. It most likely
bubbles out of the boosters and drips down into the intake manifold. The
best solution is to install either a heat insulating gasket, one that not
only separates the carb from the manifold, but also shields the bottom of
the carburetor as well. You can get one from your local parts store or we
sell one, part number 9266. You can also use one of our Phenolic 4-hole
insulators. It provides the best insulation out of the two. Of course, you
can get an insulator anywhere, but ours is part number 8711 should you
decide to purchase ours.

My 2 cents

[34ford]

I do have the Edelbrock  Phenolic spacer. I tried something this weekend when I backed the car in . Turned off the electric fuel pump before backing up the drive and once in the garage reved up the engine to a high rpm a couple of times to clear out more of the gas and maybe clean out any possible gas in the exhaust. No gassy smell this time. Sometimes it's a hit and miss as far as the smell.

[C9]

"Even with the vent tube run up as high as it would go in the trunk, there was a smell of gas in the garage."


A little clarification about vent line location from my above post.

It looks like I'm venting the tank into the trunk, but I'm not.

After the line goes up high in the trunk - just under the sail panel* skin in fact - it goes back down, out of the trunk and was even with the bottom of the frame rail.

The gasoline smell was very strong there.


The small charcoal cannister is mounted under the body in back of the battery using the under-body battery's rear frame mounts.

Hope that helps.

*Sail panel - the sheet metal piece between cockpit rail and front of the trunklid.
Where the 3rd taillight mounts most times.