Exhausting Gasoline Smell [HELP]

[5N4K3]

My carbureted Hotrod makes my attached garage and the part of my home closest to the garage smell of gasoline. I would like to put the garage under negative pressure so the fumes leave the garage and the house doesn’t smell. Any thoughts??
In the summer I leave a window fan (in exhaust mode) on, but I am looking for a more permanent solution that will work in the winter and summer rains.

 

[kbs2244]

First I would check the car out for fuel line leaks.
Even a carbureted car shouldn’t smell.

Then I would get a roof vent.
Maybe powered.
If you have a ceiling and attic try running a duct from the ceiling up through the attic to the vent.

 

[Stuart in MN]

Yes, look for leaks - there shouldn't be any smell.

 

[e-tek]

Have you checked the top-side of the tank....water and crud can rot that area out...

I have a humidistat on a window fan in the attached gaage - fan goes on when humidity increases....

 

[Gary S]

Every time I've had an old carbureted car that smelled of gasoline and there were no leaks, I replaced the fuel pump. Each time, that $15 fuel pump fixed the gas smell. When the membrane starts to break down inside a mechanical fuel pump, the fumes are vented into the air and the gas smell gets really bad in your garage.

 

[Need4Speed]

I have also experienced the fume issue on my track car but it usually goes away after a few days.

A couple thoughts on this.

1) Carbs have vents to the bowls that are open to the airfilter housing and on larger aftermarket carbs they seem to be more free flowing vents. A simple test would be to put a plastic trash bag over the carb/air cleaner housing and seal it off for a while (days?) to see if it helps. If you do this it would be good to put a reminder note on the dash so you don't forget its on there.

2) The tank could be vented to the atmosphere so you could seal that off and see if that helps. Once again put a reminder on the dash. If this fixes it you could put a small inline fuel filter on the vent line to see if that will help or another alternative is to put on a low breaking pressure one-way check valve.

3) If you have an aftermarket fuel tank/fuel cell they are notorious for emitting fumes, especially if it is made of plastic. Not much you can do other than relocate it to the trunk wher eit would be more sealed off.

 

[Falcon67]

#1 - where are you? If you are in an area with ethanol or other BS EPA bastardized fuel (like Houston, Dallas, - most non-attainment cities) you will get this problem worse than most places. Has nothing to do with fuel pumps or leaks - it's just the way it is. We had this problem big time in Houston and the fuel STINKS which makes it worse yet. That was probably MTBE down there. It is still a problem with regular fuel out here in the sticks - and it's mainly because EVERYTHING else since the late 70s has a more-or-less operative vapor containment system on it and we are not used to the stink anymore. If the evap equipment is even half-*** working the car won't stink much. The leftover Burger King under the back seat will overpower any fuel smell.

If don't have an electric fuel pump, get one. Toss the mechanical unit and wire up a cutoff switch in a hidden place like under the dash. When you bring the rod home, switch off the pump and run it at fast idle/partial throttle until it starts to stall then shut 'er down. (this is also a bitty security device for parked shows and cruises) Vent the garage with fans and that's about the best you can unless you put an air exchanger in the wall. I run out the race cars when I put them in the shop - if I don't, you go in there the next day and vent the place or pass out. And that's with tight fuel systems and steel lines - you still have front/rear carb vents and if its a race car/hot rod maybe a vented fuel cell. Another thought is to get a cheap 3000 lb electric winch from Harbor Freight, run out the car in the driveway, let it cool and use the winch to drag 'er into the shop. You can also try capping the carb vents between excursions.

That's my best advice - been there, deal with the issue every week because one hot rod or the other needs a visit to the shop after the races LOL. Doesn't bother the house because here the shop is detached, but if I don't run the carb out of the shop car I'll go out there for a couple of minutes later and come back in smelling like 93 Exxon. If I'm real energetic, I'll back the trailer up so that we can push the car off and roll it into the shop without starting in the first place. I always run the carbs down after loading the hot rods at the track. That's because if one carb DOES decide to spring a leak (base plate, metering block gasket, power valve, etc) I have less chance of a big bad surprise handed to me by a cylinder full of fuel.

 

[mikeyr]

When I first read this thread I assumed he was talking about exhaust smell as if he is running rich. There should be NO gasoline smell from a car, if it smells like gasoline, you have a leak somewhere.

Try this, (OK DONT TRY IT FOR REAL) get a old coffee can and fill it with gas, throw a lighted match in it, no boom, no fire. Now hover a few inches above that with the lit match and boom. Its the gas fumes that are explosive, FIX your car !!!

Its pretty simple, is the gas cap vented ? fuel tank leaking (often at the tank sending unit), fuel lines, fuel filters and finally the carbs.

 

[bgott]

What kind of engine? Carburator? The floats might be set high and the fuel is percolating down the throttle bores when you shut it down hot. How hard is it to start after you shut it down hot?

 

[back2class]

You have a mechanical problem, not a garage vent problem. Let me put it in simple terms, you can keep plastic gas cans in a grage with no cap on the nozzles or vents and it will not smell up your garage. You have wet fuel spreading over a surface then evaporating. My guess is bad carb float adjustment but you most def have a problem and a pretty good leak in the fuel delivery system or a big hole in the tank area.