First time I'm using the garage with the vette. It's smelling up the entire house! Can't figure out where the gasoline smell is coming from...I checked EVERY line and connection and nothing seems wet or out of place. There is no charcoal cannister (it was removed and the vent line plugged), and there is a brand new vented gas cap on there. When I slowly remove the gas cap, I hear hissing which leads me to believe there are no vapor leaks anywhere. Any thoughts or ideas are much appreciated!

 

Don't know. Last winter my Brother In Law said I coud use his garage and he complained about the gas smell. -which I 'could' smell. This year I left the car in my garage and..... no smell. Maybe my garage is not as tight as his ? I don't know.

 

Check for fuel boiling over after shutdown.Carb heat soaks and fuel will boil-over into the manifold.had this problem needed a heat shield ,thick carb gasket...good luck

 

Definitely not coming from the front of the car....car has aftermarket MassFlo fuel injection. I can smell the odor at the back of the car by the tank, but see nothing. The thing that's throwing me off is the hissing from the tank when I remove the new vented cap - if vapors were escaping on their own through a cracked hose or leak, the tank wouldn't be sealed enough to make the hissing when the cap is removed. I don't get it.

 

This is a dangerous situation with the car in the garage. Any spark in the area, such as from a light switch, could ignite the gas fumes. I'd get 'er fixed asap.

 

I had a leak from the bottom mounted sender fuel tank in my 68. It dripped onto the spare so nothing on the floor but a lot of smell.

 

This is a big clue.

 

I think Mike is indicating gas vapors are normally vented through the charcoal canister. By plugging the line you are not providing any means to relieve pressure in the system. So you could build say 20 psi in the system and it will force a small leak of vapors causing the smell but once it drops below the force necessary to leak it stops. Thus when you open the cap you will still get the hiss.

 

Kind of makes sense in a way. But what about lets say a 5 gallon jug of gasoline kept in the shed for the lawn mower. That's in a sealed container and doesn't leak vapors or smell until you open the cap, no?

 

I'm not sure about your year but my 69 has 2 soft lines that run from the fuel tank outlet fittings, high on the passenger side, to the hardlines that run forward along the frame rail. You have to get under the car with a good light and look up to the top corner of the tank to even see them. One is the fuel supply line and one is the vapor return line. I replaced mine 1-2 years ago due to the same problem you're having. It wasn't easy but it was do-able. Mine were clearly the original rubber lines from the factory and they were seeping fuel and vapor. It may not be exactly the same configuration on your year but it should be similar, possibly minus the vapor return line. It's worth a look.

 

What he said. Does the nipple on the tank for the fuel separator have a cap on it? Also, the seal for the sending unit may be bad.

 

It's a brand new Eckler's replacement tank for the '78. The sending unit/filler neck is new also. Because of the fuel injection, holes were tapped into each side of the tank (one for delivery at the bottom left, and one for return at the top right). The stock delivery/return tubes at the sender/filler are capped off. The vent tube from the sender/filler that goes to the charcoal canister has a short hose that goes to a vent fitting at the top of the tank to the left. From there, another hose is connected that was just an open vent to atmosphere. Thinking that was my problem, I capped that open vent hose. Still have the horrible gas odor....

 

Get a vented gas cap.

 

 

Don't need the vapor canister. It is useless. Simply block off the line with a vacuum plug and buy a vented gas cap at auto zone.

 

I have a brand new vented cap on there which is working fine (one way to let lost air INTO the tank)......

 

I agree,..in this case, it's not clear how air is allowed back into the tank to replace spent fuel.

But a vented fuel cap won't solve the 'fuel odor' problem. A vented cap (if working correctly) has a one-way check valve; it allows air into the fuel tank but won't allow fuel or fumes to escape for obvious reasons.

 

As stated, I HAVE a vented cap on there. Air has no problem getting in the tank when needed, but somehow the vapors are escaping and stinking up the garage despite the system appearing to be sealed and tight.....
Definitely scratching my noggin on this one....

 

I had the same problem you're having with fuel smell. This may or may not help you but it worked for me.

If you do not have charcoal canister or not using one like me, most likely fuel smell is coming from the fuel overflow valve line on the driver side of the gas tank. When you make hard turns or climbing hills, fuel will splash around in the tank and may spill fuel through the overflow valve. My original fuel line from this valve connected into a 90 degrees steel valve line that led to the charcoal canister. Green arrow is pointing to a 90 degrees valve where the fuel line from overflow valve originally connects to and where the other end of that line connects to your charcoal canister.


Buy 3/8" transmission or fuel line (about 6 feet minimum), few cheap fuel filters, clamps and do what I did if you wish. Yellow arrow is where I have my first fuel filter where it is position little upward for mininum over flow of the fuel if and when spills. I ran 2 feet of extra 3/8" fuel line and install a second fuel filter (red arrow) as backup. With only one fuel fliter (yellow arrow) I can see vapor coming out but with the extra 2 feet fuel line in loop and with an additional filter, I do not see any vapors or smell of fumes. I've had this setup for 3 months in my garage and no gas smells. Before this setup, I had terrible gas smell in the garage. Some in this forum may disagree with this setup but it works for me at least.

 

hmmmm, sounds interesting. What did you have on that line before the filters were put there? Was it just an "open hose to atmosphere" to enable venting out??