I recently purchased a 84 corvette, don't know mutch about it. Someone had changed it to a carb. system. The car had been setting, I drained the fuel and put in some Amoco high test, when I did this I filled the tank to the top. I am not sure the my guage is working right though. I noticed that after driving it fo a while I had a smell of gas coming from the rear of the car after letting it set for a while. Can someone tell me something about this. I did notice that when I released pressure from the cap the smell went away. :confused:

 

Maybe your EVAP emission canister is full (if an 84 has one)... I'm not 100% sure though. Maybe someone else will chime in.

 

:iagree:

 

Frist welcome to CF.... check the canister, around the carb and look for drips down the fuel lines.... :thumbs:

 

vinnies87:

Not sure where the canister is around the carb. My fuel line passes through a see through filter and maybe one under the passenger side. It looks like there is some type of fuel filter behing the license plate but not sure. I don't see any gas leaks. :smash:

 

If you say its coming from the rear of the car you might want to pull
the fuel tank basin and take a look at the physical condition of the lines
back there. Also check to see if it appears gas has been getting past
the filler neck/fulel pump assy. I had a similar issue and replacing the
tank gasket fixed it...


[Modified by Unriced, 11:42 AM 2/3/2004]

 

The charcoal cannister should be up in the front bumper under the drivers side headlight motor.If the line from the tank is blocked or clogged,excess fumes will build up in the tank.Theres also a few rubber hoses in back of the car for the vent line and when they break with age,they can release a gas smell.I found that problem on my car.Im unsure what all the mods were done on your car but without a working vapor recovery system,the fumes have no where to go over time.

You may also have a emissions gap cap on there or a non vented one.
Sometimes switching to a vented cap will help the vapors escape the tank but im unsure if the gas smell would still be there or not.You can try that too.
Most older carb cars had a vented gas cap years back.

Also check to see if the cannister up front has been plugged off.There should be a rubber line coming from there that goes to the engine/pcv line someplace to help siphon off the vapors back to the engine.Some people do mods and dont hook that stuff up anymore.

If it helps any,my 86 had a total failure of the cannister system.I had to get a new charcoal cannister from GM and I installed a new metal line from the tank to the cannister and new rubber hoses in the back.They were all rusted clogged and the vapors built up so high in my tank,the tank became very very hot and was almost boiling the gas back there.On a warm summer day,I touched the gas tank under the car and I had to pull my hand off from getting burned.

When I took the gas cap off it Hissed and whooshed real loud for a long time.Im really lucky it didnt explode or catch fire or something..Once I fixed it,its stayed cool and everythings good now.WHew!

:cheers:

 

I will try a vented gas cap. I don't think that the fuel line goes through the canister just streight from the tank through the fuel filters, looks likr three of them for some reason. I am trying to get some time to work on this before I do any serious driving. It is killing me to look at it and not drive, but want to be safe and not sorry.. I will let you guys know what I find out. Thanks for the suggestions.

jim

 

Jim,
Im sorry if my post was misleading,I never intended to make someone think the fuel line ran through the cannister.The fuel lines run from the tank and under the passenger side floor area through the filter then the engine.

The vapor line from the tank to the cannister run from the tank and under the drivers side floor area.That vapor line got clogged on my car and the rubber hoses that connected them broke apart.That was the problem on mine and what I had to replace.
Hope this clears some of that up.
:)

 

Flip open the gas filler lid and remove the four torx screws and check the lines for breaks (moving them helps) and gasket condition. Since you said you filled it all the way up, maybe it leaks when filled to the brim. Check filler tube gasket for moisture.

Spread flour around the area with cap on of course, and then drive around a few miles swerving like mad. Get home and check for a wet spot. :D If you eliminate a possible leak issue, then you can at least drive it.

Undo vent line, attach compressed air and check it at the opposite end in engine bay at cannister assy.

 

I did find the canister up front by the driver side headlight. After tracing the lines from the canister I found that the rubber hose was cut. I did not trace from that point back to the tank. I will have to rack the car and trace out the line. Thanks. For now I will release pressure from the cap until I get this checked out.