Hey all!
I've been wandering the forums for a while, seeking tips and such, but now have found a problem I hope someone has some advice about. I've a '78 base L48. Almost bone stock, aside from the Edelbrock 2101 intake and 650CFM Thunder AVS carb. The old girl runs like a pro but when she gets parked in the garage the gas/exhaust smell is shameful. I've done a lot of reading and think the evap can is a good place to start, as I've already installed an insulating gasket and fairly well ruled out other sources. I did, at one point, think it might be percolating fuel and thus the gasket, but it really hasn't helped. A fairly thorough search has proved that an evap can for a '78 vette is a unicorn and basically doesn't exist.

My questions are, Does anyone have a source for these? Are they rebuildable with some degree of success? Thanks in advance for the info.

 

Welcome to the forum.

If it's like mine, it might be the valve on top of the cannister. Mine was cracked and didn't allow the engine vacuum to purge the cannister which allowed it to get saturated with gas to the point where it was dripping on the garage floor. I sealed the crack and it's worked ever since.

 

Now I'm starting to wonder if I'm chasing the right problem. You see, when I put the car in the garage everything is fine. Within maybe an hour it starts to smell gassy, but not really like straight gas. More of a gas + exhaust smell. It will last half a day or so. After that, nothing... until she's driven again. Then repeat.

 

Could it be the cat?

 

Nope... cats are long gone.

 

Could it be running a little could it be running a little rich at low speed and idle?

 

Indeed. This is where my experience with this configuration, or lack thereof, starts to show. I would think if that were the case it would smell even if it were just idling for a few minutes and then put away. Just because I think it doesn't make it true though. I guess I'll be doing some deeper investigating and try to narrow the smell down. Might prove to be useful information.

 

I take it that it wasn't the canister.

 

Well, I haven't nailed it down yet. Partly because I've been busy and partly because I'm trying to hit it from a logical point of view. I myself am leaning toward a possible rich condition or some other problem that will cause fuel smell while the fuel system is operable, allowing that smell to linger, but dissipate when it sits for a while. Still digging though.