Wuttin

Folks,

Recently did some vacuum work and have noticed a solid boost in performance. The vacuum canister on my 79 L82/AC/Auto car looks completely original and untouched = in need of attention. I have none of the original air/emission equip any longer.

Questions:

• Do I need it? why?
• Can I bypass it? How?
• If I take the canister off line how does the fuel vapor return line get tied back in?
• What is the minimum refurb that reteins function but doesn't impact performance?

Thanks to all, Steve

Vette79C3

I replaced my original with a new one from one of the vendors. The fuel vapors were getting to be a bit to much. I'm watching this one closely as I have heard it is not a good idea to remove and there is no real benefit if any in removing it so curious as to what others think or know...

SIXFOOTER

I'll take a shot;

You don't NEED it, but it is a good idea to have it on there as it sucks up gas fumes that tend to collect in the garage, it recycles the fumes when you start up next time.

You can simply clamp off the lines going to and from the canister or remove it entirely, but would need to cap the vac source lines.

If you do remove it, the fuel vapor return line would need to be capped.

Minumum I would think is fix the leaking lines, and maybe replace the canister with a new one. If the system does not leak it should have no impact on performance. It doesn't do anything while running down the road, only at startup and after shutdown.

I think you can get new stuffings for the canister, but no idea where.

Vette79C3

If you do remove it I think you will then need a vented gas cap. Also, the vapor canister can be removed from under the vette. I could not take my original one apart. I could replace a small round thin filter on the bottom but I believe there is charcoal inside the canister.

7T1vette

From a performance standpoint, there is no benefit to remove it unless the engine is ingesting air [via some kind of vacuum leak] rather than collected fuel vapors. Too much air would be the same as a vacuum leak in the intake system; but such a leak would mainly impact idle and low throttle condition...not WOT performance. If your system is hooked up correctly, has a non-vented gas cap, and doesn't generate fuel fumes in your garage after a run, it would indicate that the system is working properly.

Vette79C3

Keep it or replace it if necessary.

Wuttin

Thanks to all...excellent, replies.

I'll do a replacement of the vacuum lines and inspect the canister to make sure all is intact. If the canister looks good I'll leave alone, otherwise I'll swap for a replacement. I'm a driveway car so I don't get any post-cruise fuel vapor buildup (that I notice at least) so kind of hard to tell on that basis. I know the lines are tired so I may have some vac issues. Replacing some of the lines at the carb during my recent headlight restoration greatly improved the idle so hopefully it'll get even better if I refresh the canister lines.

Wave on, Steve

markdtn

There is no off-the-shelf vented gas cap available. You have to make your own and that introduces the possibility of water getting into the tank. I would make it work, wish I had on the 'Vette. I did on my TPI swap in my truck.