In trying to figure out the various issues with my 95 E320, I was checking the purge valve. (my car, apparently, while a '95 technically, has '96 engine components) It's the special edition from '95, not sure what that means, if anyone can shed light on that, just out of curiosity.

anyway, the purge valve...if I take the vacuum line (from the engine) off, the engine runs poorly. If I take it off and plug it, the engine runs fine. What is this information telling me? I'm assuming it's saying that the valve is working. I don't hear or feel any clicking though (I guess this is the sound it's s'posed to make?

thanks