Sorry, realized after I posted it wasn't the most useful info ever.

Two ways to check it.

One, with the car off, pull the vacuum hoses off of it, and suck on each one. You shouldn't be able to keep sucking air through them. Or, if you have a vacuum pump, you can take the cap off, and watch the arm attached to the diaphragm to see if it moves when you apply vacuum.

Two, which doesn't really apply here since it isn't idling real well, you can pull off and plug the lines while it's running, and the idle should drop or the engine should die. Either way, the idle should change for the worse.