One way to check for vacuum leaks is to spray engine start, or some combustable spray, near all the vacuum lines while the engine is running. If you get to a spot where the idle increases, that's where the leak is. The leak will suck in the fumes from the combustable spray and cause the engine speed to increase like you pressed the gas pedal. But, be careful not to blow yourself up!!!! This can be dangerous. Especially with a hot engine. I did it from a cold start where the idling seems to be hitting hard the most.