I wouldnt bother insepcting for vacuum leaks, rather hook up a vacuum gauge to check the vacuum. The gauge should be stable around 17-22in/hg. Anything less would indicate a vacuum leak somewhere. Then you can inspect from there. Also clean your pcv valve out also, it should rattle if its working properly. If vacuum is good I would move on to the fuel system. When is the last time you replaced your fuel filter? If it has been awhile I would go ahead and replace that for the hell of it. That could be your problem.