I've been struggling to find a minor vacumm leak for the last few months. I'm happy to report that I finally found it!!!! If any of you guys have a vacuum leak symptoms that are puzzling you, I would suggest that you check your vacuum advance. I checked and re-checked all my vacuum lines multiple times only to find by accident that the diaphragm in my vacuum advance pod was either sticky or punctured. To make a long story short, 20 minutes under the hood gave me a new vacuum advance and no more vacuum leak symptoms. Here's a question- What exactly is the vacuum advance diaphragm made of? And what would cause it to puncture or get sticky? Anyhow, maybe this will help one of you out there.