I am currently having issues with running lean at idle until the car warms up. Even when it does warm up the a/f is about 15.2 which is still a little high. After I rev the engine when its warm, the car sounds like its on cams for a while and then it goes back to normal idle, but still a little rough. Today, I pumped up the brakes and the vacuum goes lower and the car almost wants to stall if i even pump it faster. Could this be a brake booster issue? Can the diaphram have any holes? My thinking is that if it does have leaks within the brake booster, then even when I pump the brakes, the vacuum will remain the same.