Intake "psst" noise cause and poor cold engine startup?

When engine is idling there will be these random and short "psst" noises and the cars idle will change for a second in response. It will sound similar to an air hose for airing up tires being used and disconnected real fast. All vacuum hoses are replaced, wiggled them and it does not make a difference. Sounds like it is coming from under the intake. Removed and inspected for cracks but problem persists. Started having serious problems cranking from a cold startup as well.