Bryant1234

Hello everyone my 87 944S 16 valve runs great until I stop the car and it just shuts off. Sometimes when I stop it doesnt cut off but it drops to low rpms like 650-750 and bounces up to 1200-1300 and it does that a few times till it stabilizes out around 1K rpm at idle. I'm thinking ICV or Vacuum leak but just wondering if anyone else has any idea of what it might be? Thanks in advance for the help everyone