My 1g 7 bolt, will start fine and after a minute will idle up and down, but when i drivem, it's fine, any suggestions?

 

Idle up and down? Does it bounce from idle to about 1500 back and fourth? Does it do this when your slowing down to a light and have it in Neutral or when you finally stop? Usually when idle goes up and down more then once and does it repeatedly its a sign of idle surge.