Hi Jihm20 and thanks for your question.First let me say I hope you stated your question wrong. If your car idles 1-3 rpm up and down , not to worry. But if you are saying1000-3000 then there is a small problem.The port you are referring to does not have a vacuum to it. Unless it was plugged up with something like silicon or some other substance.For a engine to surge as you are saying is not normal.What happens when you drive does it serge when driving?there is a device called a throttle position sensor.If it ig oing nuts it will tell your cars computer it cant find the right place to set and the idle goes up and down.You also did'nt say if the service engine light was on or not.So what do you do? come back here with if the light is on and if it goes up and down when you drive and let us knowThank you for your question