Heres a video of my FD but whats being shown is my bros skyline and my fd is the car you hear in the background it was on turbo timer but its the only vid or sound I got of it making that sound help?

http://www.youtube.com/watch?v=1dj0N0oqSA8

 

It sounds like your MAP might be unplugged? i dunno

thats what my friends sounded like when his MAP was inplugged. but then its a really smooth change in idle... i dunno

 

mine will do this as well. How does the car drive?

 

I know the Answer to this. It happen to me all summer and I could not figure why it had the bouncing idle (very FRICKEN annoying). People been telling me that theres a Vac leak in my car. So I replaced all my Vac lines and the same thing. After all this hassle I found that it was the Throttle Positioning Sensor. Check to see if its any good alot of times it just needs to be re adjusted. I just fixed it a week ago.