Mods in sig. Car is idling @ 2000 when rolling.
At full stop idle drops to 1000 and surges to 1200 every 2-3 seconds.

Any ideas?

 

question is, what has been done, tuning, TB etc??

 

Seems to me, you have a vacuum leak. Have you removed the intake or messed with the idle set screw on the throttle body?

 

Sent my TB and ECM to MTI for checkout. They lowered the idle in the ECM and gave me a TB blade with a smaller hole. MTI continues to impress with customer service. Installed and still have same problem. I've been talking with MTI on the phone and they seem to think it is vaccume leak also. I pulled the pcv line near the TB on the intake and capped it, same problems. What other source of vaccume leaks can there be? Sometimes car runs perfect.