when im driving down the road between 1200 to 1500 RPMs. my ideal starts go up and down. if im runing below 1200 or above 1500 everthing is fine.I have changed spark plugs,cleaned MAF sensor. also cleaned throttle body. Really needs some help anyone.

 

Welcome aboard. It might be helpful if you tell us your chevvy ride and visit the appropriate section for other owners to see.