Ronw435

I just replaced the throttle body on our 1995 SL320. The reason I replaced it is that it kept coming up with a code saying it was defective and when you started it up cold it would idle around 600 rpm's but when it warmed up it would idle around 1100 rpms which to me is backwards. Well upon inspection of the unit when I removed it the insulation was all deteriated and falling off. Well I purchased a rebuilt unit and installed it. Now when it starts cold it runs at around 1000 rpms and when warm it idles about 550. The problem is that when warm it kind of surges at idle. Also the cruise control does not work, but it didnt before either.
Any suggestions?

Thanks
Ronw435