Bad Idling Problems!!!!PLEASEHELP!!!!

Hey guys, my buddie has a 1984 BMW 325E, and when he starts it it idles really high(5000rpms) and stays there for a good solid 30-45sec and then idles down and intermitenly revs from like 800rpms to around 1800-2000rpms and its not a slow rev it is a pretty fast an constant rev. I have changed the Throttle body with tps and still is same as it was. I have had this problem but the tps has fixed it. I have checked all the visible vacuum hoses and they all look good. Any help woul be greatly appreciated.