91 525i idles at 5000 RPM!!!! HELP!!!!!

[Metalmatt87]

I have a 1991 525i 5-speed that I just bought a couple of months ago from an impound lot for $800, 196,000 miles, absolutely beautiful condition and everything (including the A/C) still worked. The car ran and drove like a new car for about a week and a half until I started to notice that it was idling a little high...around 1300 RPM. I pulled off the air intake hose and saw that the throttle body was pretty carboned up, so I cleaned it out with some throttle body cleaner. As soon as I fired it up it started to idle around 2000 RPM and the check engine light came on...TPS fault code. I read in the Bentley's service manual that you can fry the TPS by shooting throttle body cleaner directly into the throttle body and that you should use a rag soaked in it instead. Oops. So I fried the TPS...not a big deal. Got a new TPS from BMW and the idle went down to about 1600...not good enough, but the engine light is out. On a whim (and the fact that it had junkyard writing on it) I unplugged the Mass Air sensor and it went down to 1000 (getting better) but obviously the light came back on and it didn't accellerate very well. Plugged it back in and drove it about 10 min. with it idling at 1600...then it went up to 2000 again. By the time I got home it was up to 3000 (THAT was an adventure). I pulled the intake manifold and found a couple of cracked vacuum hoses, a bad IAC hose and a bad breather hose. I replaced the hoses, checked the IAC for proper operation, and put it all back together. Fired it up and it immediately went to 3500 and within 5 seconds went up to 5000. WTF?!?! I checked all the wiring, Mass Air, TPS, and IAC according to the Bentley's manual and everything is 100% OK. I am now pulling my hair out trying to figure this out. Other than this issue, I absolutely love the car. I am a tech with 15 years experience, so its not like I don't know what the hell I'm doing. Somebody PLEASE give me some idea of what's going on. Your help will be tremendously appreciated.