84 733 IDle too High

[changabe72]

Can anyone help me out? I have a 84 733I with about 270000 on her. She has an unually hight idle, about 1500 in park. The idle starts out around 900 when first started then rises to around 1500 when warmed up. She also lets a blueish puff of smoke when started. I have replace the tps, fuel regulator and waffle box. I tried also to adjust the idle to no avail. None of the tricks I have used seem to work. The basically drives itself at time vrooming up to 20 mph without me even hitting the gas pedal. I have also tried to adjust the throttle cables but that didn't help either. I am all out of ideas and really don't want to take it to a dealer. Thanks