BMW Repair: BMW Idle surging problem, bmw 320i, oxygen sensor

Question
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Followup To
Question -
I have a nice little '83 BMW 320i that has started to surge very badly (+1500RPM) at idle and while driving.  I have changed the oxygen sensor but it didn't help.  What else should I check?
Answer -
Possibly a throttle position senser? Try disconnecting it and see if the idle stabilizes.
I assume the trans is not slipping.

Thanks. I gave disconnecting the TPS a try but the idle still fluctuates between high then normal rpm every 2 seconds or so.  It seems to be worse after the engine warms up a bit and not as bad when its cold.  Any other thoughts?  Sorry, I should have mentioned before, this car has a manual transmission.  

Answer
Next thing is to disconnect the idle control valve.That car is a little before my time but if it is like the early 325 the car should idle around 700 rpm with it disconnected electrically.  The early 325 had a seperate control box just for the valve that went bad.