BMW: Idle surge, vacuum leaks, coolant temperature

Question
I have a 1985 318i and the engine has started to surge after the engine has warmed up (about 15 min.) I have installed new plugs and wires, roter and coil.
This work was done at a shop as i do not work on cars myself, would a tune up useing a dyno-monitor  be helpful?
NOTE: I am the second owner of this car with about 165,000 I paid $500.00 and the car is clean.


Answer
Mario,
 So the car only does the idle surge AFTER the engine is up to operating temperature?  There are some coolant temperature sensors that tell the on-board computer that the car is up to temperature, one of these may be malfuntioning and causing the surge.  You should also check for vacuum leaks and clean the idle control valve.

 Hope this helps,
 Josh