Help!!!!!surging M50 engine!!!!!!

[<CHEISERMAN@xxxxxxx>]

Hi all. Recently my 92 325is had a problem. The car was warm, and running
perfectly. I stopped for lunch, and when I returned to start the car after
about 1/2 hour the engine started surging. It went from 500 rpm's to 3000
rpm's. Up and down. It was so bad it was undrivable. I had the car towed to
the local shop. At the shop the car was immediately started and it did the
same thing. The mechanic opened the hood and looked for a few seconds, and it
suddenly quit and went back to normal. He pulled codes (as I have no equipment
to do so), and found Idle Position Sensor. I left the car for two days, and it
never did it again. The mechanic whom I trust said that the valve could be
sticking, but did not want to replace a $100.00 part if he was not sure. I
have driven the car about 200 miles since with no other problems. I am worried
and am considering replacing the part myself as I am kind of anal about my
car. I want it to be perfect and fault free. The car has only 48k on it. Has
anyone experienced similar problems or does anyone have any suggestions?
thanks,
Corley Heiserman
92 325is

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