"Fixed" my idling problem: 1987 325
Just bought the car, & it had that notorious surging/revving problem where after reaching operating temperature, the engine would rev between around 900 & 1500 RPM.
I bravely(perhaps foolishly) decided to try adjusting the Idle Air Stabalizer Valve screw (remembering where & how much I was turning) & I found that with 2 turnsclockwise(into the body of the valve) the engine is now settled around 900 RPM.
Much better I think than that other buisines!
I hope it stays!