Hi there - 1980 320is
i got my car for 500 bucks from a guy who didn't know how to change a tire. the sparks were fouled up so badly the gap was almost gone. the spark cables could barely hold onto the plug - they were busted and threadbare. the O2 sensor was black with charcoal. the thing still ran on the interstate - these engines are amazingly tough.
so i replaced the junk stuff, change the oil, and it runs so smoothly now. but the idle won't stay still after it starts up. it oscillates between 500 1100 rpm until it gets nice and warm, then it steadies out around 900. why does it do that?
see you all round the corner!