1995 BMW 318ti 100,000 miles 4cyl. I just replaced the idle valv and still have the idle jumping up and down from 1000 to 1500. Sometimes when I rev to 3000 it stays stuck. I read other answers you posted and said something about dirty particles may be causing this. Please let me know how to fix.
This sounds like a crankcase vent valve gone bad. The BMW part number is 11-15-7-501-567. While you are in there check for vacuum lines that are old and need replacement, and oil soaked vapor lines that are in need of replacement. Go to realoem. Com and there is an exploded view that should help you out.