Fuel pressure regulator. It's on the end of the fuel rail. Has a vacuum line going to it, and a fuel return line running back to the tank. It bleeds off excess fuel pressure back to the tank at low speed. If it fails it puts full pressure to the injectors even at idle, and the engine runs way rich.
Quotes to live by:
guessing gets expensive
nothing is more expensive than a cheap BMW
Ken Kanne, Silverhill, AL, Honorary Forum Grandpa/Craigslist addict/Hoarder of all sorts of stuff
1995 318is "Bebe"; 1993 325is "Elvira" 1985 635CSi "Katja" 1984 633CSi "Sylvia"
I NEED A NAP, DANG IT!