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
buying a ratty example (of a BMW) is a parasitic relationship.(and you ain't the mosquito)
Ken Kanne, Silverhill, AL, E36 Forum Mod/Craigslist addict/Hoarder of all sorts of stuff
1995 318is "Bebe"; 1993 325is "Elvira"; 1985 635CSi "Katja"; 1984 633CSi "Sylvia"; 1987 325is "Odette"