Are you referring to the cold start fuel injector? If so, I have replaced it on my 87 535is several times...they have a tendency to leak, I have found. I also found that the car ran fine with it disconnected, but starting, particularly in cold, took more cranking(what a surprise) and idle was rougher for the first minute or so. Unless the wires going to it are shorted or something, there is no way it would completely down your car.