Hi Walknight;
The black line you are talking about is a vent line its in the clean dustfree area for venting. This way no dust will get in sysytem tru that line. Its almost every one's nightmare to open the kick panel and not notice this line at once, but you get to see that line after working on other things and it scares you to death when you dont know if you knocked it loose. Let it be there in such a way that nothing will block it. If its really loose tie it ti steering column nusing with a tie. You can find this line in MB disk under the topic Engine then subtopic fuel infection system then sub-category "checking vacuum shut off for leak". Its on the 3rd or 4th page of this pdf file.

MVK

__________________
One penny saved is three penny earned.

1985 300D Turbo 179,000miles