Solenoid question
 

I have a question about a solenoid under the intake of my 93. It's the one at the rear of the rack. It has a small tube with a filter on the end of it. I removed the solenoid rack and the filter part that is supposed to be sticking out the side was broken off. What does this affect? I really don't want to have to spend $50 on a new solenoid if I don't need to. Also, There are some black tubing lines that attach to two nipples on the engine. These nipples are also attached to the rats nest via vacuum tubes. My situation is that the black tube in the front is no longer attached to the nipple and it looks like it's dripping oil. I will reattach this line to the engine but I was wondering what the purpose of it was.