name this vacume line.....

[XJ DRIVER]

:confused: I have a vacume line on my 89XJ that comes out of the fire wall it is blue in coler and it had a black wafer like valve on it and I cannot see what it connects to.

[Yucca-man]

Can you post a pic someplace? This reminds me of the differential vent tube from what I remember under the hood of my 89