Jeep: Parts diagrams for 88 YJ 4.0L

I was looking on the internet for a full set of diagrams for my YJ...I have
a piece on the passenger side of the engine that I need to order...and I
have no idea what it is. It appears to have been a "ball" that was between
two lines, of which looks like a vacuum line... Any one know what it is, or
where I can get diagrams online rather than buying a Chilton's?

Thanks in advance
Bruce