I have no idea what this is it is in the very front of the engine bay on the driver side just behind the head lights , i was hoping some can tell me what is for and the right line leads to two other lines and they are not connected to anything so if someone could show me where they go it would be appreciated and this is on a 88 2.8

 

Cruise control diaphragm. When it is actuated, vacuum pulls in, and the cable pulls on the throttle body.

 

See attachment for hose and cable routing.

If you look at Item #6 (the square with the "6" in it); that cap attaches to a "tee". In actuality, that "tee" is a one way valve. This is super important to have. If you don't have that valve, the cruise control will not hold the throttle open when the engine is under load (like when climbing a grade).

The valve should hold vacuum on the cruise control diaphragm side, and be "open" on the engine side.