my throttle body junked out (99 xj8). I ordered a new one and this one has the air assist where my ild one dose not. Question is, its just a vaccum port right? Can I just tap into a vaccum place and stick a hose on it?

 

Are you referring to the black cylinder on the top with a vac connection? That would be the cruise control bellows used on AJ26 engine throttle body.

If you have no cruise control just leave it disconnected, if you have the later electronic cruise control you may have the wrong throttle body for that.

 

Pretty sure you have the wrong TB on order. (they are not interchangeable)

I *think* 99 was the year with the switchover. FROM vacuum cruise TO electronic cruise)

If you can take pictures of both and post links to the pics we can tell you for sure.

 

Yep - wrong tb, you'll need the earlier version mentioned. It won't work because of different electrical programming.