97 xk8, when in idle i get some jolting like everything is cutting off and on. then i drive off and everything is fine. Now i do live in Dallas and hot weather is a factor. is this a fixable issue? or something that I deal with being a jag owner in texas. throttle body or air mass? trying to narrow it down

 

Have you checked for OBDII fault codes?...they often provide critical clues.

 

I'm in Dallas too. What you describe is not normal. As Whitexkr suggested, check for fault codes. If you don't have a reader, any Autozone will pull them for you for free. Bring back the actual P-codes (not their diagnosis) to the forum for help.

 

The first thing to look at when the idle is jumping around is an intake air leak after the MAF. The XK8 is famous for getting leaks in the accordion plastic intake. Just start feelign it all up. A tricky place for a leak is a broken air pipe to the EGR.

 

Also, make sure your throttle body connector isn't broken, the pins are clean, and it is seated firmly. The early xks suffered from poor contact in that connector, causing all sorts of power loss problems, including just casually driving at highways speeds. There are threads discussing changing the pins over from tin to gold also to help conductivity.

 

Get the OBDII codes as suggested anything less is a guessing game.