When I mash the throttle in the morning, or after work, I have to mash it hard the first time. Its like the throttle body is a little gummed up and needs cleaning. If so, anybody done this before?

 

First off, don't mash the pedal, it's plastic, and there is a change it could break. Yeah, it's probably the throttle body.

For some nice instructions, I'd go to the FAQ thread at the top of the X300 list. I know there are instructions in the ebook. Maby somewhere else too. You'll start by removing the air intake, and following up through the TB, undo some bolts, and it should come off easily. Make sure to put a bit of a gasket sealant on the TB before reattaching it.

 

I just had my TB off for cleaning a week or so ago ('97 XJ6 X300) ...not difficult. In this post: https://www.jaguarforums.com/forum/s...t=44083&page=2 is a link with several photos which may or may not be useful.

Happy cleaning!