Did a search all over and no recommended idle RPM is listed here or anywhere on the Internet. I'm at 1000RPM and IMO, it's too high...

 

Agreed, 1000rpm is too high, BUT, what car do you have, and what engine, V12 or 6cyl. Add that info to your signature, it helps all and sundry to reply quicker and more accurately.

I am going to guess that its a V12 with the AAV (Auxillary Air Valve), on the rear corner of the LH cylinder head, sticking, which is common, and well covered in "The Book" by Kirby Palm, and freely available from various sites.

Most Jags sit on about 750-800rpm.

 

Including the FAQ for this section.

 

Correct idle speed for V12 is 750rpm. Should be set with car warm, idling, ALL ACCESSORIES OFF, especially the A/C.

Adjustment is by turning the bolt on the AAV, which is located at the rear left hand side of the engine. It's a common issue that you end up turning this bolt all the way in and the idle still doesn't drop. This points towards potential air leaks or a failure of the AAV itself...... so, try adjusting yours and see whats happens