Zeke's right about the Sol-vac, eliminate it. Its primary function is to speed up the engine to compensate for the added load when your air conditioning compressor or rear window defroster is turned on, but what can happen (and what happened on mine exactly) is that it stops retracting the arm when the vehicle is warmed up or the AC is switched off, thus leaving your jeep idling at--like you said--about 1100-1500 rpm. Zeke mentioned taping it off, but I removed it completely, including its mounting bracket, and plugged the vacuum line that used to lead to it at its source. I still run my AC, but the drop in RPMs is about 100-200, hardly enough to worry about. Beyond this, make sure that the fast idle cam (the yellow plastic thing with four "steps" on it) has "dropped" out of the way when the engine is warm--it should be a little bit loose to the touch to make sure that your idle is being dictated by the primary idle speed screw, not the fast idle screw that rides on this fast idle cam. Try this stuff and let us know.
Currently an '86 CJ-7---following a string of '01 Sahara, '90 Sahara, and '85 CJ-7. Finally got back to how it all began....