okay so i've had my jeep for about 2 months now and ive noticed the same thing over and over again that has to do with the idle. it seems to idle at any rpm between roughly 175 to 300. and even after its warmed up it continues to do this unless out of the blue it idles nicely at about 500 rpm.
everything on the jeep is in perfect working order just wanted to know if this is a common thing with xj's.

 

You will have check all your sensors, TPS, IAC, MAP etc. I had the same problem and after checking sensors it turned out to be an out of adjustment TPS.

 

Remove and clean the IAC, and check for vacuum leaks.

 

x2

 

x3 on the IAC do a good TB cleaning and see if it helps

 

ive checked all my vacuum lines and couldnt find any leak anywhere. but i will check all the sensors. thanks guys