So I have just recently picked up my 1st XJ. It is a 96 and all was great until this morning. I got in and started her up and the Check Engine light is staying on. I did the manual error code retreaval and found it to be error 25-the idle air control. I have read in the Haynes manual that I may need to take it to the shop due to the fact that replacing the IAC valve may not correct the problem. Should i just change it and see if the check engine light goes out or is there something else to check that could be causing this code?

P.S. Also when I started her up this morning I had to keep it revved up until it got warm or it would just die. Once It was warm I had no problems? Thanks for any suggestions.