I had an issue with my IAC Valve (so I thought). Here is what was happening. My idle would always be elevated when coming to a stop, lets say around 1500-1800 rpm. Once I would come to a complete stop the idle would settle back down to around 700 rpm after about a 3-5 seconds. This issue would go away when I unhooked the IAC. Other than throwing a code it would run really good with it unhooked especially when I would come to a stop. I installed the new/but used IAC and took my truck for about a hour drive stopping several times. All seemed to be fixed. The next morning and ever since it is right back doing the same thing. Do you have to have the IAC set by a dealer using test book? Does anyone have any ideas on what could be causing my issue?
Thanks to all.
Jason

 

Some have had good luck just installing a new IACV and other have had to have it set by the dealer.
Your dealer may or may not charge you for a new one.
The IACV from a Jeep 4.0 is a direct plug in so I have been told and is under $50 brand new.

It could also be a bad throttle position sensor.
Or a clogged IACV port, dirty throttle body or a vacuum leak.

 

I bought a new one for a Jeep 4.0 and there is a small difference in the plunger. The Land Rover's IAC has a small lip on the outer edge of the plunger. I tried the jeep part first and had the same problem so then I decided to get a used one to try. I may have to make the 100 mile drive to the closest dealer.
Thanks,
Jason

 

Have you cleaned your t/body?
You will most likely need to do as Spike mentioned and get it reprogrammed.

 

My original symptoms were a very low idle. I bought the Jeep 4.0 IAC. And after the replacement I had the exact same symptoms as you. I had a local shop reset the values for the idle and the issue returned. As you I was getting ready to give up and consider the purchase of an LR IAC, but the shop talked me into spending an hour trouble shooting before taking that step. Glad i did. They quickly found a short in the wiring harness that was at issue. I was happy to pay the 1 hour of shop time to diagnose and fix. Worth a shot to check it out anyway.