Poor idle control with AC on

[Rover Range]

You can try cleaning the throttle body housing.
Could be the ac compressor dragging the engine down.

Check basic stuff like air filters.
Also, try disconnecting the battery for 10min. See anything changes.

 

[djkaosone]

There's no IAC on the LR4.
The vacuum motors on the rear of the intake are for the air diverter valves within the intake. Doesn't affect the idle.

Hmm... I had no idea that's what it did. Thanks for enlightening us (me)!