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[02RhinoRange]

I brought it to a local mechanic who cleaned out the throttle body - he said it was full of carbon buildup- and that fixed the problem.

mine did it to, cleaned the idle air stepper motor and no problems since.
http://www.rangerovers.net/newrremedies.htm#stepper

~Both from this RangeRovers.net thread


If you don't already know, RangeRovers.net is a supurb resource of information on your Rangie, there's technical "member submitted" articles for repairs and solutions, and there's also a great forum that the above quotes and threads came from. It also has a great search function, give that a go.
Hopefully you only need a throttle body cleaned and you'll be good to go.