Just started a couple of weeks ago, normal idle is about 700, now after driving a bit when I come to a stop light, it revs very high, put it in neutral and notice idle is at 1500+, if I kick the throttle idle goes back to normal, but then it happens again a few miles later!......Any ideas on where the problem may be?

 

Could be Dirty Idle air control valve, dirty maf Sensor, dirty throttle body, Throttle position sensor failure, Dirty air filter. These are all symptoms. Do you have check engine light?

 

Yes the check engine light has been on since I bought it last year, but it only started this idle problem a few days ago.

 

That happened to my Disco and after cleaning everything mentioned in reverse order from above, the final culprit was the IACV.

 

If you have a scanner tool find out what the code ir codes are? If not go to O’Reillys auto parts have them check for code or codes. Now it won’t fix your problem but will give ideas of where to look.

 

Cleaned all of thoseparts, the IACV was really filthy....seems to idle OK now. Thanks for your help!