Hey, my 03 Disco revs to about 2000RPM for about 1-3 seconds upon a cold start... I've cleaned the throttle body multiple times, and have even tried taking WD-40 to the throttle to make sure it's not getting stuck, but after a few cold starts every time it starts revving high again. Any suggestions?

Not really sure how to go about fixing this one.

 

Coolant temp sensor behind the alternator/AC is either faulty, or the connection is bad. The ECU thinks the coolant is colder than it is, and starts the motor as if it were fifty below zero. You can pull out the upper connector and clean the pins a bit to see if it helps, but otherwise replace the sensor. You can do it with AC compressor out of the way.

 

Okay thanks for the suggestions, I'll take a look at the temp sensor. However, one thing to note, when I run dashcommand, the temperatures that I receive seem pretty constant (between 180-190). Would it be displaying the correct coolant temp if it was faulty? Or no? Thank you buddy!

 

I would inspect the Idle control valve.

 

You could try cleaning out the idle air control valve and the throttle plate possibly.

 

I have cleaned the idle air control valve, but not the throttle plate. Revving returned after idle air control valve was cleaned. I'm tempted to spray some WD-40 in there as well, but I don't want dust to get in there and lock up the inside mechanism. Thoughts?