wonder if something is up with the ecu's coolant temp sensor...

does it do this regardless of outside temp, or does the idle only go crazy on cold starts below a certain temperature?

 

It first started when the temp first dropped below 45 degrees, or so. It is worse in colder weather and not as bad in warmer weather (warmer being 45 to 60 degrees in the Chicago area)

 

The coolant temp sensor tells the system how far to adjust mixture on cold starts. If you have a scanner, unplugging my coolant sensor made scanner read -40 F. So you might have a bad sensor, or bad wire, and it might show up as an out of this world reading on a scanner - when it is + 25 F outside, the motor should not think it is -35 F, etc. From the grille, look at upper hose where it enters engine. Two sensors are vertical to the right of that, the single wire runs the temp gauge, and the two wire with kinda square plastic top is the coolant temp sensor that drives the ECU. Pix - https://landroverforums.com/forum/at...s-p1120328-jpg

 

I'm going to go ahead and back up these guys with the coolant temp sensor going bad.
The one for the ECU, not the dash gauge.
The one you want is ontop of the engine next to the thermostat.

 

Thanks, again, for the advice, guys. I will borrow my buddie's scanner and check this out. I will let you know the outcome in a couple of days.

Appreciate it!