FIXED FINALLY!!!:
Trying to fix my low idle since last spring cleaning,checking,replacing!!To find out (not visible)there was a fine tear from the rubber coupler on the intake!!! I checked and checked,felt nothing at the time but,decided to disassemble everything and saw a fine tear underneath the lining of the coupler.Fixed my low idle,quiet blow off valve sound,smoother ride down hill on the hwy(less sensitive to throttle)......finally!!

I thought I had fixed this low idle in warm weather thing by replacing the coolant temp sensor but,it is starting up again.Low idle (200 rpm)to almost stalling only happens when the weather gets warm/hot and it has been sitting outside.I have weeded out and fixed a lot of things last year including

-Cleaning IACV
-Adjusting and set TPS with/multimeter & feeler gauge.
-Checked hoses
-Replaced cap/rotor/plugs/wires
-Replaced 02 sensors./coolant temp sensor
-Cleaned build up from elbow hose on EGR.
-Replaced bad capacitor in ECU awhile back

I really thought coolant temp sensor would fix it since that's what it reads off of first before the car gets to operating temperature then reads from MAF.Any ideas?What is getting warm/hot that it tells the ecu to idle so low on start up?

Thanks for any input

 

If you're ECU hasn't been touched since the car was purchased new, I'd suspect the ECU contains a couple leaking capacitors. Miles do not matter...once you get over 15 years old...the gel in the capacitors start to leak out and cause malfunctions.

 

I've had the ecu fixed once from a bad capacitor but,that was when it drove horribly!!..I would think if it was a bad capacitor the idle problem would continue all day but,once it's in operating temperatures it goes away.It happens when the car is sitting in the sun.So some sensor/hose is cooking while it sits that when it is cranked with all the heat build up it idles low but,once it's moving and wind is coming in it goes away.I know someone out there has been through this.