Idle Surging

[3O3EL0VR4]

So now that I finally have 671 back to a daily drivable condition, I have noticed when I am sitting in traffic the operating temperature is completely fine but as I start driving the temp goes way back down, almost all the way to the C. Which, I didn't realize it until I was coming to a stop and getting an idle surge about 4 or 5 times from about 1k to 2k rpm. Then, the temp gradually goes back up and the idle surge doesn't rear its ugly head any longer. At first I thought the huge radiator and giant FMIC was to blame but, I know this is a classic symptom of a thermostat being stuck open.
What my question is, does anyone know if the ecu reading that cold of temperature would cause the idle surge? My theory is that when it reads cold it is making the IAC sensor want to run higher rpm's??
I'm going back to Mitsubishi and getting a thermostat tomorrow so I can put it in this weekend.

 

[3O3EL0VR4]

Decided I couldn't wait and installed the new Mitsubishi thermostat last night. Idle surge is basically gone now. When it cold starts, it still does but hardly at all and not nearly as rough as before. I'm happy I did it last night. I get a drop in RPM's, almost like sometimes she wants to die when coming to a stop, and disengaging the clutch, but catches itself before it completely dies. I'm looking through other posts to find out what other sensors are related to this.

 

Did you ever figure it out?

Mine does the same thing sometimes

 

[3O3EL0VR4]

Sorry I have been super busy these last few weeks moving into my new apartment, dealing with my upper intercooler pipe blowing off (which I will be posting pictures of the new one soon) and schoolwork. I haven't figured out the reason for the drastic drop in RPM's but, it seems to come and go. Yesterday, it didn't happen once, yet three days ago it was almost dying at every stop sometimes it would. I still have a few more thing I need to check before I could supply any definitve answers.
However, I did find this thread ( click ) to be very helpful for coming up with ideas and things to look into.
Hope this helps and good luck!

 

[VR_IV_MR]

i have same problem. someone mentioned it was from the lightweight flywheel. I try to just let the engine rev down before dropping it in neutral when coming to a stop, however in case of emergency stop, I have still stalled out... RPMs also tend to get very weak during a u-turn or while parallel parking. /ubbthreads/images/graemlins/frown.gif