I have a few issues going on with the IAC and O2 sensors but I'll address the sensors in another thread.
My 02 Galant 3.0 suddenly would not cold start without some pedal applied. The colder the outside temp the worse it got.
I messed with the idle adjustment (yeh , i know) but i've put it back to about 750rpm idle. Code 506 comes up. I clean the throttle body and the IAC today. Now the manual says I should hear a click from the IAC when the key is turned on,not started but I don't. While I had it out but still connected it would sometimes jerk with key on and I picked it up and you could still vibrating like it was trying to do something and sometimes nothing.

Should I be able to depress the spring loaded mushroom looking thing cause it doesnt move at all.
I'll buy a digit voltmeter tomorrow and check the ohms. What should they be at? Anyone know which pins to check on?

Any other ideas?

 

you need a new IAC

 

I got a dig voltmeter to test the IAC and yeh it's definitely bad. Found a few on Ebay for $50 delivered.
Also have one bad O2 sensor. The rear sensors should be 11 to 16 ohms and the front 4 to 8 I think.