Alright, so I picked up a sc300 and it idled at 1900RPM then slowly dropped down to the standard 700, but after driving it to the gas station, it was idleing at 200rpm and surging a tiny bit, not more than 50rpm surges. As soon as you leave idle, the car drives prefectly and there is no surging or any indication of a poor idle. I'm thinking IACV or a dirty maf, maybe a vacuum leak, anyone know a fix for this?

 

The IACV does sound like a pretty good lead. When i took it off to clean it, there ended up being a quarter inch of buildup on the prong that adjusts the airflow. Good luck and keep us posted.

 

IACV, or vac leak would be my guess.

 

I checked all of the vacuum leads, none looked old enough to be cracked or were disconnected, the IACV looked to be an aftermarket unit aswell.

 

Carb cleaner will take care of that.

 

Funny you say that, I went out right after posting and cleaned the TB with carb cleaner and it fixed it, lol..

 

I have this same problem... only weird thing is my idle problem started AFTER cleaning the TB... maybe taking apart the IACV and cleaning it will help me HOPEFULLY. same as yours mine drives like a dream but idles like a nightmare

 

my car drives fine but at idle the needle sits right at 100rpms some times so 0