Rough Idle...

Ok, I have a 92' 240, at idle the car is really rough. Sometime it will just die. Normal driving seems to be ok except when i shift it kinda jolts or if the clutch is in long enough for it to get to idle it may die like i said before. Ive checked all the basics(Plugs, Loose Wires, Vacum Leaks, etc...) and cant find anything. First thought was maybe a knock sensor but, I did some research and looks like it might be a so called "IAA" valve or and "AAC" valve. Kragen, Car Quest, etc... dont know what I am talking about but I went to nissan and talked to the guy there and we found an AAC valve that I can order but its like 200 bucks. Any of this sound familiar to you guys. I want to make sure i know what it is before i go buying something i dont need... or if there is another fix... Any suggestions may help.

clean your air intake valve, and intake piping. then up the idle by taking a philips screwdriver and there will be a spot on the passenger side of the engine where you stick in the screwdriver and adjust the idle. bring it up a couple hundred rpm (after you clean the aiv). if that doesn't solve it i'd say take it to the dealership

Yea, I have cleaned all that before...so there shouldnt be to much buildup in there, I actually took my whole throttle body off before cleaned the whole thing with carb cleaner and a toothbrush, put it back on with a new gasket... But ill check it all see whats up.