Ive had this annoying problem for a while I dont remember when it started and cant link it to any mods. The only performance mod I have is an AAM 3" single with stock y pipe and stock cats. Its a 2008 HR. I bought the car from a dealership in December with 30k miles and it now has around 37k. It doesnt happen all the time or when the engine is cold. It is really random when the idle bounces like this but it happens everyday. It most noticeable when I hit a stop sign. I stop then put it into first and right when Im about to give it throttle to takeoff it drops and then the little amount of throttle I give it makes the rev shoot up to like 1.5k. If I give it less throttle it almost stalls the car and jerks when I try to take off. Its not related to putting it into first cause I've tried doing that without taking off and theres no response. I took it to Project Import and the guys there say its "normal" and didnt checking anything. Only other thing that I find weird is the flywheel chatter but they also say its "normal". Its really random and managed to catch a video of it:

http://www.youtube.com/watch?v=AVAPICejnik]width=640

 

Pure Rush,

I've had this issue in the past with my '03 350Z as well as my '00 Miata and in both cases the culprit behind the erratic idle droop/hanging was a faulty Idle Air Control Valve. In case you don't know, an IAC (idle air control) motor is designed to adjust the engine idle RPM speed by opening and closing an air bypass passage inside the throttle body. To check the idle air control motor, remove the unit with the wires connected turn the key to the "on" position without starting the engine, the idle air control should move in or out. If the idle air control motor does nothing it has probably failed, replace it with a new unit and recheck system. I actually ended up being a cheapskate (or financially sagacious as I prefer to call myself ) and bought a cheap OEM IACV from http://www.nissanpartszone.com/nissan-350z-parts.html when I had to swap my broken one out. It was a relatively simple job too!

Another possible culprit could be that your EGR valve has taken a permanent vacation. You'll know if your EGR valve is stuck or malfunctioning because your car will experience symptoms like rough idle and bucking on acceleration. Are you experiencing any bucking during acceleration?

 

No acceleration is strong. Only the idle is rough. I'll look into checking that valve later today. Ill let you know

 

I tried your link but i cant seem to find the IACV on their site, do you know the part number by any chance?