Hi, i am from Germany and have a european 350Z.
I have since I have changed the spark plugs (intake manifold and throttle was down) a high idle. It is about 1000 rpm. I've already checked for leaks, negativ. Also relaarn the idle and had my battery off for a night.
When I relaern the idle I had 750 rpm, but once I turn the ignition off and then turn it on again, I have 1000 rpm.

Can somebody help me?

 

I wouldn't worry about it too much. Even in the states, my Z idles at 1400-1500 rpm when its cold. When its warm, its usually at the 800 rpm mark. Hope that helps. Are you talking about a cold start? Any mods?

 

No, i am talking about a warm Engine.

 

I had pretty much the same problem and it did not go away away until the throttle body blew, well actually the pedal position sensors on the TB. Replaced the TB with a reman from Nissan and been perfect for 6 months now. Same as the OP, was fine after the reset but only until the next time I started the car. Kept throwing a SES too but only code was "High Idle Detected". Like duh!