I have had a hesitation issue. It is 100% repeatable and passengers including Nissan agree I am not crazy. Cold start is perfect, runs well. When the car has almost reached temperature the rev needle bounces up and down and the car loses power intermittently causing a very obvious jerkiness every 10 seconds or so with light- moderate throttle.

If you plant your foot when its doing it, it will run smooth again. It does this for 1-2 mins and then it is perfect again no problems.

Nissan cannot find any codes, engine data but they agree the problem is there. I changed the original platinum's for some new stock equivalent iridiums and there was no difference at all. I have cleaned the MAF and put in a new air filter. Any suggestions appreciated, thanks.

2006 350z, 60,000 miles 6MT.

 

Does it sound like this?

http://youtu.be/iA2pGGWOk6g

 

Was there any oil on the plugs? Do you have a cipher cable or scanner so you can look at the long and short fuel trims.

 

No, not really, thanks for the clip. I will go and video it tomorrow or the next day and post it up so you guys can see what is happening.
No oil on plugs. There was a tiny bit of oil on the threads only of plug 6, not on the electrodes. Apart from being old and worn they looked great. A nice medium gray colour, not too light or dark. Also no oil down the spark plug holes including plug 6 so no leaking valve covers.

Nissan wants to keep it for 2-3 days and attach some recording "stuff" to it so they can get readouts of what is happening and send it to Japan for analysis. I don't have any equipment for this sort of thing. I am thinking about it but they are totally useless, they can't even give me a rough estimate for gathering the information.

 

Because their going to hit you with a bill that you would have said no to in the first place.

 

Yes most likely.

Here is a video of it. This starts about 60 seconds after starting the car and driving. It lasts about 30-60 seconds (less than I thought originally) and then the car drives normally no problems after this. Whenever you see the rev needle jumping up and down you feel very brief but obvious hestiation (starts about 2 seconds into video). The car doesn't sound any different during this. Its actually been better the last week.

I am starting to think it is "normal" and might be the same thing that everyone else is complaining about in the "spluttering during warm up" sticky.