Electrical/ignition Problem

[30ONA]

Does anyone in Brisbane have software to analyse my car? Something like data scan? Data scan is not configured for the V36 yet. I think I have a problem with one of the following but cannot be sure without spending thousands randomly replacing parts.

On light throttle (high load) there is a very subtle stumble, the engine feels smooth but the power delivery is on off on off. Give it WOT and it's fine. Originally I suspected the fuel 95ron, then the gearbox, then spark plugs which I replace. It also has a grounding kit. I have been using 98 octane and the problem has been there almost as long as I can remember. 2 years owned. People have suggested crank angle sensor, my mechanic has suggested a lazy O2 sensor. Does anyone have something they can definitive look at and prove something is malfunctioning? When I had my 300zx it was possible to see if you had a lazy O2 by looking at the duty cycle in data scan. I'm looking for something similar as I don't fancy replacing 4 O2 sensors on the off chance one of them is faulty?

P.S. Nissan won't look at it because it is an import and I don't trust them anyway.

[Nightcrawler]

You might want to read this thread from top to bottom.

http://www.sau.com.au/forums/topic/430930-v36-rev-probs-firmware-update-anyone/

[colin.ssc]

You might also want to read this thread

http://my350z.com/forum/maintenance-and-repair/307878-sputtering-during-warm-up-39.html

The general consensus on the 350z forum is the VTC system being too sensitive to motor oil viscosity. Some said to open up the VTC and clean it up, some said they tried a few different motor oil and problem was mostly gone. Or as Andrew said above, that thread had a firmware update.