A&Q about 350Z
Q:
Misfiring can be caused by a number of different failures, but in a newer car, it is usually an ignition problem. The ECU should spit out which cylinder is misfiring. They can replace the coil / plug for that cylinder.
Also, if it tends to misfire when the engine is fully warmed up, that also usually indicates an ignition problem.
On an older car, it is more common to have a clogged fuel injector cause misfiring. This usually shows up when the engine is cold, and is in the process of warming up. The fuel mixture is richer during warm up.
Any good engine tech should be able to find this problem. If it baffles the dealer, I would find a different one.
A:
Could be a bad plug or an injector or the hall effect sensor that tells the computer when to fire the plugs. I would go for the plugs first. They will probably put it on an engine analyzer to check the way the plugs are firing and how the coils are discharging. The Consult II will give the codes along with the aforementioned operating information. You might get in the back of the shop and get to check out what they are reading. Remember, under warranty they will have to disclose what they replace as they have to get the nice people at Nissan North America to pay them.
A:
Im glad I dont live in cali and can get better than crappy 91 octane...
A:
You could have water in your tank, or maybe a bad crank-angle sensor if these cars have them, or something like that that would throw off the timing.
A:
I'm hoping it was just water or bad gas & won't reoccur. It's running great today...puts that silly grin right back on my face.