Today I started it up and drove it to work 11 miles and it ran fine.
When driving to lunch today I noticed it shuddered under acceleration. light acceleration it shudders, and it gets bad under hard acceleration. It shuddered through all gears, but not while idling or if my foot is off the gas. I turned of the TDC and it still shudders.

It will still accelerate, it just shudders while accelerating.

I'm wondering if its bad gas? I have put about 150 miles on this tank, I'm going to fill it up on the way home and see if that helps.

background on the car:
I have owned my 04 350z Roadster for about 2 years. It has 86k miles, I have put 25k miles on it. It has ran flawlessly until today. I drove it about 150 miles yesterday, about 60 miles was through some mountain roads and I was driving aggressively.
I have done all of the services, I ran amsoil in the engine, trans and diff.

If anyone has any suggestions please help. I live in Chino, CA and I am thinking of taking it to West Covina Nissan, anyone have any suggestions?

 

Sorry to hear your problem! I'd start with the obvious/easy things first:
Bad gas? gas treatment/fuel injector cleaner (Techron).
Air filter ok?
Orig plugs been changed?
PCV changed/cleaned?
Might be a poor electrical connection. Mb check battery, MAF,throttle body, coil paks seated properly.
Good luck. Keep us posted!

 

You will likely be able to get a code. Hopefully that will provide the information needed for a fix. --Spike

 

my car is doing the exact same thing. changed the coil packs and it resolved for about a month now its doing it again. really dont want to believe the car went through another coil pack its really annoying tho. at wot the car shudders and then has moments where it jolts forward (like the stars align and the car drives as should)

 

How did you determine it was the "coil packs" causing the problem?

 

I agree, plug in a reader and see if anything shows up, at least it should point you in the right direction.

 

This happened to me, what I would check:

1> Check for codes (autozone does for free) (keep in mind it may not actually give you a light but the ecu will remember the fault)
2> Remove, inspect, and measure all spark plugs. ( also check for oil in spark plug canal)

If you get a missfire code( like I did) swap plugs with another cyl. See if issue occurs or missfire moves to different cylinder. Also check the connectors to all cylinder coilpacks, as the clips become brittle with time and can break, and walk on you.

(also happened to me and I have 2 of them zip tied down to their coilpacks)