Yeah that sounds right based on what I've been experiencing. Mine isn't as bad as it used to be however (it used to be every time I started it up if it had sat still for long at all). Now it's... intermittent, but it still happens too much.

If I could be SURE it was going to happen "next time", I'd have it at the dealer now.

Does anyone think we could get some actual interest from Nissan if we all tell them we're having the problem. Isn't there a guy in this thread that works at a dealership? Give us some pointers here...I just want to get it addressed.

 

Well, I also own a 2007 and have not had the issue yet... I have been trying to be able to put a finger on it, to look for a problem, but the problem I'm having is that this condition is so rare and so hard to duplicate that nissan won't see it as an issue. There are no codes present (check engine light) and if a dealership cannot dulicate the concern, nissan won't research anything about it. You can always call Nissan Consumer Affairs, but they will ask you to bring a car to a dealership b4 calling them... Phone number is on the owners manual...

 

I'm going to take a stab at this. I do not own a 350 but I plan to get an 07+ 350 base so I am following this closely.

From my experience with the symptoms you guys are having, the only time I had this sputtering and power loss was on the track when I use to get fuel lock due to my baffle being to large.

Now I'm not saying it has anything to do with the baffle but I think this is a fuel delivery problem more so than type of oil/fuel is being used. And since people report that they are using quality oils with quality fuel and that plugs are fine then I doubt those are the problems.

This is just a guess, but I have heard that some OEM fuel lines in some cars (not necessarily Nissans) are low quality. Perhaps the new 350's fuel lines are low quality and too flexible.

At start up the lines are cold and perhaps the material shrinks and causes pinching in some areas. So the fuel hiccups pass the pinch but ultimately does get to the engine. After driving it a bit the lines open up and flow freely. If you stay at a certain RPM it hesitates/sputters maybe because at that RPM not enough pressure is going through the lines to open them up.

Just a guess. Another thing is, when my buddy built some race engines, he ordered AEM fuel rail. The AEM fuel rail fuel line inlet was not even drilled all the way through!! Fuel was barely getting into the fuel rails. So manufactures do make mistakes. Hell maybe the HR fuel rails are faulty?

Hope this gets resolved though.

 

^^^ good possibility

 

whatever it is, its a physical, mechanical issue because for those of us with aftermarket exhausts, we can hear the differance. The sound coming from the exhaust will sound normal then all of a sudden, the exhaust sounds more throatier while the issue happens, then goes away back to the normal sound..

damn nissan..

 

Yeah keep me posted, my Z sounds a bit rough for a engine with 2500 miles on it. I mean I hammer that ****ing thing but hey I did that with all my cars and my friend has done it with his Z and G. Yeah lets hope its something under warranty .

 

Adding on to my theory, it could possibly be a bad FPR as well? The argument of the ECU picking it up is semi-valid. If the FPR was built low quality the ECU is meant to read it that way so it won't through a CEL even if it was under-performing.

GodSendsDeath you drive an 08 and you think you may have this problem? That is not good since I was banking on the 08's to have fixed both the clutch and this problem.

 

My 2006 has just started doing this, one day it felt like the engine shut off at full throttle in first gear. It always does it between 2500-3000rpms at about the same throttle position. I am going to log it with my osiris and see what its doing but i suspect its the TPS or something related to it.

 

I've always kind of thought the TPS also.. let us know your results

 

If it is something to do with the fuel delivery, AAM's new fuel system and rail might be a good solution...

 

I have yet to see somebody w/ the issue where there is anything other then momentary and very hard to duplicate. when all the sensors are checked everything falls under the parameters.... this is going to be hard to find, really not looking forward to trying to solve this...

 

Mine has stopped doing it since I switched from Chevron gas to Shell. Go figure.

 

At one time, mine did it EVERY time you started it up after sitting for a while. You could probably have seen it happening without being in the car at all. Now, it's not nearly as often..and doesn't seem to be as "bad" when it does. I could kick myself for not getting it down there when it was really bad.

That being said, it's still not correct during that time.. it's flat and not running as smooth as the engine is capable of. The only real changes between then and now are colder temperatures, and more miles on the car.

 

i shall attempt this but not too hopeful.

 

also just a quick note, I'm not sure how much nissan is going to support us on this problem. I spoke with a very reputable dealership on this forum and even they were telling me that they might have a hardtime covering this fix under warrenty simply from the fact they cant figure out what it is and they can't just start replacing random parts by guessing. Please note, this doesnt mean they will NOT warrenty, but here is a sum up of the conversation.

I asked if Nissan would cover a rental car while i left my Z at their dealership for a few days so the techs could drive the car multiple times throughout several days. Basic response was Nissan MIGHT cover rental, but also might not. Reason being that EVEN IF the tech acknowledges the problem(meaning he know it exists), if they cannot diagnose what the exact problem is(which at this time doesnt seem like anyone can because the ECU isn't logging anything) Nissan will not cover this as warrenty work, hence the no reimbursment for rental car. I'm sure the dealerships wont charge us for checking out the problem, however, just don't expect any favors like rental reimbursment or compensation for anything.

 

I was told merely that the ecu wasn't throwing a code. Okay, I'm not sure that's the same thing as saying it is not logging anything.

Additionally, I'm pretty sure if they hook in a logging computer (of some kind) that they're going to see SOMETHING going on during these times.

As far as the rental, I couldn't care less ... I have another vehicle anyway. I'll try to be the guinea pig on this one... within the next couple of weeks. I'll get the slave cylinder upgrade at the same time.

 

Chevron is all I use every single time. I've maybe swayed outside of chevron 2-3 times in 10k miles. Not a single issue.. I'm running aftermarket HFCs and nismo exhaust.

 

goodluck! keep us updated. I'd do it but my Z is my daily driver. :-(

 

I thought they replaced the Slave Cylinder when you had the clutch issue..

 

They did, they replaced everything. I would assume however (being that mine was one of the first to actually get "fixed" that the slave cylinder is the same one that came out of it originally. I doubt seriously that I got the updated one.