My '08 does that during the first several seconds after a cold start. The initial speed is around 1700 rpm, then it sputters several times as the speed drops to 1500, followed by a jump back up to smooth running at 1700. From there it gradually drops down while continuing to run perfectly smooth.

Based on that, I'd say the ECU is trying to find the leanest fuel mixture that'll allow the engine to run without misfiring. If mine does it any other time, it's certainly not noticeable.

 

I'll give it a shot and Datalog it with Osiris and post up my findings.

 

cool...check the timing/fuel trims if ya can....i know most people are looking at the o2 sensors and seeing the result of what the computer is doing....

almost everytime its one side of the motor acting up.........


when its one side of the motor, it narrows it down to sets of sensors that monitor both sides....MAFs....TPMS/throttle body.....o2 sensor.....camshaft sensors....camshaft solenoid.....you get the idea

 

not the same problem.

 

Had a very brief conversation with a Nissan master tech today. He said it could be something related to the throttle switch since the "problem" occurs right around 1700 RPM. Just thought I'd throw that out there.

 

Started to happen to me recently on cold starts and when lightly touching the gas while driving, I would get some cut-out. I now make sure that the car is fully warmed before taking off from a cold start and it hasn't happened since. (crossing my fingers)

 

well my car does it EVERY single time during warm up driving now, awesome lol

 

damn there is a stickey for this now . . hell yeah . . ok . . soo i posted this in the maintenance sections (wrong place)
https://my350z.com/forum/maintenance...when-cold.html

ok soo the above thread was going in the "HR Z clutch is bad " direction . . . .

 

anyways let me repeat my story

* Got the car 07 Enthusiast HR stock at 30k . . . drove it at the dealership . . it was doing the cut- rev - cut- rev thing when cold . . i though this was just me not knowing how to drive . . . . . loved it bought it . . and drove it back home 200 miles . . . it drove as if it was running on whipped cream . . i was soo happy

* Noticed the cut-rev- cut - rev around 1.7k - 3k rev range for the first quarter miles of driving in the apartment community entry /exit that i stay even after 2 mins of idle warmup but after that it runs perfectly fine

* changed transmission and diff fluid - issue still existed

* changed air filter with clean paper filters - issue still existed

* changed filters with k&n drop ins - issue still existed but was somewhat better

* changed oil from synthetic blend to fully synthetic (valvoline 5w30) - issue still existed

* so far ran the car with only Chevron 93 and also put in a can of techron concentrate and drove for 2.5 k miles - issue still existed

* changed oil to mobil1 5w30 - issue still existed

* got Berk HFC - issue still existed

thinking of getting the battery checked and get a grounding kit . .

if that dosent help ill get an exhaust and get a tune done . . . . .

 

well today i have her up on four jack stands....im going to get a close look at the headers and gaskets to see if there is an exhaust leak that far up. all the impacts on my exhaust from being lowered has to of had some adverse side effects on the manifolds

im telling myself "its got to be the issue"

 

found the issue everyone. And your not gonna like it.

headgaskets




explains ALL of my symptoms now. I never even dreamed that this could be it because its a 50k mile 07 vehicle. stock everything is going back on and after warranty its getting sold

 

ok . . im new to this but . . . if the head gaskets are bad how is it that the issue disappears after proper warmup ? and happens only under load . . ? ? . . assuming your theory and my symtoms are related . . dosent this mean a recalll for Nissan ? ?
btw i dont get any codes or anything . .it just jerks as if its on the wrong gear under load just after warmup and . . if you give it power it just goes . . .

 

OHhhhhhhhh Nissan is going to be Pissed lol.

 

A slightly more in-depth description of your diagnosis would be helpful. From my experience, a leaky head gasket causes a lot more problems than bouncing revs during warm up.

Are you sure your problem is the same as everyone elses? I'm hoping that it is, because my car just went out of warranty. Guess I'll be calling Nissan and getting an extended one.

 

Also, I went to my local Nissan dealership (Texas Nissan Grapevine,TX) on Saturday. I spoke with their most experienced tecnhician, who could not nail down the issue either.

He said that any of the ideas mentioned including, wrong oil, oil screwing up vaccum and sensors, faulty sensors, clutch issues, fuel issues, etc., could potenitially cause the bouncing or sputtering issue. However, he felt it most likely has something to do with our clutches wearing unevenly. The HR's history of problems with the CSC also pushes me in this direction.

He also mentioned one other option, a sticking thermostat.

What do you guys think?

 

ok my bad . . it has nothing to do with load . . . today it happened to me again at a stop light . . . with the clutch engaged . It happened at 1900-2k . . almost felt like a rev limiter at 2k. Now im beginning to strongly believe that its a software glitch.

 

it can't be the clutch, that for a fact is out the window I have about 5K Miles on my new set up. (Clutch, Flywheel, and Billet CSC) so that is not the issue. I personally think its something with the ECU Self Learn Program. reason being is that when i first Had my Car Dyno Tuned, the problem was not there at all I thought it was fixed, but it slowly came back, and now it happens to me every single time during warm up.

 

any luck with resetting ECU ? i dont mind resetting the ECU every 2 weeks if i have to . . .

 

So i been seeing 2 different problems happen and cant tell which one this thread is for or it both. 1. acc. and it feels like vdc is coming on 2. turning car on after a night of being off/cold and car goes to 1,500 rpms and sputters, almost as if it going to die on you. If it for the last that what i have had done. changed spark plugs, leak test, maf sensors clean, and have taken to uprev which they couldnt reproduce it unless with a over night stay :/.

Funny thing i never had this problem what so ever till this march when i got my final tune(added intakes and y-pipe) and changed oil. Then about a month later i start getting it. Even on the stock nissan map.

 

Same issue on mine it seems...

The mechanic thinked about dirty body throttles, cleaned them, but the problem still there.

I also notice the following issue, don't know if there a link...

https://my350z.com/forum/vq35hr/5010...ml#post8671229

And no DTC !

Don't know what to do... Change O2 sensors, spark-plugs...

And, happy to read that thread as everyone think I'm fool !