Has anyone still been experiencing the problem? Weather has still been warm, and was having it until last Tuesday. I changed the oil, and haven't felt it since! I have 800+ miles on this oil (went on a trip), used the SAME oil (red line 5W30) and SAME filter (K&N, forget model). BUT I haven't had it... very interesting. That kind of sucks because I have an appointment with Nissan again on Friday with some tech specialist guy.

It has been cold, and I still feel the car holding back power under 3k RPM regardless of oil temperature. Mine barely hits 180F all day. The feeling is rough as I progressively press down the pedal.

I am still having the delay issue. Even if ambient temps are 40's and oil temp is 180 I still get the delay sometimes, but not all the time...which makes it suck that much more.

hasnt happened to me except for the one time i got the oil temp past 230. i wonder if we compare vins, if there is a certain stretch that has the issue?

Gas Pedal
 

Have you checked your fuel rail (injectors) or your fuel pump...if it was a Carb it almost sounds like vapor lock??:tiphat:

6spd -

I have read some of the things that you have experienced, and I live in South Florida as well. My oil temp is usually always between 210-220. I believe it takes some power away from the car because its so hot here. I believe Mike (the powdercoater), had an issue similar to this (losing power) and he ended up finding out that it was a problem with his brake indicator being on, so the ECU though the brake pedal was being depressed.

For example:
I was at a stoplight one time and there was an Audi TTS behind me. When the light turned green I let off the clutch like normal and then hit the gas. Started shifting through the gears but since it was so hot outside and my palms were sweaty, I ended up missing 3rd gear because my hand slipped (my shift knob is CF and it can get slippery when its really hot). But I quickly put it in 3rd gear, and I as did that the TTS got in the middle lane on my right, and he actually started pulling on me(We were right next to each other but he was slowly creeping forward). I know I missed a gear, but in the higher speeds that car should not be able to keep up with the Z. Afterwards I looked at my oil temps and they were around 220-230. So I've alwasy felt like the car was kind of "holding back" ever since I've had it. Maybe like Mike, its a brake ECU issue?? I want to find out but I don't want to ask Nissan lol. They might tell me my warranty will be void.

maybe, i dont know. maybe ill play with that one day, but as far as power goes, all cars are gonna lose some as temps go up, but what others are describing is worse than anything i ever feel, save the one time it happened to me above 230. :icon14: wierd.

I had the same problem and used masking tape and some paper as a shimmy. When testing it out my car screamed and spun tires. It was a totally different feeling. I took it in, but the tech said he couldn't move the brake switch any higher and suggested the shimmy solution.

How do I check fuel pressure and the fuel pump? I don't smell any gas and the car never has any hesitation or start up issues. I definitely have to rev it past 3k RPM to get the car going, but under that it feels like it wants to bog especially when I give it more gas.

Any DIY?

All the way back here:
http://www.the370z.com/700023-post137.html

Nevermind, it came back today.

I still experience it with the shim.

Ah yes you're probably right. BTW, my fuel sender went bad. On the next oil change I may have them replace it. Maybe they can inspect the hoses as one of the owners described some cracked plastic hose when removing and reinstalling the fuel pump.

Wha?! Can you give a little more detail... pic or something?

Oh I don't know anything about this stuff other than the fuel gauge not registering full when I fill up the tank. It's a bit offtopic at the moment until I get this issue resolved first.

OK, keep us posted!
I have my appointment tomorrow. Will let everyone know what happens.

Any new news on this. Would like there to be a known cause and/or a fix before I take my car to the dealer. Driving this car when this happens is very dangerous and this needs to be fixed.

Would love to hear what happened, IcedZ!

Sorry about that! Sometimes I just need a reminder...
Not much happened really. The guy came and drove my car for a while with me there. He brought Consult-II with him. He was not able to find anything "quantitatively" wrong, but he agreed there was something not exactly right. His initial reaction is that it is an ECU issue. Nothing came out of this visit. He said he will come back in January with some more equipment. He was very easy to work with and friendly. He gave me his cell phone #.
Hopefully more to come in January some time!
That being said, I highly recommend complaining about this and getting a special tech on your case. These techs are regional and they travel to different dealerships in regions to solve weird problems.

I have followed this thread for a while now, and the more I read I think it is a purposed design. I think that maybe in the same vein that Nissan wanted better MPG and henceforth did not include front brake ducts that would have decreased mileage due to drag, perhaps Nissan mapped the throttle in such a manner that if not fully depressed at launched at a high RPM, the car sips fuel below 3000 RPM. Further that with the torque curves seen in just about every dyno map done on a stock 370z, with a huge dip between 2500 and 3000 RPM, and the hesitation makes perfect sense - not that it does not suck.
It is ironic that a simple fix such as the gadget that increases voltage to the gas peddle is all that is needed to overcome some of the hesitation, but the inherent design of the engine and mappings make it fairly difficult (or at least some serious investments) to overcome.

Car and Driver Investigates Brake issue
Z Meets Wall: We Investigate Why the NISMO Z's Brakes Failed at Lightning Lap - Feature - Auto Reviews - Car and Driver

Agreed, there is an inherent lack of response... but again, there is a change in the car. It gets REALLY bad after some period of driving. I find that in-city driving make it much worse. I lose SO MUCH power that I feel like I will stall if I release below 1500RPM. But not all the time.

On another note, I finally got a chance to take my car to the track. It was EMBARRASSING. On the couple of runs that the car would cooperate, I made good times. But most of the time it was awful. I am seriously considering a new car (mustang?) now.
It was a beautiful day, barely hit 70. Could do 10 laps at MOST before hitting true limp mode (oil >260), and maybe 4 laps before semi-limp where speed is limited to 65(?)mph. The track is just shy of 1 mile. A couple times when oil was only ~235, the car REFUSED to respond. Just went completely dead. It was pitiful. I am very disappointed.

I get this too... in for an update? It feels like if i'm below 1500-2000 RPMs and I floor it the car tries to go forward, halts itself, then finally winds up. It's one of the reasons I want to get rid of the thing. It's unacceptable and annoying. My 350z didn't do that at all, I could launch it no problem.

The car can not be tracked successfully without an oil cooler even with cooler ambient temps. The water temp is always going to be around 190-210F and the water cooling the block is the only thing that indirectly cools the oil on these cars. Did you have traction control on? VDC kills all power if you try to accelerate coming off a corner.

Your problem sounds like a normal drive by wire issue...you have to gradually depress the gas pedal when you're that low in the rpm's. You're gonna experience the lag when you floor it.

:iagree:

NO, and NO.
Jeeze. If you aren't experiencing it, you don't know what we are referring to. YES, agreed... it's sluggish in that area of the power band. But it gets WORSE sometimes. It's tolerable normally. But sometimes it just acts up and it absolutely horrendous.

VDC was on first couple laps, then off. Didn't make a whole lot of difference.

yea... I understand that it would obviously take a small moment for the car to rev up from those low RPMs, but it seriously just stops, then goes. It feels as if the car is slipping on VDC or the clutch wasn't grabbing properly.

Like I said, my 350z didn't do that, my RSX didn't do that, none of my cars do that.

You can almost feel the ECU saying "HOLD ON THERE CHAMP" and cutting power, then suddenly letting up and allowing the car to rev up normally again.

Dude relax. I wasn't even referring to you. Maybe the guy wasn't explaining it clearly from my point of view. All I said was the way he described it sounded like it was DBW.
And FYI before you blow up, I have experienced the problem you are having only once(luckily)
I was driving up a hill and the car wouldn't give me any power, I didn't think I was going to make it up the hill.
So just take a frickin chill pill because we are all just trying to help each other here.
I wasn't even bashing the guy and calling him a dumba$$ or anything.

If this is a DBW issue, then it would be consistent from the start. The car is very responsive from the start after warming up the car. I can get the car rolling and floor it, and the car immediately revs up and overwhelms the tires.

After awhile, regardless of oil temps (even around 160-190 range), the car starts losing power below 3k band. Granted, torque is not as plentiful, but it feels artificially limited.

Anyhow, you don't need to floor it to feel the lack of power. You can give it 30-70% throttle while rolling in 1st or 2nd. The car initially revs up, but stalls around 2.5k before climbing past 3k and continuing regardless of throttle input. It feels like VDC cutting power. Now, while the car is "cutting power," I can literally go from 30% to 100% throttle in 1st and 2nd and it feels like I'm in the wrong gear.

Under this circumstance, and under casual acceleration, other cars are able to out accelerate me as the engine feels like it is struggling under 3k RPM even at 100% throttle and holding it down. Even with VDC off, the tires won't slip anymore from a roll.

I turn the car off and let it wait a few minutes, and the normal response comes back and I can start lighting up tires from a roll in 1st.

This is what I go through driving to and from work... not racing.

this pretty much sums up the experience of driving this car. this is constant for me and ive always chocked it up to DBW, because just about every DBW car i drive does the same thing, my moms TSX, my fiancees civic si, any of the newer cars i test drive at work... pretty much all of them. it makes it feel like a jerky take off. as far as the trouble as oil temps rise and loosing response, sure it happens to me, but not anything like some of these guys are describing.

so far we have decently conclusive evidence the following dont fix the problem being described:
1. oil coolers
2. reflashes/tunes
3. different engine oils
4. dealers
5. dealers
6. oh yeah... dealers

some have suggested the sprint booster thingy and swear by it... idk.

THIS. Exactly. Feels like I'm a gear or 2 too high. And same here, day to day driving.

Sorry, just very very frustrating. Dealer is no help. Nissan Consumer affairs is minimally helpful.

Didn't mean to sound like an a$$ in my last post, I just hit reply before I read it over.

No problem here after technosquare.

Maybe there is an issue with the VVEL servos not responding properly? Since VVEL does much of the throttle work at lower RPMs, shouldn't the VVEL assembly be the primary suspect?

Good point or ECU is too slow to process throttle position, fuel mapping, etc. before mechanically activating the VVEL.

Has anyone encountered this issue with VDC disabled? Even with it off, I think the car may still be in sort of a hand-holding mode....

Yep.. some of us (me) even pulled fuses. I also disconnected the Bosch yaw sensor one time.