Hey mate! :)

I didnt a CEL at first, but dealer was able to pull the code anyways, so maybe you can get that looked into anyways.


As far as mods, only the ones on my sig. However, i took all the parts out from my Z and its bone stock now and still have the issue.

This seems to be something bigger in my opinion, you have guys bone stock and mod cars with the same problem. One question, everyone with this issue has had a reflash done to their ECU? I know I did a reflash.

No reflash for me or carlitos

However, it does make sense that there might be some problems with the ECU. How can you have the failure now, turn off the car, and then have it working again like nothing happened? Doesnt make sense that dirty maf sensors and/or throttle bodies would do this! I would expect that if my mafs or throttle bodies are dirty, the issue will happen everytime i turn on the car, just like what i have experienced in other cars. Only thing i can think of is the "start cycle" or whatever its called. If this is the case then maybe it makes sense for this to happen. Ill have to start counting how many times it takes turning on the car and have this issue happen lol

Just wanted to chime in and report the same exact issue in my '13 z. Stillen gen 3 intake and fi exhaust. It goes back to normal after a few reboots :/ definitely feels like limp mode.

Damn... this maybe its a problem on the 2013 Z's... Well my friend i think this is the solution... The last thing that the dealer work on my car was cleaning the throttle bodies and re-calibrate them. I pick up my car las Friday and for the moment the car are working like new... Pedro leave his car on the dealer yesterday to do the same process. I hope that problem dont come again.... So get you car to the dealer and tell them to do the same process.... Clean the throttle bodies and re-calibrate them... maybe that is our issue.

Hope you can resolve this soon!!!

Check the brake switch if you haven't done so. I used to have the same issue. When accelerating briskly the car made no power after shifting into 4th... I held the pedal down, but the RPMs were dropping.

Update here:

http://www.the370z.com/nissan-370z-w...ml#post2937613

Thanks! Not sure if the dealer did this. However, i posted an update on what was done on 2 Z's here in PR with this issue. So far, so good.

Thanks. I plan to do this as well. Possibly later this fall.

Well, a quick update: two weeks issue free. Carlitos Z(who also had this problem), has also been issue free. Looks like the throttle body clean up and recalibration actually worked! Good to have my Z healthy again :driving:

Guess I'll have to clean mine...

True!!! 0 issue for now.. the car is running like new... fall in love again with my Z :p

Pedro & Carlitos, how are your cars these days? I finally cleaned my throttle bodies today. Took about 3hrs but i disconnected both and also operated the butterfly valves manually to ensure i removed as much carbon and gunk as i could. I already have the coolant hoses removed from both sides so that saved a lot of time and mess. I'm currently waiting for engine to cool down to perform the relearn procedure trifecta (first two must be done with coolant below 25c). Car felt no different after driving with the cleaned throttle bodies but the idle did hunt between 800-1200rpm - which is to be expected since i did disconnect both bodies and removed them from the engine bay for cleaning.

There wasnt a huge amount of gunk but most of it did require some rubbing several times with a cloth soaked in carby cleaner.

When i sprayed both throats, i noticed one held the fluid in a pool on the butterfly while the other dribbled out the other side fairly quickly. My first thought was that the one that doesnt leak is the least likely to be causing problems - sort of like if the throttle valve is at rest, it should be completely shut. After cleaning both thoroughly, i gave both a final blast down their throats and realised now BOTH dribbled freely out the other end!! So the carbon build up must've been so severe that it formed a seal between the butterfly and the wall of the throat, impairing the full range of the butterfly.

Both throttle bodies seemed to have a loose rattly sound when tapped on the black cover...

What is the mileage on your cars when this issue started?

I'll see how the relearns go in about 2hrs time.
Prior to cleaning throttle bodies, my idle kept sagging to 500rpm at the lights also.

:eek::eek::eek: it mustve been a lot of carbon then!!!

Well, so far both our cars are issue free after the throttle body clean up :happydance:

I had about 10K miles when the problem started, carlitos i think 20K (not really sure, but ill let him chime in if that wasnt his mileage). From what the dealer told me, they recommended to do the TB clean up once a year.

Good to hear you also did this, hoping this finally solves your issue since i know youve had this problem for a while. Keep us updated with results my friend!!!

i'd say once a year would be too frequent, maybe every 1.5-2 years if it's a daily. But that depends on how it's driven, oil choice (and whether or not a catch can is used), and heaps of other factors.

i did successfully perform the trifecta of relearns last night but now the throttle response/pedal response seems to have dulled. in gear acceleration isn't as jerky as before but i kinda liked the jerky pokey feeling whenever i tapped the pedal. i'll give it 1.5-2 weeks because that's how long it usually takes before the issue resurfaces after each attempt to resolve it.

so far i've replaced:
- both cam sensors
- gas pedal
- map sensor
- left VVT solenoid
- all VVT cover seals, 3 rings on each VVT cover and the gauze filter on each bank for VVT.

The VVT related parts did resolve the engine's lack of enthusiasm above 4000rpm, and that can still be felt today so i'm happy with that. The rest... i guess was all in vain.

Wooow! Youve definitely had it bad man :shakes head:

Believe me, im rooting for you to finally get this thing fixed! congrats on not quitting and selling/trading your Z because of all of this :tup:

mate, i'll be honest - i'm close to giving up. i've ventured into a lot of unchartered territory and despite all my hours of datalogging and troubleshooting, almost $1000 in parts and many up's and down's it's really frustrating to have the problem resurface within a fortnight.

it sucks being in a country where there are no Z specialists or Nissan specialists who are knowledgeable enough to know these cars inside and out. dont get me started on dealership staff attitudes... the lack of support here is beyond belief. they do anything to avoid dealing with the problem

And i thought i had it bad :shakes head:

Damn dude sorry to hear about the problem that your Z is having... well my Z like Pedro said... at the moment when the problem starts have around 20k miles. Saying that i see that you clean your throttles and a few things more. Well one of the things that i dont see that you do is calibrating them... Thats one of the things that i think that resolve our problems... Cause the mechanic that work my car in Service told me that one of the throttles open 100% and the other 50% or least causing that the car go into limp mode and not accelerate like they have to do. After they do that i dont have any issue on my Z... The price for that labor i think is arround $40-$60 for each one but i dont remember the correct price. Check that and let us know if that work ;)

oh, nah i just didnt mention the recalibration/relearns because it's assumed that the 3 relearns (gas pedal rest position, throttle body closed position and idle air volume) must be performed successfully if the gas pedal, throttle bodies or even the intakes are disconnected/replaced/renewed.

i took a big risk by disconnecting both throttle bodies from the harness AND manually opening the flap and jamming it open with a broom handle while i cleaned the carbon. luckily i didnt suffer the same fate as a lot of G37 owners where they were unable to successfully perform the idle air volume relearn procedure. my idle was high and fluctuating immediately after i reconnected everything (this was before i did the relearns, because the gas pedal & throttle body relearns can only be done on a cold engine with coolant temp below 25*c). the car still drove reasonably, SRM worked etc. The only thing wrong was the high idle.

Your mechanic's theory sounds logical. i think someone here also mentioned something similar, like both throttle bodies must be in perfect sync. I assume they mean the output voltage of the throttle position sensors must be identical. I have datalogged my TPS and they are within 0.02v of each other. I never noticed anything different in the logs leading up to a limpy lag episode so thats why i ruled out throttle bodies until now. I know on the R35 they can do a power balance procedure which basically syncs both banks, not sure if this is available in Consult3 for Z34.

Would you guys describe the issue as in the throttles refusing to open up or opening slowly but not at maximum even with the pedal to the floor? My engine doesn't scream in 2nd on up under 40 mph. However I notice if I floor it in 1st throttle seems to open up more in the later gears.

There was this one time I had trouble opening up the throttle. Then I heard a clunk and the engine and power surged while the pedal was nearly floored.

With my turbos it's harder to get it to spool up. When it does make some boost it feels like something is holding back power.

Damn bro sorry to hear about your issue... Well when I notice the problem on my Z, to accelerate the car from 0-50mph its a PITA the car literally do not run... 0 check engine lights... anyway on my case the mechanic change one of the MAF sensors and the problem still coming... the last things that they do was cleaning the throttles bodys and re-calibrate them... after they do that the car runs like new... if you car is having this same issue maybe that the way to fixed.... If not maybe try this one if you not already do it...

Considering that your Z have a TT kit installed check this things.... First of all i will do a boost leak test, check if the blow off valve its not open at idle, check the adjustment of all the clamps to see if one is not loosen.

I tell you this things cause my last car before the Z was an Sti... i have experience that after and my problem was the blow valve... I install a Tial Q blow off valve on my Sti and when the car was on idle the blow off valve a little bit open... i decide to change the blow off valve and the problem go... I hope this are not your issue but i recommend you that make the boost leak test first.

Let us know ok

Digi! i thought you resolved your issue with a new brake switch?
That is exactly what it feels like and what it looks like. i have a datalog which managed to capture a normal drive and the lead up to a lag episode, and the aftermath which was full on lag.

I have never got any CEL or DTC either. Which suggests the ECU might be at fault because anything which strays away from its command and expected response/result should cough up a DTC. But for it not to notice, a sensor must be reporting the malfunction as normal. I guess if overheating the oil can cause a limp mode effect without DTC, there might be other failsafe/protection modes which dont trigger a DTC. I have never experienced the full on oil temp related limp mode to be able to provide any insight on how the ECU restricts RPM and performance.

Anyway, back to your question. When it happens, the engine is literally choked and gasping for air. According to my logs, it recognises that the gas pedal is floored but the throttle plates are being restricted. It definitely feels like a commanded choking restriction rather than a dodgy TPS reading. What happens to me is the throttle position seems to be limited to max 20 degrees opening up til about 3500-4000rpm upwards, at which the car screams and takes off. But the throttle plate doesnt get to 20 degrees quickly. Just like you said, it takes an eternity. So when the lag hits, i really struggle to get the car off the line. Even a shitbox can accelerate away with minimal effort. Taking off uphill or with a full load requires some careful riding of the clutch and building momentum by holding the revs at 2200rpm then riding the clutch. by doing this, the throttle opens appropriately to match the revs. If this isnt done then the throttle position stays at whatever it is at idle, eventually opening more as the rpm eventually increases.
Merging into traffic, overtaking or even just turning at intersections can be damn dangerous, because you press the gas pedal like you normally do in the same circumstances and nothing happens. You become a sitting duck for the few seconds before you get thrown back when the engine screams to life.

When it happens, i also notice the VVT system change. The change in VVT and throttle plate behaviour are the only things that stand out consistently in all my logs taken during the lag episodes. Unfortunately, i havent been able to fully explore the potential VVT and VVEL system fault path because of lack of support. I really need some datalogs from other vehicles to compare with mine. The reason is because when the car behaves normally, the VVT system does not behave like it does in most other cars - Toyotas, or even in the R35 which has CVTCS also. So currently i have concluded that due to VVEL, VVT behaviour on our cars is different to that of non VVEL engines. Without other people's logs, i cannot go further with this avenue.

Without my Scangauge, i would've not been able to pick up instantly on the throttle restriction during these lag episodes.

I hope that helps in some way. Another thing id like to mention is that i took it to the dealer and they blamed my G3 intakes. I scoffed at them and i have not removed any of my mods. I have not de-modded because the car was running fine for a while with all these mods. However, after demonstrating the lag to the tech he disgruntledly took the car into the workshop and came back 5mins later to hand the car back to me. The issue didnt come back for about 2 weeks. You can imagine the heartbreak when it happened again...

Ever since then, i've been taking a few punts, chucked some money into replacing sensors without success. The one thing that i have noticed is that after performing what i have grown to call the trifecta of relearns (gas pedal rest position, throttle body rest position and idle air volume), the issue doesnt come back for about 1.5 weeks. For me, that's about a tank and a bit. I discovered this after i replaced the gas pedal and also after trying to resolving my sagging idle. I did the trifecta again after cleaning my throttle bodies last weekend so we'll see how it goes. Im getting tired of holding my breath

Yea I can see the throttle refusing to open enough causing the car to bog a bit at low RPM when getting in 1st and reverse. That definitely happens when things are too hot. Are the throttles refusing to open up because oil temps aren't warm enough? I notice this quite a bit when it's too cold or too warm, or after restarting. When it's just right (160-190F) I can get the car to open up.

At least one member talked about the ECU keeping the throttle from maxing out under 2k RPM. That's why I wonder why there's more power if I get on it or rev higher in 1st (versus taking of slow), then more throttle in the rest of the gears.

Could it be my driving habits? I'm pretty light on the throttle so I wonder if "eco-mode" has anything to do with it. All I know is when the foot is on the floor even at 4k RPM the throttle better be fully open, but it doesn't seem like it. But I do notice a difference in response if I floor it under 2k RPM versus above 3k RPM.

There's lots to do... just needing some time off to get around to dropping the bumper and doing some maintenance stuff.

Im having a similar problem as everyone. My car will be a terror on the streets in the morning and when first cranked up, then I will hit the gas and the lag is there. I can floor the car from 700 rpm and it takes a moment before it shoots up. The lag is between 700 rpm and 2500. I have an uprev tune on the car and I brought it back to the tuner for this issue. He took out some of the vvel magic that he did and it fixed the problem for a few months. All of a sudden the problem is back. He is sending me another tune and see if that helps. If not I have no idea whats going on. I started wondering if I was running a low compression on a cylinder but I dont think thats the issue. It seems to be a tune issue but now im wondering if its an sensor issue. Im going to keep an eye on this post.

Digi, that feeling of more accessible power if you rev out 1st is probably purely due to engine momentum.
there is a programmed throttle restriction, which yes can be tuned out.
im generally a pretty laid back cruiser too but getting off the line i generally go up to 3k max.

Mike, i think yours is probably just heatsoak related. but that's just a quick conclusion. The lag we are experiencing results in a several second delay in throttle response before the engine roars to life. what mods do you have?

I have the Stillen G3 intakes, CNT Res TP, Injen CBE, Stillen LW pulleys, Uprev tune, Z1 Plenum, Stillen grounding kit, Rods, Wiseco Pistons. The last 2 dont add any power and ive had for 60k miles. I have a stillen 25 row oil cooler to keep the engine cool and I have a Seibon BD hood to release all the heat. I can see the heat escape from the engine when I am stopped. Ive done everything to keep heat away. I had no problems with the first time I had my car tuned but when I went and got the Z1 plenum and retuned I started with the issues. I went back and got another dyno tune because the car had these issues. This helped for a while but then 3 weeks ago the car started acting up again. It might be a tune issue but Im not sure why the car would drive fine for 2 months before acting up again.

3 things that come to mind of whats going on...

1. Low compression, if so that sucks...I need to test
2. When the Plenum was done something was not done right with the Throttle Bodies or not put on tightly IE hoses.
3. The tune is too aggressive and it pulls the timing.

Well thats what is in my mind at least.

Tonight I am going to clean the MAF, throttle bodies, put on my other K&N Filters for the G3's, check wiring, reinstall the tune/unbolt battery, make sure all hoses are tight. I have the Z1 silicone hoses for my car and maybe I didnt tighten something??? I will let everyone know if I find anything. Im going to change the oil tomorrow as well in case it makes any difference ( i know it wont)

do you have an Uprev cable to datalog?
i think you're on the right track there. Did you disconnect the throttle bodies from the loom or bump the butterfly at any point? they are incredibly sensitive and i think there must be some sort of keep alive memory in them. They must be sapping a little power when everything's switched off to keep that memory alive. Otherwise i see no other reason why they seem to make the engine run weird after reconnecting WITHOUT performing the 3 relearns i mentioned above.

Did you do the 3 relearns after you fitted the plenum? (gas pedal and throttle rest position, and idle air relearn). the first two must be done on a bone cold engine (coolant temp below 25 deg celsius). the idle relearn has to be done after a decent drive, as long as coolant temp goes over 85*c i think should suffice.

Otherwise i'd suggest cleaning the throttle bodies and the butterfly valves, check condition of the seal between plastic plenum and metal manifold undernearh, and the seals betweem the throttle bodies and the plenum itseld. Do the 3 relearns after all is reassembled. You must use a stopwatch for the idle relearn because it's very sensitive to timing

Small update...I only had time to clean the MAF's last night. After using half a bottle of cleaner on them I cranked the car up and it immediately felt better. I have been driving around all day ant its running perfect. I will say that I am not counting my "chickens" yet as the weather is low humidity and 72 today. I will have to see what happens over the weekend. Fingers crossed at least. I'm still going to do all of the other things to make sure though.

Ugh. I've not had time and patience to work on my car, but hopefully it'll be something to do in December.

Anyhow, I've experienced limp mode for the first time yesterday afternoon in this cool weather. I was at the light when the engine died and all the warning indicators lit up. I started it back up, and it idled at 1k with the exhaust being louder than usual. I couldn't rev past 2.5k RPM. Whenever I shifted the RPMs dropped quick making it difficult to engage smoothly. S-Mode was still functional, and it could rev the engine past 2.5k. Pressing the pedal had no effect until the revs dipped below 2.5k. I was already nearing the gym so I parked my car and left it alone for a few minutes. When I got out to start it up again, it was fine.

What's interesting here is that there's no CEL, weather was around 70F, oil temps around 160-180F, and I was on a fresh tank of gas. This happened without warning other than the "lack" of power issue. Well it seems like the throttle is opening up more, and I'm able to get it to start boosting around 2k RPM. I currently have the boost controller dailed back to wastegate pressure of about 6 PSI. I was able to easily get it to hit 6 PSI at WOT in 2nd to 4k-5k RPM. Plus, it was easier to get boost at half throttle.

Who knows... I just need down time and several days worth of free time to pull stuff apart and get to cleaning. I'm seriously wondering of the crank angle sensor is on its way out as some owners experienced.

the crank sensor is one thing i have not changed. partly due to lack of availability and price. cam sensors did SFA for me.
its been a week since i did the throttle cleaning

After a full weekend of driving I am happy to say that my issues are fixed. I would say the first thing to try is spraying the MAF's. I wish everyone luck with there problems. Hopefully its an easy fix also.

cleaning the throttle bodies and performing the 3 relearns did not cure my random significant drop in throttle response. Like replacing all the VVT seals and o-rings, it cured a different annoying problem - sagging idle when stationary.
After cleaning and relearning, my idle throttle position is 0* according to my Scangauge 2 device. TPS voltage is about 0.55V according to Cipher. Before it would idle around 3*/0.6ish volts. So that tells me the throttle plate was probably held slightly open by carbon build up. So not a complete waste of effort. Glad to sign off on that one. I'll probably set myself a 1.5-2 year cleaning interval for the throttle bodies.

At this point, i have no choice but to delve deeper into the workings of the VVEL system to try and resolve this ongoing issue. With no local dealer support or technical experience, i am left to battle this alone. i might make a few phone calls to some Z workshops in the US to pick their brains

Sorry to hear that my friend :shakes head:

Keep us updated on this :tup:

hey guys, same thing is now happening to me (13 Nismo with 19k miles) it started 2 days ago and I remembered seeing this thread a while back.

so I figured I'd see what the dealer says

took it there today for the throttle problem and vibration during braking

this is what they found and are doing

-code for abs sensor
-warped rotors
http://tapatalk.imageshack.com/v2/14...7ccba02866.jpg

they ordered the sensors and should be here in 4 days, then when I come back to have them installed they are going to give me a courtesy car and do both the sensor and resurface front brakes free under warranty.

I know this will fix the vibration but I hope it fixes the throttle problem too and if not I they will fix whatever it is under warranty they say.

so I'll let u guys know what the outcome is after

on a side note I ordered some nice saikou michi dual catch cans

similar set up to this but all custom dimensions and black lines that I will tuck to look and keep everything more clean.
http://www.the370z.com/diy-section-d...cans-370z.html

also I'm still going to clean throttle body's and Intake Plenum either way

i hope they can fix that damn problem bro... trust me is a PITA :shakeshead: well my car after they fix the problem run like new today so. If they dont found the problem you can let them know what is the problem hahhaa!!

yeah hope it works but if not I'll point them in the right direction..
glad urs is running good now

Thanks bro!!! keep us updated ok :tup:

getting it done soon, got an appointment for tue at 11 then I'm getting a courtesy vehicle untill I pick it back up wed morning