No power below 3k
 

2009 Manual Sport with 94k

New problem for the car, has severe power loss below 3k. No matter how hard I step on the pedal it just doesn't accelerate much but then when I get to 3k or above it pulls fine.

Car has Z1 oil cooler,, KNN drop ins, test pipes, Nvidia Gemini cat back, and LW Flywheel.

Replaced the MAFS, no change.

Looking at torque app via OBD2 scanner it shows an anomaly with TPS, it doesn't seem to go beyond 10% throttle input until after 3k and only registers a max of 90% in the high RPM range.... BUT I know from other cars the Torque app always has weird TPS readings so I am not sure I should trust it.

Happens regardless of oil temps, IAT, Ambient air temp...

Here is a video of me attempting to demonstrate the issue. It might not be very obvious in the video but trust me it is incredibly noticeable it feels like someone stuffed giant potatoes in the exhaust until 3.2k or so and was never like this the last 10k miles of owning the car.

Any help would be appreciated, thanks guys. https://www.youtube.com/watch?v=7xVcbeeHWaE

Sounds like your car is going into a "limp mode". Happened to me a bunch of times while getting initial tunes. It's the ECU trying to protect the engine. Something definitely fishy. Any upgrades lately?

Not even close

TPS=THROTTLE POSITION SENSOR?

Perhaps dirty Thorttle body/sticky and ALSO try a Throttle body re-learn ( TP open, closed and idle air)

Symptoms sounds like such.

FSM section EC-20 to EC-22. ( if you have FSM)

Did you recently do any work on engine? Any codes?

What's a code reader say?

Mine did that and I replaced both throttle bodies.

Thanks for the replies guys.

So no recent work to it outside of an oil change about 2000 miles ago.

No codes at all and all monitors are set.

The odd thing is it only happens intermittently, but happens far more often than not.

At this point I think I will at first attempt to clean the throttle bodies, and then possibly replace them because part of me thinks it is in fact throttle related. Only having a crappy 5 dollar OBD2 bluetooth dongle and the Torque app makes diagnosing real time kinda difficult.

I'll update over the weekend once I get them cleaned.

I would really suggest doing the relearn after cleaning. There are multiple checks you can do to confirm throttle servos are failed. You need the FSM and should be available from someone here. You can save money and maybe isolate something else.

Parts stores can get codes for you for free. I understand time may be a factor for you.

good luck and keep us informed.

zz

Any update on this? Mine does this randomly. honestly it feels like it's pulling timing until 3k and then launches.
I'll be taking mine into the dealer for a service appointment on Monday and I'll have then install the lastest/newest Engine management software to see if that's the issue.

Yes actually!

I cleaned the throttle bodies, replaced my intake tubes with some Z1 silicone tubes, replaced my PCV hoses with some Z1 silicone hoses, as well as cleaned my K&N drop in filters really good. Then did all the throttle body calibration steps I found online.

So far the issue has yet to come back... BUT unfortunately the driving conditions are also different so it's not exactly apples to apples. When I was having the issue the days were 100+ degrees, and now since doing the work they are 75-85 degrees.. so that might have an affect on my testing unfortunately.

Keep us posted on your results with the dealer I am very curious.

I've done similar cleaning, the only thing I haven't done yet is the throttle body relearn/calibrations

From what I've researched the ECU will pull timing if the oil temps start getting above 200 degrees, and/or the intake air temps get too high (not sure about the limit on that), however I have an oil cooler and cold air intakes, so I doubt that's it.

I should add that mine is also an '09

I'll keep you guys updated after the appointment....unless I forget :icon14:

Don't over oil the K&N's. The extra oil from the filters will find it's way too the MAF's and beyond.

Quick little update, the car is at the dealership, asked them to flash the newest Engine management.

I'll report back when I get it back in a few days and test it out

Sounds like "you should get a custom tune" kind of issue, the stock tune is very ...let's say hybrid up until 3.2k, this is normal, it is most felt usually after driving normal and then flooring it from a stop, the car re-learns to be a bit agressive or hybrid depending on the driver accel input, but all of this is even more noticible if you modified the intake and the exhaust, at this point you need a custom tune to get your car accelerating right.

I doubt the ECU update is going to do jack for you. The changes are not performance related. More like maintenance to keep up with newer technology from what I've heard. Report back and let us know.

The custom tune will definitely take care of the issue, however I'm just not done modding the car yet, once I finish that it'll go in for a tune

A few years ago I read an article that stated Nissan for, I believe the 2018 year model, improved the throttled response and remapped it, though I can't seem to find that article.

Currently on my way to pick the car up today


Edit: found the article
https://usa.nissannews.com/en-US/rel...upe-press-kit#
Also in 2018, the 370Z driving experience was enhanced through optimized acceleration and torque profile tuning. Without changing the engine's internal structure or components, engine performance was improved through careful refinement of Accelerator Pedal Opening (APO) and Throttle Valve Opening (TVO) angles. Manual transmission-equipped 370Z models added a motorsports-inspired EXEDY® high-performance clutch."
"

Whoa that is very interesting... yes please update us on how it goes - if I can go in and get a flash real quick that would be great. Dumb question but is the service free or do they charge to flash the ECU? At that point I would probably just hold out until I am ready to get it tuned.

I've driven an 18+ model before. The throttle response and torque is not noticeably different than previous year models. That is to say, the stock tune is still garbage. Because there are people that don't like their sports cars to respond quickly, so Nissan has to numb the shìt out of the car's potential responsiveness.

Update
 

The hesitation isn't as bad as it once was before, however it's still there, the "retune" made it a bit snappier.
As for the cost, it was free, they just added it in to the work they were already doing.

Would I recommend it? Eh, not really unless it's free or you don't plan on custom tuning it in the future

Edit: fixed typos