ZeN,
Please refer to my earlier posts. I detailed exactly what you propose on doing. I have done it before and it works, and later on after a lot of research i went several steps further to restore a more consistent driving experience.

In short, the 370Z really suffers from heatsoaked intake air temperature sensor. All intake systems are affected. All your observations mirror mine so there is nothing 'wrong' with your car. It is doing everything as it is programmed to do. There is a solution but it's not for those who love to show off their engine bays - although it's definitely a conversation starter. Goodluck & happy modding!

Lethargic
 

HI,

I have the same issues when it gets hot outside, my 370z turns into a Nissan Sentra.....Bogged down lethargic acceleration and laggy throttle response from idle up to about 3500RPM.

Did anyone come up with an ECU fix for this?

Has anyone approached Nissan to do a software update on the car or at least the ECU?

When i reflashed a different throttle map using Uprev, it cured it. Aside from the heatsoak issues but you need to determine which you have - heatsoak lag or the actual unrelated lag for no reason

I have this and it made a huge difference. Throttle response is now linear. While this can be fixed in a tune, using this makes adjustability much easier so I plan to keep mine even after I get it tuned

I thought the same thing until I actually had my car tuned. I turned it on once afterwards and felt it was useless at that point so about to sell it.

Is there anyway that an UPREV tune can address this throttle response when IAT temps are higher?

Uprev
 

Thanks guys for the info...


How can I get my hands on this Uprev ECU reflash?.....Mine is Heatsoak I believe.

You cant do anything tuning-wise to reduce the impact of heatsoak. The only solution is to address the heatsoak problem - insulate, reflect and relocate. Heatsoak is inevitable. You goal is to delay its onset.

After so many years since i left the platform i am amazed Nissan has not done anything to fix the problem. But you guys as owners need to determine whether there is truly a bug in the ECU software or whether it is simply lag due to pulled timing due to high IAT (actual or false due to heatsoak). For me, in the end it seemed most like a bug in the throttle map or the way the ECU processes input from the gas pedal to output to the twin throttle bodies. It is a complicated system with VVEL, two throttle bodies, and having to manage brake booster vacuum also.

The best way to describe what is happening is the ECU thinks there is a problem with the throttle control so to prevent uncontrolled acceleration, it puts the motor into limp mode without illuminating the CEL. Acceleration up to 3500rpm will be extremely poor and scary when pulling out of junctions. Just like limp mode. Restart the motor and it clears. Leaves no trace.

Those of you with Uprev, i strongly suggest loading a new throttle map and test it out. I wished i still had my Z to continue this witch hunt for you guys but good on you all for sticking to what is an awesome bang for buck car. These days i drive an E82 135i which longs to handle like a Z haha

This is definitely limp mode. I was having similar issues when I went to 3" MAF housings. Check to make sure there aren't any soft codes sitting in the background on your ECU. I've experienced limp mode multiple times with no CEL but the soft code was present in the background when I scanned it. Sometimes those soft codes can come and go if the problem is intermittent so scan the car often and maybe you can catch it. FYI between 2009 and 2014 Nissan used a P006A code (MAF/MAP to throttle position correlation) which came up often, even on factory stock cars. In later ROMs Nissan removed it because it was too problematic.

Side note: the wstar's 2300 throttle map is pretty good. That's what I'm running currently.. could be a bit more aggressive at lower RPMs But it does get the TBs open much quicker than stock and is stable over all

Hello everyone, I guess for documenting purposes and to find out what else have folks discovered in the 4 years that have passed since this.

I have gathered that one way to help with this delay is a tune, the other delay has to do with heat soak of the IAT. Lastly for those boosted, issues with the booster MAP.

Throttle pedal commanders seem not be as efficient after a tune.

I have adjustable throttle response with my ecutek tune

Not sure if I’m on to something or not, but I was having issues with a P0300 code for a long time and finally got that resolved by cleaning my MAF’s. Haven’t had any gas pedal issues since.

Wow. This thread was a damn good read. All the way from the 1st page. Only reason I'm here is because of that dreaded gas pedal delay and laggy throttle response. Heat soak and IAT sounds like a logical cause. The reason I'm sure is because throttle response during warm up from cold start is nice and crisp as many have stated already. But once that oil temps warm up you can definitely feel a decline in throttle response at low rev ranges below 3k vs what your input is with the gas pedal.

That one video that showed the behaviour of the revs with quick slamming of the pedal vs gradual smooth input is really telling. That rev hanging under acceleration is also interesting which is exactly what I experience when the engine is hot either from DD'ing or a little spirited driving with the gas pedal delay. I'm hoping someone here can explain this phenomenon with the VQ37.

One thing that hasn't been touched much over the 50+ pages of this thread is if running lean or excessively lean, or a hidden vacuum leak would cause poor throttle response due to the ECU retarding the timing for VVEL to protect further engine damage. I know watching the behaviours of short trim fuels is a good way to tell if you're running too lean or too rich.

But basically the current solution is:
1. Get a tune with improved throttle maps
2. Isolate heatsoak
3. Somehow retrofit more fans to improve cooling (no idea if anyone has done this)
4. Install and keep throttle controllers (sprintbooster) for the added placebo effect

Unless some tuners have found the golden ticket to finally eliminating this problem. I would really like to know. Many Z owners would benefit from this.

After reading this monster of a thread my conclusion would be to just get a tune and install sprintbooster incase it is needed for really hot ambient temp days. And see how it goes from there. Might look into some heat soak solutions later on too.

It's a shame the VQ37VHR doesn't have better heat management systems. Otherwise this v6 would be amazing.

Best of luck to you!

If you have a tune, it is truly a waste of money to also install a throttle controller (sprint booster). Just program the throttle maps in the tune to exactly what you want. The tune can program 100% throttle at 10% pedal if you so desired. Don't do that but just realize the sprint booster increases voltage which can simply be replicated exactly in the tune via programming. You can program different tune maps same as the sprint booster has different modes.