Gas Pedal Delay

juld0zer

because the consensus blames 'high' oil temperatures. that sells oil coolers, which leads to a placebo effect in most cases (IMO).

External oil coolers are neccessary for earlier models which did not come with the oil to water heat exchanger fitted in 2011 and onwards models, and hot climate models. But on 2011 onwards models, it's overkill for street driving - even spirited street driving. It does a decent job at keeping oil temps under 100*c under most 'normal' operating conditions.

The other issue is the VVEL system. It's a very capable system and a pretty complicated system. I have never taken off the accordion pipes and ran the engine but i've heard it here a few times that the throttle bodies are wide open most of the time except under certain conditions, such as to build brake booster vacuum. The same folks reckon the ECU sends a pseudo-TPS signal thru the OBD2 system so for those who monitor via OBD2 you'll argue like me that the TPS suggests that the throttle bodies are NOT wide open most of the time.
Anyway, my point is that there's so much misunderstanding of VVEL - and also its oil requirements (temperature demands, for example). VVEL works fine even at 100*c oil temp in hot ambients. A more aggressive throttle map does wonders. But throttle mapping isn't easy and it's a bit of a trial and error experience sometimes.

There is definitely a delay in throttle response - i have seen it on logs. The ecu registers gas pedal input very quickly, but it opens the throttle bodies slowly and it does not open it as much as you expect. Likewise for VVEL activity. This is where an aggressive throttle map helps but doesn't eliminate the problem completely. Throttle mapping with VVEL is difficult because the tuner or yourself never has complete control over the translation of gas pedal input to throttle activity (ie. throttle bodies and VVEL). The ecu still has the final say.

What i have tried to learn in recent times is why the throttle response seems to become noticeably more sluggish when the motor is fully warmed up vs when it is still warming up or when it is cold. This is based on oil temperature, not coolant temp because we all know that coolant temps get hot very fast on modern engines to promote lower emissions.

If anyone wants to take the lead, i'd like to see what happens if you insulate the centre coolant pipe (the big one running underneath the actual metal intake manifold from the coolant filler neck to the rear of the head). Wrap it in exhaust wrap or throw some Earls fire shield over it. This is the final frontier when it comes to eliminating heatsoak because it's after the IAT sensor and the ECU doesnt know what happens in this area. But this assumes you have an insulated cold air intake system that doesn't get heatsoaked severely at a standstill - so the guinea pig will have to sacrifice some engine bay aesthetics in the name of science.

The other theory i have is that the VVEL motors are overheating and they get sluggish as they get hotter. But it should log a fault because the target angle isnt achieved - i guess that depends on how the ecu is programmed, in terms of how long does it give the actuators to respond.

Anyway, good luck My Z is for sale but it's been one awesome experience despite the lows. This is an awesome community of very knowledgeable people and it is the best car forum i have been a part of to date. The support, the experience, the info and guides - all make for a great Z ownership experience. I hope i have contributed and made a difference in somebody's Z experience but i'll still be around!

cab83_750

IMO, the Z-market is way too small (I.e., not much profit in it) for someone to invest the necessary R&D.

Jordo!

Can you show me that on a diagram or underhood pic -- I'll see if I can data log.

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Zed-Hed

Do we know if this condition is present in 2015 models.

juld0zer

Here's he part number for the pipe
21021JK20A

You can sort of see it if you follow the filler neck downwards and look towards the rear of the engine

Trilitheum

Your talking about this pipe correct?

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2011 Nissan 370Z Touring/Sport, 6MT, KAD

juld0zer

spot on! for anyone wrapping it, wrap the section near the VVEL motor also.

MagmaRed370z

I can say to the 2014 but I don't know about the 2015s.

FairladyZ40th

I have a guy who will get those cams to crack open in nano seconds pm me or email me I'll get y'all in touch here in San Diego! Migger93@hotmail.com


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birdman71

Cams no problem, although you needed to do your own coolant flush

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FairladyZ40th

Lol I did that freaking flush like 3-4 times too!!! Leave me alone XD hahahah


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FairladyZ40th

Ran into this, might be of help? Idk worth taking a look at, read the description

https://www.stillen.com/performance/...ssan-370z.html

"These grounding kits will also improve the shifting on automatic transmission vehicles, and in most cases noticeably improve shift times and reduce lag."


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tjlazer

That's not it, it's a known issue with some. Even on 6MT. It might be related to intake temps. When I start having this problem I have to launch at 3000 RPMs to avoid this issue, very frustrating!

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2009 370Z Monterey Blue,Nismo Conversion,RE-11's, K&N Typhoon intakes,Blue Kickplates,Homelink,FI 18" CBE,ERZ HFCs,Hotchkis sways, Swift Spec-R, EVO-R Highwing, UPREV

FairladyZ40th

Oh then in that case, a tubbing will help you millions with this issue but yeah I agree. The temp makes the car lag. I just simply suggest a good venting body kit i.e. Fenders bumper and hood haha. Blast your heater with the windows down


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ZeN

Gents, it is 33-38 degC plus humid all year long here in Malaysia, i've been having this trottle delay since my 1st day ownership. Have anyone tried use another IAT sensor which has the same resistance curve as OEM and relocate it to the mouth of the intake? It is embarrassingly slow to take off in any low gear when the rpm is around 1-3k, above that it scream all the way to redline. In a heavy traffic jam, IAT is always about 40-50 degC above cabin ambient temp reading, i logged all this with OBD2 and Nissan Datascan III app since the car is JDM. No issue with brake switch as i can see the value for both sensor switched. Idle timing was awfully low at about 3 compared to 9 when cold start. The only thing i've been wanting to check is the knock register and MAP sensor barometer volt value but theres no parameter of it in the Android app i have, no codes either. Maybe that was caused of the timing retard, had checked flexplate and theres no crack. Also have tried removing the MAP sensor driving with CEL codes and it didnt improve or making it worst. Happen on either full tank of fuel or low. Only good temporary solution that work only for short period of time ~15 mins is refuelling when near empty ~ 40 litre. Nissan tech had even datalog with consult III while me driving and cant find anything wrong.

Intake were all stock with addition of 36 row Z1 oil cooler and 25 row AT cooler to the sides. I really hopes we as a community get to solve this teething heatsoak issue. Car had 125000 KM already since i daily drive it to work since 2010. My next fault finding would be to replace MAP sensor and see if it is faulty. Envy you guys in colder climate country.