When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
i also have exactly the same issue with my 2012 g37s sedan 6mt.
I’ve noticed that sometimes i’ll be driving the car and it feels perfect - like the best car i’ve ever driven. Throttle is tight, car is responsive, and it feels like a precision tool.
Then other times, often even in the same driving session, i will experience the exact opposite conditions; the throttle lags, the car is sluggish, acceleration is non-existent, and the consistency is all over the place. Rev matching becomes near impossible. At an idle, one can hold the accelerator at full throttle and rev slowly up to 3k, where it will then blast to redline.
The revs hang, as well. You can quickly floor it and then let off the accelerator pedal, and the revs will hang constant, sometimes even continue rising slightly, and then slowly trickle back down to idle, where rpm usually hunts around a bit before settling on a normal-ish idle.
And then i’ll turn it on the next day and it’s perfect again.
Its like dr. Jekyll and mr. Hyde, and i’m so sick of it. I have tried stillen gen 3 intakes, a home-made grounding kit, inumerable ecm resets, throttle body cleaning, and tranny and diff oil change. Every single one of those things (minus the fluids) has a noticeable improvement on throttle response, but only when the throttle response is in happy mode.
I’ve also noticed that the issue seems to happen more when it’s hot out or after an extended bout of hard acceleration, making me think it could be somehow temperature related. I have new spark plugs on the way, but i doubt that will fix it. For the record, my car has had this issue since i purchased it with 35k miles (now at ~85k).
Ive got some videos i’ll try to find and post to demo the issue.
I got the problem solved when I got tuned by Seb at Specialty Z. As mentioned previously, he increased the line pressure to the transmission. Gear changes are quick and solid. The manual mode response lag has decreased as well. The 7AT time lag between pedal and downshift was solved with his pedal ratio adjuster custom input. It really wakes the car up. Downshifting lag is nonexistent but of course the gas pedal needs a lighter foot. I like it but others may not.
It's not the cheapest way of going about it but most certainly fixed it for me (along with k&n drop ins and free flowing exhaust). Well worth the money.
hey guys, so I've been looking into this problem quite a bit. You can also go on the 370z forums to find more info on this.
Anyways after cleaning the throttle bodies, changed spark plugs, cleaned mafs and pretty much everything else, somebody mentioned that it can be a faulty crankshaft positioned sensor. Somebody else mentioned a camshaft position sensor. Pretty much if any of these two fail, you feel a loss of power at low rpm and all sorts of other problems. Something to do with the variable valve timing or something which made it go retarded. You should look into how this part works, pretty cool imo. I got the CRANKSHAFT position sensor not the CAMSHAFT position sensor aftermarket from partsource ($120 bucks) and installed it myself. Make sure the exhaust is cold and it's kinda tricky to get in there. You need a 10m with a short extension and a flexible socket. There is a heat shield with a 10m which you can just loosen up and push down, and then there is another 10m to actually take out the CRANKSHAFT positioned sensor. Took it out, cleaned the edges (make sure no debris gets inside) and replaced it. The difference was night and day. Make sure to break it in nicely, so drive with respect, as these ladies deserve it. I hope this fixes my issue which was acting up under 3k rpms and what not. It felt like a 100hp 4 cylinder was running up until 3k rpms when a glorious trumpet would arise and sing its melody of the beautiful VQ engines. I really hope this helps.
Btw it did use to throw some codes but I kept deleting them. Eventually the car was acting up. Something about a bank 1 or 2 cant remember.
hey guys, so I've been looking into this problem quite a bit. You can also go on the 370z forums to find more info on this.
Anyways after cleaning the throttle bodies, changed spark plugs, cleaned mafs and pretty much everything else, somebody mentioned that it can be a faulty crankshaft positioned sensor. Somebody else mentioned a camshaft position sensor. Pretty much if any of these two fail, you feel a loss of power at low rpm and all sorts of other problems. Something to do with the variable valve timing or something which made it go retarded. You should look into how this part works, pretty cool imo. I got the CRANKSHAFT position sensor not the CAMSHAFT position sensor aftermarket from partsource ($120 bucks) and installed it myself. Make sure the exhaust is cold and it's kinda tricky to get in there. You need a 10m with a short extension and a flexible socket. There is a heat shield with a 10m which you can just loosen up and push down, and then there is another 10m to actually take out the CRANKSHAFT positioned sensor. Took it out, cleaned the edges (make sure no debris gets inside) and replaced it. The difference was night and day. Make sure to break it in nicely, so drive with respect, as these ladies deserve it. I hope this fixes my issue which was acting up under 3k rpms and what not. It felt like a 100hp 4 cylinder was running up until 3k rpms when a glorious trumpet would arise and sing its melody of the beautiful VQ engines. I really hope this helps.
Btw it did use to throw some codes but I kept deleting them. Eventually the car was acting up. Something about a bank 1 or 2 cant remember.
follow me on Instagram at: just_bness
Hey - I see you posted this a couple months ago (and I actually just PMed you as well). After a couple months, has this problem resumed for you or are you confident in saying that it's fixed now?
I know this is an old thread but I was literally disgusted with my 2010 g37x black coupe, I got not long ago. Got it this year with 50k miles on it. That's it and it's a 2010. One owner, no accidents. Babied it's entire life and taken to an Infinti dealer for service it's entire life every 3500 miles by the previous owner. They even did Tranny fluid flush , both differentials flushed and serviced, new this and that, etc etc, etc at 40k. It runs like butter and looks almost new besides slight wear and tear. Not one mod was done by the owner. Etc. Was a second car to a guy who had some money.
Anyway, point is, even with all that, the lag and lack of responsiveness at times was driving me crazy. I did a ton of ecu resets to no avail.
So I started changing things.
aFe pro drip in air filters
New post maf silicone tubes
Did a Motul engine clean oil flush
Added Redline 5w30 oil, which is all I'll use now.
TCU update
Did another ecu reset too
Then once a night I would run it like a bat out of hell.
All of these things helped but I still felt it wasn't lasting like it should. Some days would be off still. Mind you it was much better 80% of the time, even in 90 degree weather, and I've posted about it, but not completely there yet. I did realize you have to get a feel for this pedal btw. Once you do it helps immensely. Doenst always like to be floored and likes to be pushed towards the center. That also helped alot.
Next I did a couple fuel cleaners. Seafoam. Then I used Regan Gumout. Nothing. No changes.
Finnaly I tried Chevron Techron complete fuel system cleaner. The concentrated stuff. I swear to God once I poured this in and refilled the tank, 10-15 mins later it was a different car. I don't even believe in these cleaners so to say I was shocked is an understatement. This Techron stuff literally changed my car. I'm in frigging shock. I almost went back to our another in lol. But that wouldn't be healthy so soon. But that's how much it helped.
And now instead of driving it like a bat out of hell, I use it in manual mode and I don't go past 5th and try to drive around in 3-4th. And I'll make sure I do some aggressive downshifting as much as I can sometimes. That has helped and keeps me from having to push it hard every night.
So all I can say is this. Do one more ecu reset for a clean slate. Then use Chevron Techron immediately and use it corectly. Wait until your tank is almost empty. Put it in and then refill with 93 octane. Not 91. Then drive around in manuel most of the time for the first week. I swear on God's name it's night and day. Every time I drive my 37x I Hava. Smile on my face now.
I would also recommend Redline for your oil. Made a difference in how the engine ran. Idle and when driving. It's worth it. I recently explained how happy I was and was basically called a liar by another member because he couldn't fix his. Which is ridiculous. Well this was before the Chevron. Like I said I was still getting some off days. Well idk wtf was going on or how techron could solve my issues but it wss absolutely the last piece for me
I understand alot of the issues are the ecu. That's why you have to drive it in manual to teach it. However, some of the issues are not the ecu. They're issues that are adding onto the ecu issue and it definitely hurts it. I found doing these things eliminated those ones
Down the road I'm getting FI HFCS and their Catback and a Ecutek tune just to get the most out of it. But for now I'm veey hey content. I just got another compliment by a friend on the acceleration of this guy. When I first got it there's no way that would have happened. It feels light and zippy now.
BTW speaking of manual mode, I just want to say how much of a beast 4th gear is on this car. It's definitely the gear on this guy. All cars have a gear they love. It's absolutely 4th for my g37 x. I can tap it from any speed, at any moment, in 4th and the car jumps foward. I love it. Sometimes I wish I was always in 4th haha. 3rd isn't bad but too low to drive at higher speeds.
11-30-2018, 09:53 AM
