That's the reason I got rid of mine. It was a major safety concern. Scared the hell out of me twice.

I got a 2011 Juke, and I thought that alleviated my problem; but I feel like it does something similar sometimes. It's an automatic though, so it feels different. And it's a small turbo engine.

Interesting enough, a buddy was selling his sprint booster from his already sold 370z. So I inquired into it and letting him hook it into my car so I can try, and WOW what a difference. I definently thought this thing was a scam, but its working great so far. I guess my issue though is that this seems to be like a bandaid on the problem. Im still very anxious to know if an osiris tuner can fix this issue 100%. Im willing to pay for the tune JUST to fix this issue with my car if the tuner can guarentee 100% it can be done. I just want it fixed otherwise im gonna haveto sell the Z. I cant be worried about driving around town and dying at traffic lights.

I haven't had this happen to me in quite a while, but it's definitely a shocking experience when it happens the first couple of times. Just don't throw it into 2nd too early or be in 2nd when turning onto a main street(e.g. exiting a gas station or mini mall) because it's going to lag. I never engage 2nd until I'm well passed 3k. And FYI I've been shifting at 4k and my average mpg went form 21 to 22.7 =) so that's another plus!

Wait another month when it starts getting warmer. You'll get it back.

I've had the car since it came out and I've always hovered around 21mpg. Nothing has changed, same route to work and home and same daily usage. And it wasn't until recently I decided to drive the car a little harder because I've babied it for so many years. And surprisingly, the car gets better mpg shifting at 4k :icon17:

I've still never had it happen. It was in the 90s all summer last year. I don't drive slow, either. :confused:

Never happens in manual mode, but auto mode is another story. And it gets worse in extreme temps. Hot or cold. I drive 90% in manual mode so it doesn't bother much. But I might get sprint booster for days I need to be in auto mode.

Posted this problem in this link:

http://www.the370z.com/engine-drivet...irst-gear.html

I can't believe that NONE of the tuners have figured this out yet. My 2001 Porsche Twin Turbo has drive by wire, and I don't get any of this ridiculous lag...

I've experienced this issue a few times.. feels really awkward, but only happens in auto mode. I hope It gets fixed with the tune.

Normally happens when you step the gas right after it has shift to 4th or 5th gear

Reported

in the "bogging in 1st gear" thread, a poster mentioned the the etc can be turned off at the expense of losing your cruise control. he stated that when etc is turned off the ecu will keep a one to one relationship between the throttle position and the throttle plate. anyone tried this, if so was the throttle way too touchy as stated in the other thread? I was thinking of try to get a tuner to make a non etc map to try it out.

edit: non etc meaning the the ecu will not try to close the throttle to limit torque. seems like this system is programmed to be way too intrusive from the factory.

IIRC, member "wstar" did this. IIRC, it disables S-Mode throttle blipping and VDC as well.

But yea, there has to be some sort of aggressive torque management going on. I read about Camaro owners having the same problem.

Its the drive by wire system.. And the fact that your increasing your gas and engine load enormously. Its going to take some time.

The 350z is also drive by wire and doesn't have this issue. It goes beyond the system. It's also obvious that it's temp related.

Last report I got from UpRev is that they still have not cracked this issue with the ECU. It has to do with the variable valve xxxx and that is the difference between the 350Z and 370Z.

that's kinda weird, didn't the revup (exhaust side only) and HR have VVEL?

: /

VVEL is not the same as CVTC. VVEL is computer controlled intake valve lift and duration for throttle control instead of the traditional butterfly.

^ :iagree: what he said

I had this issue with mine and mostly when trying to get accelerate from dead stop making right or left turn. I agree that it is pretty scary as you would think that you can merge into traffic safely...and then the car just sits there like a lame duck.

Oh yes, warm weather definitely affects the car's performance. I wasn't able to do anything with the 'lame duck acceleration' but I added a cooler and IMO fixed 80%+ of the issue.

25 row oil cooler and issue still occurs 100% on hot days.

had no clue about that. thanks for explaining :)

before i go waste money on long pcv hoses(for a little more cooling effect),do you think that this delay is related to too much heat being dumped in the intake manifold from the pcv's ?

I would love to see someone solve this I cause cant stand it,, I have a AC and if I jam the pedal to the floor car just sits there then goes, Fun cause it feels faster off the line if I jab it like 50% till it ramps up them floor it?

im definitely going to try some experimenting with trying to keep the im as cool as possible including putting in some heat shielding from on top of the engine to block as much heat as i can.maybe its a safety measure to keep the plastic i m from melting ? if i drive normal,i dont feel this symptom.but a couple of spirited hot rodding runs takes a toll rather quick.

As "wstar" stated, throttle opening is limited at low RPM. That's the annoying feeling. I can't wait to get a new tune with updated throttle tables.

you sure that will make a difference? I have mine set at 95% open I still have a it, I actual think it has something to do with the throtlle position sensor and not the tables. For some reason it doesnt pick up you STOMPED on it for like 2 secs?

i had this problem b4, uprev solved it 90% it still not INSTANTLY but not noticeable. also the shift lag in the auto also disappeared. done at zcar garage

what i thought was related to pedal delay was in fact related to the oil that the dealer had in it when i bought it.put penzoil platinum in it tonight and what a difference it made in pick up and oil temp.

^ second that. i use PP too and definitely notice a difference after yesterday's oil change. after TP's, UPREV was the best $500 went from huge hesitation to sporty throttle response. Also re-flashed ECU (same tuned ROM) that made a difference too.

Really? That stinks. My tables are still stock other than the turbo tune. I just hate the sudden surge in 1st gear.

This happend to me on my old 350z. Throttle problem...

I believe this was mentioned in this thread, but I can't find it. Maybe it has to do with Octane? I am considering buying a BRZ / FR-S (Juke just isn't quite sporty enough - and I hate front wheel drive). I have been reading some interesting threads on it where people in some states cannot even purchase >91 Octane gasoline. The manual recommends 93+. 91 will not void warranty, but some people are saying stuff about the car being a little lethargic. Has anyone put octane booster or racing fuel into their car? I would LOVE to get another 370, but refuse until this issue is identified. Good luck to all of you with with issue.

Honestly, I can not tell ANY difference between 91 and 93 octane as both are available here. I used to use an octane booster in my 94 Firebird Formula when I went to the drag races and I really didn't feel any difference either. I know some pumps in the area carry racing fuel (102-104 octance) but at the prices that they charge, I'll keep using my 91 or 93.

I haven't experienced this yet, but I am also not home during the summers anymore (not by choice). I was reading though all the post and very well could have missed it, but were people who have vented hoods having this problem? I was reading a bunch of different post about hood vents and saw one from modshack about removing the hood gasket above the firewall and how that has helped in the past with heat, if heat is one of the potential causes of this.

I know what you're saying, but I'm just wondering if maybe ethanol content has to do with it, or maybe 93 gas isn't as pure as it should be?

Octane in my opinion has nothing to with it. I have used 93 since the day I bought it and it's consistently there everyday. Do people with gtm supercharges and tt kits have this hesitation? I'm just wondering with the FI tune and the added power if you can feel these hesitation issues.

Sprint Booster doesn't really fix anything. It's more of a psychology fix: it changes the gas pedal input sensor to react as if you'd pushed the pedal down further before you've actually done so. You could get the same effect by just changing your pedal habits.

http://www.the370z.com/tuning/43384-...tle-uprev.html <- this has my throttle map and the stock one to compare to, and various other bits of data on the subject. There are definitely aspects of this problem that can't be solved through the throttle map either, but this helps (and smooths out the response curve for predictability rather than mucking it up and making it jerky).

Yup... looking forward to making these changes once my car gets a proper tune.

A lot of this may be heat soak. When it is hot out and the car has been running a while everything under the hood is super hot including the air boxes there is no ventilation in the engine bay and it acts like a a huge convection oven.

When leaving work for the day my cars both the 370z and the Nismo are parked in a garage staying nice a cool. When I first leave the cars are very responsive and throttle reaction time is quick and brisk. Once I have been driving for 20-30 miles it start to slow down on acceleration even though my oil temps are 200 degrees. At a light if I am sitting for two minutes when I press the gas it just sit barely moving until I get to about 10-15 mph then it kicks back in. This is heat soak. If you have a decent OBDII scanner you can watch your intake temps. They will be soaring at idle at the light so when you accelerate you get the bog. Once moving again they cool to ambient.

Having a tru CAI will eliminate this problem. Short rams won't do it, a lot of the kits I have seen won't work. You need a way to bring in cold air as close to the ground as possible preferably taking in air from the front away from any heated part.

You also want the tubes inside insulated from the heat of the motor. The way they designed the two TB intakes on either side of the mother just over the manifolds is to say the least retarded! The problem of heat is compounded.

The corvette, and other sports cars the TB intake in in the front of the motor away from the heat of the manifolds. The intake has a short run from the front of the motor to the TB so intake temps will stay lower. An intake design change of the 370z motor moving the TBs to the front away from the heat of the manifolds would add a lot more performance.

The best solution is to find a way to let heat out of the engine bay. I know my 5.4 in my Expedtion does no put off half the heat the 370z does. I pull into the garage and it will heat up my house so much heat is pouring out and it stays that way it won't cool,down for hours. I habe to leave the hood up. It even heats my house nice for winter , but summer no! I don know on this maybe vents in the hood or side something to vent that heat out.

The bog is purely heat soak though.

i have counter acted this problem 90%.throttle body bypasses on this car are a must !!.removing the rubber seal under neath on the front of the hood will allow air to get in there.just ask the bugs that i now collect on top of my air boxes.i have drop in filters and post maf tubes.i still didnt feel there was enough air getting to my filters in the stock box.so i opened the outer corners and removed the rubber that goes over the angled outer radiator supports.

i also copied another members idea on here that modified the front half of the engine cover for his catch can hose connections.doing this will also aid in heat escape from the pcv hoses not being able to add additional heat onto the im via engine cover.i bought the car used and i have made the car way more efficient by doing what i did.the computer on the car said i was getting 18.2 miles to the gallon when i bought it.

i now get or average 23 miles to the gallon in city driving shifting at 4-5k.take it for what its worth.i will add a pic for your reference.love it or hate it,these mods work well for me.air boxes still look stock when you pop the hood.also while its just a theory,i think the 02 sensors start messing with the fueling after they get so hot from this engine.i will add spacers to the stock setup sooner or later to test my theory.

EDIT;also in the 2nd pic,i have added cell foam pipe wrap on the maf tubes to aid in heat protection from the engine at idle.and when i can figure out where to put 2 catch cans on this car while keeping the oem air boxes,i will do that also.i know from experience on another car that besides the cans catching oil,they will also provide a little more cooler air going into the im.just dont know where i can mount a couple of small cans.

http://www.the370z.com/members/kenny...-satisfied.jpg
http://www.the370z.com/members/kenny...g-progress.jpg