Gas Pedal Delay

wstar

Yeah that's troubling. My car's NA, the breathing mods aren't ideal for very-low-end torque, and I'm on 11" wide rear rims (295 tires), and I can break the rear end loose in 1st every time if try, regardless of hot weather or runtime. I usually don't though, I like my tires to last a bit.

Edit: although I should add, it probably helps that I have a very stiff rear sway and some weight loss in the rear

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IcedZ

My Z was basically stock. After the car got hot, no way I could break out in any gear without revving to 4k RPM and dumping the clutch. And yes DIGI, rev matching was affected when I had my car.
Hopefully gonna test drive a BRZ this week =D I'm really missing a sports car (and will not buy another 370 until this issue is resolved). I really wanted to love that car.

kenny's 370z

so something is dumping too much heat in the im causing this bogging.i cant get on the car too long without stopping before i experience this bogging.there has to be one thing that is dumping too much heat into the im besides the obvious heat soak. pcv hoses are not helping for sure.i plan to remedy some of that heat with oil catch cans.i will be looking to see what else i can do to eliminate as much heat as possible.

has anyone done a egr delete or is it even possible on this engine ? that would eliminate more heat from going into the im.and does anyone have a link showing the schematics and what is what on this engine ? i would surely appreciate it !

on a side note,when i have had the bogging,i stopped,popped the hood, and immediately put my hands on the tb's and they were cool to the touch in 82 degree ambient temp.so i know the intake and tb's are not the blame.pcv hoses on the other hand were hot.what is that thing on the back of the engine towards the top that looks like a small motor ? that thing gets very hot.sorry for some of these questions.i have done alot of research on here already and these few things is all i need the answers too por favor.

edit;and my oil temps were 195-205

IcedZ

Is it possible that the PCV valves are getting stuck open when the engine gets hot? That will cause a leaning effect, probably more pronounced at low RPM's.

kenny's 370z

possible.i will be trouble shooting everything i can think of to resolve this issue.i will find the culprit eventually.

EDIT; come to think about it,those pcv hoses ARE dumping extra heat into the front two piston holes.i will do something about this, this weekend and see what my results are for that.

IcedZ

Are the PCVs active? Or are they a standard passive valve on this car?
(I sold my Z, so I don't really have a way to check anymore)

kenny's 370z

i will have a better understanding of them this weekend when the car is cold to investigate and work on.ive only had this car not quite 6 weeks yet.

wstar

What do you mean by active or passive? There are PCV check-valves screwed into both head covers, which connect to tubes that go straight to the intake manifold for vacuum sources.

Then there are unvalved lines going from elsewhere on the covers to the air intake tubes for crankcase fresh air supply, which have baffles (presumably to prevent catastrophic problems w/ intake backfires).

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kenny's 370z

I pinched a pcv line today on lunch and i didnt hear any click of the pcv valve like i would on other cars when the pcv valve is operating correctly.that tells me there is an abundance of heat being sucked into the im.i am pretty sure these pcv hoses are the culprit for my bogging or hesitation after a couple of spirited runs.add hot oil mist into the equation and there you have it.i'll find out soon enough after i put some cans on.this is my next mod for sure.anything to stop a direct heat path coming from my valve cover to the im.

wstar

Well, there is a proper PCV valve on those lines, assuming you're playing with the right ones (the ones that run to the pair of outlets on the front of the intake manifold). Maybe the valves have gone bad?

I do run an Al catch can way over in the battery compartment, but I wouldn't think the relatively small volume of hot PCV air would be a significant factor anyways. An actual failed PCV valve could cause all kinds of problems, though.

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IcedZ

Meaning is it a normal check-valve, or are they electronically controlled (sensor + actuator hooked into the car's computer).

kenny's 370z

yes ,the ones i checked are the ones going into the front of the manifold.im still a noob with this car so if i dont hear a click by pinching the pcv hose,how can i tell if the valves are bad ?

wstar

Good question, no idea . They're cheap, and I'm at 30K miles. I just put in an order for a pair of them from courtesyparts because, hey, why not.

Edit: parts list from the order (2x rubber O-rings, left/right PCV valves):

2 x [11812] RUBBER PCV,VALVE - 370Z (Z34) 2009+ (11812-Z34001) = $4.92
1 x [11810PA] VALVE ASSY-CONTROL - 370Z (Z34) 2009+ (11810-Z34004) = $14.57
1 x [11810P] PCV VALVE - 370Z (Z34) 2009+ (11810-Z34003) = $14.57

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robones

Well its really hard to judge why the lack of response if you start messing with the car's internals. My engine is completely stock and if I keep my revs at 3 k and slam on the accelerator, my wheels spin and i am pushed to the back of my seat. Its such an amazing feeling.. I can't and will not touch the engine because I have it warrantied up to 100 k miles 7 years.

kenny's 370z

i had the bogging issue after spirited runs around curves and such while i was stock.i have eliminated alot of whatever this issue is and when im done,i wont have this problem anymore.if i drive the car normal,i dont have a problem.but i didnt buy this car to putt around curves and keep revs under 5k