Help me diagnose this problem: I can't rev past 3500 RPM intermittently (AK370Z)

DIGItonium

I'm pretty ignorant about sensor locations, but there was discussion about making a small heat shield. Think it's possible to silver or gold wrap the sensor body?

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shadoquad

lol it's nature's way of telling you to buy a vette

*Ducks flying objects*

Zenmaster

You could be misfiring and the Z is in failsafe.
Happened to me

dima370z

the have the same problem occur after i washed my car. the rpms woudlnt go past 3500 it shuts it down .. what can be the problem?

dima370z

i have the same problem^^how do i fix it?

arch

Check post #25
Help me diagnose this problem: I can't rev past 3500 RPM intermittently (AK370Z)

elia_ebyss

I have the same problem after uprev tune

The problem was repeated more than once, and if it became a problem i switch the car off and changed the map and turn on the car and the problem will end.



Is it possible to be the cause of the problem within the image ??

juld0zer

hmmmm crank and cam angle sensors eh?

i've taken all 3 out and cleaned them before - but this was a while before i was having this 3500rpm ceiling issue. I took out the crank sensor as i was having issues with my syncrorev-match being a bit sloppy (felt like i could rev match better). At the time, I cleaned off some black particles on the sensor tip which i believe is clutch dust. SRM definitely became more accurate after that, but i have to emphasise that it wasn't a huge caked on amount of dust but more like a few splatters.

Both cam sensors appeared visually fine. Wiped down with a rag and refitted.

Wiring loom for crank sensor appeared fine without any excessive strain or tension on the cables. My only concern noted was proximity to the RHS cat and the heat affecting the wiring and sensor. At the time, i wrapped the wiring with exhaust wrap and a bit around the sensor also

Wiring going to both my cam angle sensors appears to be under quite a bit of stress. No idea why Nissan made the looms so short. A few other sensors' looms are stretched on my engine too (one MAF and the left side throttle body loom. Both of which i relieved by unclipping them from the nearby component).

elia_ebyss - get that joiner replaced ASAP. That's a lot of unfiltered air entering your engine. I bet you would have idling instability because of that leak. It would most definitely throw off your tune and afr. quick fix is a long suitable hose connecting the rocker cover to the intake pipe.

juld0zer

i have pretty much the same problem, except i dont experience a hard fuel cut. I just get an extremely sloooowwwww ramp up. It will redline but i'm more likely to run out of road before i reach 7500rpm. But it does feel dead around 3500rpm so getting it beyond that takes effort. This is with my foot to the floor. It's like having a fat passenger in summer with the a/c blazing, heatsoaked engine and trying to take off quickly.

I do have datalogs during my most recent experience of the issue - it's in my own post. Something stood out to me today - intake valve timing solenoid duty is normal vs a log when the engine was normal, but cam angle in relation to crank angle was very different. Still no code was thrown. I thought the ecu had the ability to detect incorrect cam angle vs expected angle?

Could it be my intake valve timing solenoids? Since the duty requested was fine but the cam angle shift was not.....

SerialCoderer

So I finally took my car back after 1000k miles of driving. The prognosis is I need an engine.


Luckily this is covered under warranty. Phew!

juld0zer

what were your symptoms?

SerialCoderer

My symptoms were not being able to rev pass 3500rpm on a cold start. Once the car was warmed up it ran fine 90% of the time.

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SerialCoderer

I finally got my car back the engine was replaced. The short block was replaced to be precise. The service tech told me that the problem I had was common with G37's this was the first he had seen it with a 370.

Now I have to drive another 1k miles to break it in.

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shirokenkami

Holy thread resurrection Batman!!!

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“The only thing necessary for the triumph of evil is for good men to do nothing.”- Edmund Burke

Knockoutpie

Looks like limp mode. Mine was a dirty MAF sensor. Dealer wanted $100 to replace but I just bought MAF cleaner for $3 and used a can. Good as new.