Help Needed AFR Sensor Bank 1 Lean spike under WOT

[shadow85]

Does anyone know why my car will briefly but quickly and suddenly go lean on Bank 1 AFR under WOT as shown in the graph below.

As you can see, only the AFR on Bank1 spikes lean but only momentarily then goes back to normal rich condition, and that only happens under WOT.

 

Anyone know why that could be happening? Thnx

 

Car is Nissan 370Z Twin Turbo

Edited August 17, 2018 by shadow85

[zoomzoom]

Could be a misfire under load.

[shadow85]

Thanks for the reply.

 

I don't know if it is a misfire, I do know that Ecutek will momentarily cut throttle on the Injector Bank 1 when this situation occurs.

[KiwiRS4T]

  On 17/08/2018 at 4:03 AM, shadow85 said:

Thanks for the reply.

 

I don't know if it is a misfire, I do know that Ecutek will momentarily cut throttle on the Injector Bank 1 when this situation occurs.

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I don't think ECUtek has the capability to "cut the throttle" ...it only reports what it sees.

[shadow85]

Yes Ecutek does have the ability to 'cut throttle' when it detects certain dangerous conditions.

 

My tuner has even told me has setup failsafe on my tune. I just don't know if that has actually occured in my situation above, or something else is going on.

[zoomzoom]

  On 17/08/2018 at 4:03 AM, shadow85 said:

Thanks for the reply.

 

I don't know if it is a misfire, I do know that Ecutek will momentarily cut throttle on the Injector Bank 1 when this situation occurs.

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In the case of a misfire, the ECU wouldn't necessarily have to do anything. The chemistry of the situation with oxygen in the exhaust will read as lean, whether or not unburnt fuel is present.

[shadow85]

Looking closer at my logs it seems injector duty bank 1 momentarily shuts off just before the AFR on bank 1 goes lean.

So I am guessing something is turning the injectory duty bank off or it is not working correctly when it reaches 43-48% duty cycle under load, but only for a split second before it starts working again.

Edited August 19, 2018 by shadow85

[shadow85]

Well it was definitly a Ecutek throttle cut feature. It happens because something has gone hairy with my rear wheel alignment. Both rears had something like -18° camber, so it didnt take much hard throttle to totally spin sideways and Ecutek was fully cutting throttle. With VDC off, the throttle cut does not occur but then the car would go mentally sideways.

 

The alignemnt is now fixed up properly by a proper high performance alignment centre.

 

Lesson learned, do not goto Pedder's suspension for a wheel alignment.

[KiwiRS4T]

  On 10/10/2018 at 1:05 AM, shadow85 said:

Lesson learned, do not goto Pedder's suspension for a wheel alignment.

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For anything by the sound of it. Glad you got it sorted!

[GTSBoy]

I refuse to use the word that starts with P, let alone take my car to them.  Made that decision some 30 years ago!

[niZmO_Man]

  On 10/10/2018 at 1:05 AM, shadow85 said:

Lesson learned, do not goto Pedder's suspension for a wheel alignment. 

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This applies to 90% of "workshops" out there.

[zoomzoom]

For the love of Dog, always check nuts and bolts that have been touched by any tyre or suspension shops. Bob Jane tmart left my camber bolt loose once.

[shadow85]

Ahh damm. Yeah.

 

Well, my Pilot Super sport tyres was also not liking the extra power with VDC OFF.

I kept going easily sideways when smashing the pedal. I changed upto Potenza RE71R and now I almost feel like I am on Rails!