Is AFR Oscillating Normal? | AEM
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Wankel88
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Last seen: 2 months 2 weeks ago
Joined: 09/22/2016 - 22:45
Is AFR Oscillating Normal?

Current setup is a 93 rx7 single turbo. Ive been having issues in steady throttle areas like my cruise. My logs show an intense amount of fluctuations to my targets. This same fluctuation also happens in my manifold pressure as well. Ill be cruising shooting for a rough 14.0 and the afr will sudenly spike n jump all around like mid 13s to high 15's and i can feel it in the drivetrain. Engine is a fresh rebuild but this is previous problems pre rebuild at this point. I feel like it could be several things but i cant justify and need some guidence. I feel like my o2 might be faulty, maybe a vac leak, Maybe my fpr has something to do with it? im not sure at this point.

 Vehicle was tuned by a professional which didnt mention any issues after the tune. Attempted a cross country road trip for a move. Drove the car from GA to CO. By TX in the second day it began to act like this and would even have trouble in the idle areas leading to some stalling. 

 Can you show me what a typical log of the lambda o2 sensor looks like? I dont know how to upload pictures. 

AEM_PT
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Last seen: 3 months 1 week ago
Joined: 05/22/2014 - 08:13
Are you using the internal

Are you using the internal lambda controller or an external unit?
What is your MAP smoothing setting at?

Wankel88
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Last seen: 2 months 2 weeks ago
Joined: 09/22/2016 - 22:45
Map smoothing is currently at

Map smoothing is currently at 30%, I run your 3.5 bar sensor and its tapped direct into the manifold via a block off plate. The Wbo2 is wired direct to the infinty and i run a second sensor to my gauge as a reference. I replaced the sensor and reocated the bung further downstream as it was too close to the turbine. Also found loose maifold bolts due to a powdercoating deal where the fastners pancaked the finish resulting in nuts that i was able to get another half turn out of. The afr seem to be better but still Jumpy. I can try a short log and upload it. 

AEM_PT
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Last seen: 3 months 1 week ago
Joined: 05/22/2014 - 08:13
Change your MAP smoothing to

Change your MAP smoothing to 80% - this should fix the oscillation and hunting.

Wankel88
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Last seen: 2 months 2 weeks ago
Joined: 09/22/2016 - 22:45
This helped a lot. Then

This helped a lot. Then signal from the wb is now more consistant with flucuations of roughly .3 to .4 Is that normal or should it be smoother? The Map sensor data trace looks really good now. 

https://i296.photobucket.com/albums/mm173/wankel888/Screenshot%203_zpsvq...

 

Wankel88
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Last seen: 2 months 2 weeks ago
Joined: 09/22/2016 - 22:45
Still lots of peaks and

Still lots of peaks and mountains from the data traces. I currently have feedback turned off. Are the "PID" settings for enabled feedback? The smoothing fixed some areas. When it gets erratic the map sensor correlates to it but I'm not sure what is effecting what. The map is smaller jumps compared to the afr logs. Someone mentioned potential noise. The sensor is wired up as the infinty manual has it. Power is supplied from the efi relay and is grounded through the ecu. Ecu is grounded to the engine. There is no high tension leads it crosses a path with.