Should I be worried for these lean conditions

[Volcom86]

Hi all,

I have noticed these leans spots after I had my car tuned by a local tuner shop.

As soon as I go increase % on the throttle the AFR's will go into a lean spot for 200ms or so

 

 

https://www.dropbox.com/s/9dpqh3fwetd9y7f/cruise.llg?dl=0 (Log File) 

What is coursing these conditions - Is it the tip in enrichment?

Is it something I should be concerned about ?

 

Thank you in advance for your help 

 

[Adamw]

In general I think it probably wants a bit more accel enrichment all over but if if drives ok without any flatspots or hesitation then i wouldnt worry about the general low load cruising stuff that your first pic shows..

The lean spike in your second pic at the 9:23 mark I would be more concerned about since it is at WOT and peak torque RPM so it is going to be pretty prone to knock around that area.  Its hard to tell if it really is lean there or if it is something like a misfire that makes the probe read lean?

On the short burst you gave it just prior to this one (~9:21) it didnt go anywhere near as lean.  The main difference I can see from a fueling perspective was due to it being from lower RPM so got more accel enrichment.  So you could try adding a bit more accel enrichment above 4000 to see if it has any influence. Generally you dont need much above 4000, but it depends on injectors etc.

 

[Volcom86]

22 minutes ago, Adamw said:

In general I think it probably wants a bit more accel enrichment all over but if if drives ok without any flatspots or hesitation then i wouldnt worry about the general low load cruising stuff that your first pic shows..

The lean spike in your second pic at the 9:23 mark I would be more concerned about since it is at WOT and peak torque RPM so it is going to be pretty prone to knock around that area.  Its hard to tell if it really is lean there or if it is something like a misfire that makes the probe read lean?

On the short burst you gave it just prior to this one (~9:21) it didnt go anywhere near as lean.  The main difference I can see from a fueling perspective was due to it being from lower RPM so got more accel enrichment.  So you could try adding a bit more accel enrichment above 4000 to see if it has any influence. Generally you dont need much above 4000, but it depends on injectors etc.

 

Thanks for the Input again Adamw...

 

I forgot to ask if the lean spike in the log could possibly be coursed by CLL rate down settings impacting this? 

 

Thanks again for your feedback I really appreciate it.

 

Cheers, 

[Adamw]

No it doesnt appear to be CLL related.

[Volcom86]

Hey Adam,

 

Hope all is well.

 

I finally got to go do some testing.

 

I changed added some Accel Enrichment above 4,000RPM am I perhaps not giving it enough?

Attached log file.

https://www.dropbox.com/s/s8x6r4v3upesly2/test 7.6.2020.llg?dl=0

Injectors are 1,700 ID's  

04 MY05 STi with standard drive by cable throttle body 

 

I should also mention that my AFR sensor is in the middle part of the exhaust past the dumpipe section where it meets the middle section 

 

Thank you for any feedback 

[remski2]

Hi.

Your Right AVCS seems to be off target by quite a bit.

Could that be causing the AFR discrepancy ?

 

[Volcom86]

Yes, indeed thank you pointing that out it looks like the solenoid is lazy. I will swap them around and see if bank 2 will repeat the problem

 

Thanks, 

[Volcom86]

I have taken the solenoids out gave them a good clean ans swapped them around and success. Back where they are in sync. Thanks for pointing that out remski2

Still seeing the random lean spike. I don't understand it 

 

[remski2]

    Exhaust / wideband leak ?

[Volcom86]

11 hours ago, remski2 said:

    Exhaust / wideband leak ?

Could it be because the AFR sensor is so far away in the mid section of the exhaust? So it a delay factor and not a actual lean spike