Car will not follow commanded AFR

Discussion of tuning specific to MAZDASPEED6/MAZDASPEED Atenza/Mazda 6 MPS vehicles
mituc
VersaTuner guru
Posts: 910
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: Car will not follow commanded AFR

Post by mituc »

ShakesReaper wrote:This happens all the time as far as I know.

My drive home is about 30min, of witch 15min is city driving and 15min on the highway. I can post a log of the entire trip if you like. from cold start till I switch off at home.
Just export your log into CSV, zip it and post it somewhere here. It may be useful to look at the whole thing.

ShakesReaper wrote: The logs I attached were not after a detonation event, but if that is the case, how long will the ecu remain in the KR Present AFR tables before reverting back to the normal AFR tables?
A few hundreds maybe tens of a second, there's a setting for that in the tune which is given in CPU ticks but to be honest I don't know what's the CPU frequency of our ECU.
2008 Cosmic Blue Mazda 3MPS
Build engine + WMI + GTX3071, ~476WHP @31-32PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 320-ish BHP

ShakesReaper
Posts: 25
Joined: August 27th, 2012, 1:02 am

Re: Car will not follow commanded AFR

Post by ShakesReaper »

Hi

I am not sure what you will see with the whole thing, but I have attached my entire commute in one log.
Attachments
Data log - 2016-08-30 06.44.30.csv
(714.33 KiB) Downloaded 220 times

mituc
VersaTuner guru
Posts: 910
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: Car will not follow commanded AFR

Post by mituc »

Ok, Try changing the target AFRs back to stock on the 500rpm column and on the 0.125 load line. Then for the next column (1000rpm) do a linear interpolation between the 500rpm line and the 1500rpm line.
Same for the 0.1875load line, do a vertical interpolation between the 0.125 and 0.25 load lines. The idea is to smooth that out AND to leave to stock the load/rpm lines where the secondary O2 sensor will have a word to say about the commanded AFRs.

...And to answer your questions, there were a few cells where the commanded AFR was above 1, even 1.021. But in the whole log I don't think there were more than 20.
2008 Cosmic Blue Mazda 3MPS
Build engine + WMI + GTX3071, ~476WHP @31-32PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 320-ish BHP

ShakesReaper
Posts: 25
Joined: August 27th, 2012, 1:02 am

Re: Car will not follow commanded AFR

Post by ShakesReaper »

Thanx.

Will try that and give some feedback.

My question though, why do you need to change the lower values to stock? I thought that the ecu will try and reach whatever you put in the tables?

ShakesReaper
Posts: 25
Joined: August 27th, 2012, 1:02 am

Re: Car will not follow commanded AFR

Post by ShakesReaper »

good news.

Did the 'fix' and went to town quickly. commanding 1.020. map still has to settle and will be doing a highway log again on my way home.

Any body here running leaner than 1.020?

mituc
VersaTuner guru
Posts: 910
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: Car will not follow commanded AFR

Post by mituc »

This is what I was running but I went back to stoich 250kms later because I didn't like how the car was feeling when I was accelerating slowly and the load/RPM was in that area with lean commanded AFRs.

I never tried to go from 1.037 back to like 1.02 or something because I didn't see the point. Also, after 250kms the fuel economy figures where about the same as before on the same segment of road. But that's also part of the fact because here in Romania we have mostly roads where we need to do a lot of overtaking, slowing down + accelerating, and things like that, so not too much highway or express roads. Maybe in highway cruising mode you can pull some better MPG figures if you can keep the RPM and load within those intervals.

ImageImage
2008 Cosmic Blue Mazda 3MPS
Build engine + WMI + GTX3071, ~476WHP @31-32PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 320-ish BHP

ShakesReaper
Posts: 25
Joined: August 27th, 2012, 1:02 am

Re: Car will not follow commanded AFR

Post by ShakesReaper »

Update on the tune.

When the tune was still fresh, the car was commanding 1.021, but as soon as everything settled, commanded AFR went back to 1

mituc
VersaTuner guru
Posts: 910
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: Car will not follow commanded AFR

Post by mituc »

The tune options has the secondary O2 disabled?
2008 Cosmic Blue Mazda 3MPS
Build engine + WMI + GTX3071, ~476WHP @31-32PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 320-ish BHP

ShakesReaper
Posts: 25
Joined: August 27th, 2012, 1:02 am

Re: Car will not follow commanded AFR

Post by ShakesReaper »

No I do not have the sensor disabled

ShakesReaper
Posts: 25
Joined: August 27th, 2012, 1:02 am

Re: Car will not follow commanded AFR

Post by ShakesReaper »

Should it be?

Post Reply