Sudden lean running *with logs*

Discussion of tuning specific to MAZDASPEED3/MAZDASPEED Axela/Mazda 3 MPS vehicles
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tim.c4
Posts: 2
Joined: April 8th, 2012, 1:48 pm

Sudden lean running *with logs*

Post by tim.c4 »

Have a 2007 3 MPS, Been tuning it with versatuner, its got a corksport intake, autotech hpfp, forge bpv and a test pipe.
Did logs yesterday and AFR Actual was pretty much spot on Commanded.

Today flashed a new map, with no change to afr or maf cal.

And my afr is lean. for the whole WOT run the actual afr was 0.5 -0.6 leaner than commanded afr.

Been using this maf cal for months, the car had done 100 + miles on the map before the logs were taken.

LTFT at idle is < 2
Stft at idle is < 5

Logs attached, any help appreciated
Attachments
v.1.03 LEAN logs.zip
Running lean
(12.06 KiB) Downloaded 598 times
hpfp v.1.02.zip
Running normal
(19 KiB) Downloaded 605 times
mituc
VersaTuner guru
Posts: 1324
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: Sudden lean running *with logs*

Post by mituc »

You're knocking quite a bit at WOT, close or above the danger threshold. For some reason the knock AFR tables are leaner for our cars than the normal AFR tables. Maybe the culprit is there.
Other than that there may be a post-MAF leak, some gas very rich in oxygen (too much ethanol, too many additives containing other stuff rich in oxygen, and so on).

So go back to the advance timing tables you've had with the last tune and watch for knock after you reflash.
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
tim.c4
Posts: 2
Joined: April 8th, 2012, 1:48 pm

Re: Sudden lean running *with logs*

Post by tim.c4 »

The only difference between the maps is the BCDS table was slightly tweaked. It was running different fuel, the second log would of been on 97 Ron fuel as I couldn't get 99Ron, the first logs were 99Ron. Thats the only change between the logs.
Ltfts at idle are less than -2?
skiptownmcat
Posts: 383
Joined: August 3rd, 2011, 11:29 am

Re: Sudden lean running *with logs*

Post by skiptownmcat »

It's only knocking due to it running lean, Tim had a solid tune dialled in and was seeing no more than .35 and most of the time zero kr. I'm thinking a leak at the turbo inlet.
Tuned with Image by Image

Su tmic/corksport intake/kmd internals/grimmspeed ebcs/jbr ssp/forge bpv/3" custom tbe
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