AFR questions, logging with SSFTC

[f1yen]

Hey guys,
After recieving the FTC, I am logging and changing my settings slowly, I am very confused as to how my AFR in open loop is so jumpy???
I realize it will fluctuate whenever it is in closed loop..... but It is jumping around a whole lot...the largest jump in this graph is from 12.25 to 10.71

<a href="http://s1337.photobucket.com/user/f1yen/media/jumpy_afr_zpse7ee5582.jpg.html" target="_blank"><img src="http://i1337.photobucket.com/albums/o662/f1yen/jumpy_afr_zpse7ee5582.jpg" border="0" alt="JumpyWOT_AFR photo jumpy_afr_zpse7ee5582.jpg"/></a>


I also before commented about my AFR seeming to swing alot more than I seemed to remember... logging freeway speed, I logged the swinging of 15.6 to 13.3....This being the largest swinging I have seen. a video of freeway: http://www.youtube.com/watch?v=YFCvi5RgMPo


I feel like the graph should be less choppy...... I definitely dont want to tune around a problem..... Does anyone else have logs that they can post?

In open loop, the problem could be fuel related (faulty/slow injector? or fuel pump? of which I do not know how to test those )
Boost leak done yesterday, and absolutely no leaks except for some leaking into the cylinders (open valve?)

Right now I am not using the SSFTC overboost function, because When I use it, my STFT's increase to +25 in about 3 seconds, and I am not a fan of chasing my tail after trims. I have also replaced my MAF within the last 3 months, and a new front denso o2 sensor within this last month. No audible/visible exhaust leaks, I am heistant to seafoam the engine (for exhaust leak), because I heard they break o2 sensors, and I don't recall how expensive the MTX-l wideband one is....

Hopefully one of you can either share with me/post on here logs or screenshots of logs?
Any help would be appreciated

 

[tweety2300]

Sub

 

[J_Naoto]

here's a log of mine from last year. it's better now after retuning a few times and i've fixed the rich spike, but still not completely smooth.

 

[f1yen]

Thanks J_naoto, do you have numbers for what the jumps in your data look like... I am getting jumps in the order of 1.5 points of AFR... how the hell am I supposed to get towards a power friendly AFR if I need to stay at (12.1 - 1.5 =) 10.6 AFR....

On a side note, I swapped injectors to see if one was possibly bad, looks like no change, I pulled a 1 - 1.4 degrees of timing, and will report back tonight.

 

[J_Naoto]

i'll have to check. looking at my wideband, it's a pretty much between 11.9 and 12.5 though

 

[f1yen]

sorry to bring this up again, Can anyone else send me /post their logs....

I am aware of noise that may happen in an electrical system.... but this is noticable on the WB gauge and in the loggs... unlike pomidor's post in the AFC-SS thread http://www.mazdas247.com/forum/attachment.php?attachmentid=199173&d=1352043038
those look like interference/noise to me.

For instance, on some of my logs, zoomed all the way in shows about 7 data points on the upside of the "spike"...

Pulling timing did nothing, I thought maybe i could have had flamefront problems? guess not

back to basics; air, fuel, spark :
After doing a leak test... I saw/heard almost zero leaking... except a small ammount past a valve/cylinder..(audible still) So i am assuming that I have air
Spark is there, and if I had a misfire, I should notice the WB peg lean when the puf of oxygen goes downstream but I dont see that
And this leads me to fuel... for me, I have little tools to be able to diagnose this... suggestions are welcome.

edit:: I may pull off the EGR wires to see if maybe that helps, but if it were egr related, wouldn't I have poor idle problems?

I still have a spare fuel pulsation dampner and spare fuel press regulator.... the current one seems to work fine, no fuel in vac line etc.
....any help appreciated :/

 

[jdwk]

J_Naoto's log shows the closed->open transition very well. You can add as much fuel as you want before and pull as much as you want after but unless you can force open loop earlier, there is no way to consistently get rid of that transition.

Here is a collection of some of my more interesting screenshots, although the explanations behind them are kind of scattered around on this site. Mostly in the FIC thread.

http://imgur.com/a/9kIRO#0

Your video is perfectly normal, perhaps slightly rich. You should be in closed loop in this scenario and the AFR will oscillate back and forth across 14.7 AFR (.5V from the primary narrowband O2). The cycle is exactly one second long from peak to peak. Now if you are doing any O2 manipulation with the SSAFC then all bets are off. In theory, the SSAFC will oscillate the O2 override in sync with the PCM keeping the STFT's at a minimum while being able to trick the PCM into adding fuel with the MAF. However, it should only do this once past the specified boost limit.

The FIC was much better for debugging since I could log the injector duty cycle, and see what the car was trying to accomplish. Misfires tend to throw AFR's off the chart lean, and you'd feel them, so I doubt that is the issue. I am not even really sure there is an issue. J_Naoto shows some pretty significant variation even after entering open loop as well.

I am not sure I totally trust this software and the SSAFC. What wideband are you using, does it have it's own PC connection and software? Most do. Try that and see if you see the same thing. Do long runs in 5th gear at WOT to ensure open loop.