Still lean in stoich!

[BRANDON.RYAN]

I had a similar issue with my truck. I tuned mine to run at 14.1 afr due to ethanol fuel and at idle mine would always want to run rich. I mean real rich. if you would idle it over 2 minutes the afr would drop to 12 and it would stumble. I found that if I adjusted the mv on the o2 sensor the afr would change accordingly. higher voltage = richer afr. currently in closed loop I'm running 14.1 afr with the 02 rich lean mv set at 855 and its working like a charm for me. I'm fairly new to tuning but its what worked for me (senior tuners feel free to chime in and correct me if I'm wrong by doing this) but I am going to try the integrator adjustment this eavning. but open loop tuning I had the afr dialed in at 14.1 and when I renabled closed loop it leaned out to 15.3 no matter what changes I made to maf and ve tables.

[Speed Freek]

I had a similar issue with my truck. I tuned mine to run at 14.1 afr due to ethanol fuel and at idle mine would always want to run rich. I mean real rich. if you would idle it over 2 minutes the afr would drop to 12 and it would stumble. I found that if I adjusted the mv on the o2 sensor the afr would change accordingly. higher voltage = richer afr. currently in closed loop I'm running 14.1 afr with the 02 rich lean mv set at 855 and its working like a charm for me. I'm fairly new to tuning but its what worked for me (senior tuners feel free to chime in and correct me if I'm wrong by doing this) but I am going to try the integrator adjustment this eavning. but open loop tuning I had the afr dialed in at 14.1 and when I renabled closed loop it leaned out to 15.3 no matter what changes I made to maf and ve tables.

Are you talking about where you can adjust the individual banks vs airflow tables?
It has cells from 0-16 and voltage ranging from what I am assuming is .366 to .551 did you change them all?

Spent another couple hours trying some adjustments in other maps and cant get it to richen up without going into SD tuning mode.
Still chasing my tail, but Ill get it eventually. Stubborn bastard tune!

[BRANDON.RYAN]

Are you talking about where you can adjust the individual banks vs airflow tables?
It has cells from 0-16 and voltage ranging from what I am assuming is .366 to .551 did you change them all?

Spent another couple hours trying some adjustments in other maps and cant get it to richen up without going into SD tuning mode.
Still chasing my tail, but Ill get it eventually. Stubborn bastard tune!

YES it should be called 02 rich lean and show voltages in mv. mine where all at 451mv. If you look around on the closed loop tab there will also be a tabe titled air flow mode and that will help piece it together. the air flow zones are listed at what maf flow rate is considered in the zone. I started changing mv at idle and worked my way from there. so basically the first 0 and 2. since your running lean try adding 300mv and watch the response at idle, if it helps its worth tuning the rest of the mv readings in other air flow modes.

[GHuggins]

YES it should be called 02 rich lean and show voltages in mv. mine where all at 451mv. If you look around on the closed loop tab there will also be a tabe titled air flow mode and that will help piece it together. the air flow zones are listed at what maf flow rate is considered in the zone. I started changing mv at idle and worked my way from there. so basically the first 0 and 2. since your running lean try adding 300mv and watch the response at idle, if it helps its worth tuning the rest of the mv readings in other air flow modes.

[Speed Freek]

Awesome I'll try that to force it to change the switching table. I did see the Airflow mode and saw a 0-16 cell count but didnt know exactly what that correlated to so I kept my booger hooks off the keys..
Boy do I feel INADEQUATE!

Thanks for the feedback, and I swear Im not as stupid as I may seem, thats my story and Im sticking to it.

[BRANDON.RYAN]

Awesome I'll try that to force it to change the switching table. I did see the Airflow mode and saw a 0-16 cell count but didnt know exactly what that correlated to so I kept my booger hooks off the keys..
Boy do I feel INADEQUATE!

Thanks for the feedback, and I swear Im not as stupid as I may seem, thats my story and Im sticking to it.

Hey gotta learn somehow. We've all been there at one time. Hope it works for you.

[Speed Freek]

Thanks, I am going to try and play with the tune again today, been super slammed with work and my own projects this week, I just got finished building a new exhaust system thats a 3" dual piping that goes to a 2 into 1 GIANT truck muffler so it only has a single 3" tailpipe now.
So its super quiet (sleeper!), so that helps when I am tuning the truck in the driveway now, its not so damn loud so the neighbors will appreciate that!

Gonna change the o2 switching voltage today and hope that will lower the AFR enough so that I can start to put a good tune in it.
I have a race coming up pretty soon (I race Off Road motorcycles in Extreme Enduro and Desert endurance events) so I need the truck to run properly pulling my trailer for 3.5 hours into a place where I dont want any problems, since it is in the middle of nowhere (Spangler, Ca) its going to run way too hot the way it is since it seems to think stoich is between 16 and 17 AFR.
My truck not tuned properly has kept me from racing this year so its pretty important that I figure this out,

Thanks for the help guys I'll report back once I change the values and see what happens! When I tried to change the voltage before I only changed it in the higher cells and now that I understand the correlation I see what I did wrong, I should have changed the lower cells to see a change in idle, since that was what I was trying to richen up, no wonder it didnt change anything...plus I got a break from trying to tune it so Im no so frustrated after taking that little time off.

[Speed Freek]

OK some progress finally!
I changed all the Bank vs. Airflow numbers in all airflow tables to 900mv, ended up too rich at its desired stoich number (roughly 14.0) then I adjusted them to 850mv and its still a bit rich so I have to change this number to my desired set point which is 14.5 to slightly compensate for our +/-10% ethanol content.
I still have a slight variance between banks due to the 02 mounting locations being asymmetrical so I'll have to adjust them until I am reading the same voltages on the O2 sensors.

Thank you for all the help, I know problems like I was having could end up to be a mechanical problem as well as 20+ other variables so thanks for your continued help, I understand it takes a lot of patience to deal with odd issues.

However that brings me to the bottom line, I still think its odd that I had to make such a drastic change in voltage to compensate for what the ECU wanted to see as stoich.
Some would assume exhaust leak, however its sealed 100%, I use MLS headers gaskets with Permatex (The Right Stuff) sealant on both sides of gasket and its all high quality male/female type V-band connections after the headers, so its 100% sealed, I built everything myself so I know this for sure.

I will adjust everything once I set the base value for Stoich but still seems odd that I had to change the Bank voltage switching value by so much. went from a max (in the higher airflow tables) of .366mv to 850mv to get what I wanted, thats more than double!
I havent changed the wideband sensor yet to verify Im not chasing an uncalibrated number but I will do that in the next few days to verify that I am on the right track.
As we all know understand that we need to know that our WB readings are indeed what they say they are, otherwise everything I do is for nothing or a very expensive (time-wise) lesson in checking your basics... Even though I saw many other thing that lead me to believe that is wasn't a bad WB sensor.