a/f command problem

[Grip Ronin]

Originally Posted by steve99

Id give it a couple of days and at least a 100 miles or more driving before you get too excited it may be related to some weird fuel trim learning or something else that only shows up after a while.

this maybe why people dont see it they only log just after a flash possibly and not after a week or so.

yea it might be back idk. it seems good sometimes but it started doing it after the oft tablet cord got loose while driving and set of some cluster codes and puts it in limp mode. cleared them all and this issue happened again.. otherwise it has been having alot of writing problem to the ecu, keeps failing to write. maybe ecu or the oft is shot

[steve99]

Originally Posted by Grip Ronin

yea it might be back idk. it seems good sometimes but it started doing it after the oft tablet cord got loose while driving and set of some cluster codes and puts it in limp mode. cleared them all and this issue happened again.. otherwise it has been having alot of writing problem to the ecu, keeps failing to write. maybe ecu or the oft is shot

Write fails not good ,suspect its the obd socket in car worn or loose sockets. Try a short obd cable extender right angle one best as you car cable tie it in and it does not hang down. Then lug oft into other end that way your not further wearing the car socket, if it rearly bad you may need to refit a new obd socket in car.

[Grip Ronin]

Originally Posted by steve99

Write fails not good ,suspect its the obd socket in car worn or loose sockets. Try a short obd cable extender right angle one best as you car cable tie it in and it does not hang down. Then lug oft into other end that way your not further wearing the car socket, if it rearly bad you may need to refit a new obd socket in car.

luckily its only 5 wires if i need to repin it lol

[Mr_Eyo]

I've been getting the same weird logging issues too:. 15.05 commanded AFR, OL, light to medium throttle. Actual measured AFR looks fine, car runs great, no CELs, no write failures. The only change I made to fueling is I made the CL load comp tables have offsets that make it match the POL table. It generally runs richer than the OTS CL map.

[tomm.brz]

I followed 3 guys with OFT in the last year and all of them have that kind of offset in the logged command afr value

[steve99]

During closed loop the rear 02 sensor can influence the commanded afr value log AFCorrection #3



If af#3 corrections not disabled then you will see some offset in commanded afr by the rear 02 sensor.

[tomm.brz]

I see the offset also with rear O2 Disabled

[steve99]

Originally Posted by tomm.brz

I see the offset also with rear O2 Disabled

thats strange
did you disable (zero) both tables ?

[Mr_Eyo]

So I logged almost everything I could find in OFT related to O2 and AFR for this and it looks like commanded AFR going to 15.05 under throttle correlates to something called a/f sensor voltage going below ~2V. There is no scaling matching this in the OFT defs I have; OFT has a front O2 sensor scaling in current, not volts.

https://datazap.me/u/protoformx/log-....96&tmax=15.06

I'll do more correlation analysis on this log in Octave after dinner.

[Mr_Eyo]

Originally Posted by Mr_Eyo

So I logged almost everything I could find in OFT related to O2 and AFR for this and it looks like commanded AFR going to 15.05 under throttle correlates to something called a/f sensor voltage going below ~2V. There is no scaling matching this in the OFT defs I have; OFT has a front O2 sensor scaling in current, not volts.

https://datazap.me/u/protoformx/log-....96&tmax=15.06

I'll do more correlation analysis on this log in Octave after dinner.

OK, here are some plots for:
commanded AFR = 15.06
RPMs increasing
Fuel system = OL

https://imgur.com/a/Ym8HhIv
First pic has the x-axes all sync'd are time in seconds.

Second pic is just the bottom right 2 plots with the gaps taken out. X-axes are just samples, not time.

Is there a measured AFR limit of ~13.5 for CL?

[steve99]

Post the oft log to www.datazap.me will be esier to read

[Mr_Eyo]

Originally Posted by steve99

Post the oft log to www.datazap.me will be esier to read

If this is for me, I did in the post prior.

[steve99]

Originally Posted by Mr_Eyo

If this is for me, I did in the post prior.

you commanded AFR is not logging correctly what calid is your tune ? are you using OFT V4 tunes ?

commanded afr may be being offset by the rear 02 sensor readings can you log AF#3 ? or alternative disable rear 02 sensor corre ctions by zeroing the two AF#3 correction tables

the rest looks ok, but i think your problem is just logging is incorrect for your rom/tune

http://www.ft86club.com/forums/showthread.php?p=2909412

[Mr_Eyo]

Originally Posted by steve99

you commanded AFR is not logging correctly what calid is your tune ? are you using OFT V4 tunes ?

commanded afr may be being offset by the rear 02 sensor readings can you log AF#3 ? or alternative disable rear 02 sensor corre ctions by zeroing the two AF#3 correction tables

the rest looks ok, but i think your problem is just logging is incorrect for your rom/tune

http://www.ft86club.com/forums/showthread.php?p=2909412

Thanks for the comments. I Just checked my defs in RomRaider and found I had the wrong one at the top (ZA1JN10D, my car is ZA1JK00D and it was the next one down). I think these logging quirks started around the same time I downloaded that def. Could writing a tune with the following year's def cause this? AFAIK, the logger would be using the ZA1JK00D defs, right?

I'm not sure I'm understanding your linked forum post, so let me see if I have it right. If the correct cal ID doesn't fix this, you're saying I can set the limits for my AF #3 sensor to 0/0, even if my RomRaider def puts it in a different group ("ALPHA AF 3 (Rear O2 Sensor)", not "Fueling - AF Correction/Learning") from what was shown in your screen cap?