AFR difference between the banks

bleunetizen · 03-26-2014, 11:16 AM

I find my AFR is always 0.5 richer on bank1, is this common?

this happens in open loop only, they are pretty close to each other in closed loop.

also found that MAF reading is slightly higher on bank 1 than bank 2 under open loop.

anyone with some ideas?

Chuck33079 · 03-26-2014, 11:17 AM

My tuner found a discrepancy as well. Apparently Uprev can only adjust fuel globally, so bank-to-bank variation means you have to une to the leanest bank. I'd assume there's a certain amount of variance that can't be avoided.

bleunetizen · 03-26-2014, 11:22 AM

thanks for the info

Chuck33079 · 03-26-2014, 11:25 AM

Ecutek apparently can adjust fueling by bank. Mine wasn't a half point off, so it didn't make a huge difference in my tune. A half point is a pretty big difference.

Megan370z · 03-26-2014, 05:05 PM

Quote:

Originally Posted by Chuck33079

Ecutek apparently can adjust fueling by bank. Mine wasn't a half point off, so it didn't make a huge difference in my tune. A half point is a pretty big difference.

Uprev can adjust fueling on each individual cylinder... just saying

roplusbee · 03-26-2014, 05:10 PM

I really depends on how far the tuner is willing to go to adjust/set your AFR targets.

Mine is about .5 off toward bank 2. Bank one being the richer bank. Omar has been playing with my car for a bit since it has been at UPREV for the past few months. I will report in once I pick her up.

Sent from my SGH-T889 using Tapatalk

Chuck33079 · 03-26-2014, 05:14 PM

Quote:

Originally Posted by Megan370z

Uprev can adjust fueling on each individual cylinder... just saying

Interesting.

Megan370z · 03-26-2014, 05:25 PM

Quote:

Originally Posted by Chuck33079

Interesting.

top right

Mitco39 · 03-27-2014, 09:05 AM

Quote:

Originally Posted by Megan370z

top right

Shouldnt the engine have long and short term trims that should handle these inconsistencies?

Megan370z · 03-27-2014, 11:28 AM

Quote:

Originally Posted by Mitco39

Shouldnt the engine have long and short term trims that should handle these inconsistencies?

you mean he ECU....

short answer yes,
but not all sensors are the same. There is tolerance that are acceptable in everything, OEM included.

I had that type of variance .5 to 1.0afr when I did my custom CAI and I fixed it with tuning.

Mitco39 · 03-27-2014, 11:41 AM

Quote:

Originally Posted by Megan370z

you mean he ECU....

short answer yes,
but not all sensors are the same. There is tolerance that are acceptable in everything, OEM included.

I had that type of variance .5 to 1.0afr when I did my custom CAI and I fixed it with tuning.

yes I did mean ECU sorry. Right but my concern would be once you start manually messing with the duty cycle of each cylinder how do you know that say you arent running lean on 2 cylinders and rich on the other one? I mean I guess you dont really know with the trim either, but atleast it is not a static value that you input and the ECU runs with as I would imagine setting the trim manually would be.

I am fairly new to the uprev side of things but I have been tuning engines for 4+ years with EFI Live and that would be one of the concerns I would have with manually setting trim values.

I agree that there is tolerances, its why you will only get rich and lean codes after the engine has exhausted its available trim values, but to me this is exactly what the trims should be doing, making sure each bank is running as closely as possible to the target AFR (whatever it is you are calling for).

Just my thoughts...

Megan370z · 03-28-2014, 11:43 AM

Quote:

Originally Posted by Mitco39

yes I did mean ECU sorry. Right but my concern would be once you start manually messing with the duty cycle of each cylinder how do you know that say you arent running lean on 2 cylinders and rich on the other one? I mean I guess you dont really know with the trim either, but atleast it is not a static value that you input and the ECU runs with as I would imagine setting the trim manually would be.

Just my thoughts...

just to give a sample example on this issue with Bank 1 & 2 not being equal.

adjust the whole bank that is leaner to the other side.
on the table it would be like
1:100%
2:105%
3:100%
4:105%
5:100%
6:105%

as for tuning for each cylinder.
I cant help you on this. I have a theory but I wont go on that subject.

DOOMMONKEY777 · 04-23-2014, 06:38 PM

Just did this cylinder adjustment to 104.69, A/F ratio is exactly the same, before it was about .50 different, also i can hear the engine running more smooth rather than like a tractor.

Jordo! · 04-23-2014, 07:05 PM

Yep. There's always potential for some variance between the banks -- not sure if .5 would be considered unusually high deviance tho'.

Can you monitor fuel trims for each bank -- how close are they?

Also, one MAF sensor may need to be cleaned or you could have one extra dirty filter.

DOOMMONKEY777 · 04-23-2014, 07:23 PM

Yeah i thought it was the filters as well so i looked at them they looked barely dirty and i have found a few tree leaves, cleaning that barely did anything. There was notice, but u can still hear that something was off. The A/F logging showed it was off by~-/+.50 from other bank. Found this post and adjusted it, now its right on the money they r both the same ty very much, if it wasn't for this thread and ppl's shearing i don't know when i would have figure it out.

03-26-2014, 11:16 AM	#1 (permalink)
bleunetizen Base Member Join Date: Jan 2014 Location: NZ Posts: 138 Drives: BMW M6, 530i, 370z Rep Power: 12	AFR difference between the banks I find my AFR is always 0.5 richer on bank1, is this common? this happens in open loop only, they are pretty close to each other in closed loop. also found that MAF reading is slightly higher on bank 1 than bank 2 under open loop. anyone with some ideas?

03-26-2014, 11:17 AM	#2 (permalink)
Chuck33079 A True Z Fanatic Join Date: Nov 2011 Location: Houston Posts: 12,265 Drives: 2011 370ztt Rep Power: 29539	My tuner found a discrepancy as well. Apparently Uprev can only adjust fuel globally, so bank-to-bank variation means you have to une to the leanest bank. I'd assume there's a certain amount of variance that can't be avoided. __________________ 2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent

03-26-2014, 11:25 AM	#4 (permalink)
Chuck33079 A True Z Fanatic Join Date: Nov 2011 Location: Houston Posts: 12,265 Drives: 2011 370ztt Rep Power: 29539	Ecutek apparently can adjust fueling by bank. Mine wasn't a half point off, so it didn't make a huge difference in my tune. A half point is a pretty big difference. __________________ 2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent

03-26-2014, 05:10 PM	#6 (permalink)
roplusbee A True Z Fanatic Join Date: Dec 2009 Location: Killeen, TX Posts: 2,360 Drives: 2007 350Z NISMO Rep Power: 23	I really depends on how far the tuner is willing to go to adjust/set your AFR targets. Mine is about .5 off toward bank 2. Bank one being the richer bank. Omar has been playing with my car for a bit since it has been at UPREV for the past few months. I will report in once I pick her up. Sent from my SGH-T889 using Tapatalk __________________ 2007 350Z NISMO #0618: Zerolift \| UPREV \| F.I. \| Greddy \| Competition Clutch \| Injector Dynamics \| Aeromotive \| Pioneer \| JL

04-23-2014, 06:38 PM	#13 (permalink)
DOOMMONKEY777 A True Z Fanatic Join Date: Sep 2010 Location: Crooklyn Posts: 1,013 Drives: 370Z 6psd-sport-pkg Rep Power: 21	Just did this cylinder adjustment to 104.69, A/F ratio is exactly the same, before it was about .50 different, also i can hear the engine running more smooth rather than like a tractor. __________________ Kids don't do Drugs, Drugs are bad, so let the professional druggies do Drugs for you. 537whp/496lb/tq@8-9PSI 93 octane

03-26-2014, 11:22 AM	#3 (permalink)
bleunetizen Base Member Join Date: Jan 2014 Location: NZ Posts: 138 Drives: BMW M6, 530i, 370z Rep Power: 12	thanks for the info

04-23-2014, 07:05 PM	#14 (permalink)
Jordo! A True Z Fanatic Join Date: May 2010 Location: nirvana Posts: 6,394 Drives: 2023 NATM Rep Power: 419	Yep. There's always potential for some variance between the banks -- not sure if .5 would be considered unusually high deviance tho'. Can you monitor fuel trims for each bank -- how close are they? Also, one MAF sensor may need to be cleaned or you could have one extra dirty filter. __________________ Enjoy it. Destroy it.

04-23-2014, 07:23 PM	#15 (permalink)
DOOMMONKEY777 A True Z Fanatic Join Date: Sep 2010 Location: Crooklyn Posts: 1,013 Drives: 370Z 6psd-sport-pkg Rep Power: 21	Yeah i thought it was the filters as well so i looked at them they looked barely dirty and i have found a few tree leaves, cleaning that barely did anything. There was notice, but u can still hear that something was off. The A/F logging showed it was off by~-/+.50 from other bank. Found this post and adjusted it, now its right on the money they r both the same ty very much, if it wasn't for this thread and ppl's shearing i don't know when i would have figure it out. Valentino and Megan370z like this. __________________ Kids don't do Drugs, Drugs are bad, so let the professional druggies do Drugs for you. 537whp/496lb/tq@8-9PSI 93 octane

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