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Tuner
VE tuning not working
I just installed my wideband and have it logging in HP Tuners, but i cant seem to figure out why i have so much trouble trying to tune VE. I have LTFT off, PE off, DFCO off, OL STFT off, i think that is all. no MAF, so it fails on startup. I log AFR error and paste over to the RTT table, but it just keeps getting either further off, or it changes the next log i do. I thought VE tuning with a WB would be just copy and paste for the most part. i also have noticed that i am getting a strong misfire, fuel related, at low load. it did not do this before i started tuning. Can someone tell me what I am messing up?
It is almost undriveable now at cruise rpm. If i put a single number, like 90 or 85 in the VE table, it seems to run better. I have also noticed that the VE error percent and the STFTs are nowhere close when i drive it, turning fuel trims back on.
Crap VE.hpl
Setup 2.cfg
Caddie2.hpt
files attached!!!
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Tuner
You need to be in open loop when tuning with a wideband. You also need to set your open loop commanded fueling to 1.0 and don't log the MAF if you don't have one.
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Tuner
I was when trying to tune. I thought I stated that. Sorry. I use the vcm controls to force OL. I have been playing with the Injector timing tables tonight to try to figure out why in getting misfires at around 2000 rpm. Delaying the injector pulse has helped get rid of almost all the miss. I have now seen a trend in my o2 sensors that has me worried.
My WB is installed in B1 just behind the o2 sensor. It reads solid numbers, but I get weird dips in my o2 output at low rpm. I don't know if the miss is causing the o2 voltage drops, or my o2 sensors are causing the miss, or I have something wrong with my injectors.
Should my o2 sensors read a steady voltage at a steady rpm? My WB seems to read a more steady voltage than my o2.
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Tuner
The OL STFT is turned off, so I don't have to worry about the EQ ratio on it. It is at 1 though.
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Tuner
The open loop EQ ratio is not set at 1 on the tune you posted.
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Tuner
I am sorry. I must have not saved the tune after flashing. The OL fuel trims are turned off, so the values do not matter. I did a reflash last night and the values are at 1. My VE table is completely jacked up right now. I'm going to work on smoothing it out tonight as a new starting point. I have a couple of extra o2 sensors that I'm going to plug in to see if I get a difference in readings.
My belief is that I have either an injector issue at low rpm, like being clogged, or I have some o2 sensors that are just not heating up properly.
I will post up new info tonight. Correct tune and new log, after I reset the VE table.
How do I get the o2 to go OL at idle? I would like to run the motor a little lean at idle, but my o2s keep correcting AFR.
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Why do you have a 2 Bar OS, but have the tune set up for a 1 Bar Map sensor?
Russ Kemp
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Tuner
No supercharger currently, so I'm running 1 bar. I'm also running a 1 bar map sensor, so that table is correct.
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Tuner
So...when I got home, I plugged the laptop in and ran a few logs. I adjusted the injector timing and I think I've found somewhat of a sweet spot. 6.5 boundary and 6.75 normal and makeup. I'm running a 5.7l stock can motor with 1.6 rockers. I have noticed a crisper throttle response and I had to add a little to VE at idle to get my fuel back to normal. It was lean, which I was told is good. No fuel smell anymore.
I turned off fuel trims and ran a few trips up and down my road making some adjustments. VE is looking much better, but I haven't done any smoothing yet.
I still have a slight miss at 2k rpm with no load, but I think it might be a combination of timing advance and plugs gapped at .060. I pulled some timing in the upper cells, no load cells, and it does a lot better.
I can now roast the tires from a stop, which is pretty good on a 3 ton SUV with 3.73 gears.
Does anyone have any ideas on how smooth my VE table needs to be? What would be the max jump from one cell to another?
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Tuner
I did some more investigating on my vehicle today after work. What I found is intriguing. I am getting a difference in commanded AFR and actual AFR when in closed loop. It turns out that my o2 sensors are setup to think that lambda is 0.4 AFR below commanded. So...when I try to tune with my wideband, I constantly go the wrong way because if AFR was perfect, I'd still see a -5% error.
I am looking into why the o2 sensors are off by that amount, since I know and have verified that my wideband is correct. For now, I am getting by with adjusting till I get close, then using the "paste multiply half" option. After only a couple of short trips, I managed to get it pretty dam close. I'm also thinking about upping my stoich to 15 so it will actually correct to 14.68 instead of 14.2ish.
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go back to your original OS and upgrade to 1 bar. current its 2 bar. and your VE table is just #%*&(@^(
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Tuner
My VE table in the tune I posted was that way for a reason. I was trying to show where the AFR error was sending me when I was trying to tune. That was the whole point of the thread. It seems to me that the people who know more about tuning, and have been doing it for years, don't want to help others who are just learning.
Telling someone that a table looked like shite is not helpful and if that is all you have to say, then please keep those comments to yourself. I don't appreciate "tuners" talking to others in a derrogatory manner.
Going back to 1 bar would get me what? Can you elaborate on why going back to 1 bar would solve my VE tuning issues? I don't see any benefit, besides only having half of a VE table.
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The #s in your VE table are no where close to being reasonable. Going back to a 1 bar OS will give you twice the resolution in the VE table. There is no reason at all to run a 2 bar OS when the vehicle is not boosted.
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Tuner
Well....I went to another forum to get help. I managed to get someone to explain a couple of things to me, instead of bitching about me having a 2 bar os while my supercharger is off the vehicle. So....thanks for looking at my problem, even though no one offered any help.
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You were offered help. Your replies indicated you thought you knew more than those people offering help.
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Tuner
So...going back to a 1 bar os will solve my problems? Yeah, that's going to work! If it does help, for some reason that no one is willing to explain, then when I go back to 2 bar, I'll be having the same problems again. What good would that do? Why not just fix the dam problem in 2 bar in the first place? Seems like a more logical choice to me.
Come to find out...having a 2 bar os on a non boosted vehicle was NOT the problem. So, going to a 1 bar os would have done absolutely nothing.
I guess someone willing to help me WAS smarter than you, or just actually tried to figure out what was going on.
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