The good news is that your car wouldn't run at 21 : 1 so you definitely have a WB issue.
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The good news is that your car wouldn't run at 21 : 1 so you definitely have a WB issue.
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The base for your lc1 with how you have it programmed is V/0.332+7.35. To correct for ground offset, you add or subtract the differance in offset from 7.35.
So, when lc1 is programmed for 2.500 and you use V/1+0 and it shows 2.300, you would change your +0 to +0.2 to make it read 2.500
That transfers over to your V/0.332+7.35. You add the same 0.2 to 7.35 to make it 7.55.
The numbers will never be perfect, but you get as close as you can. Numbers used as example cause its what you currently have. If your happy with your current set up carry on.
To be honest I guess I didn't know whether I should be using fuel trims or wideband to try to tune ve...
You will get a lot of varied opinions on this. I like to tune idle and driveabiltiy area using fuel trims as much as possible. I have the histogram setup so anytime stoich is commanded it records fuel trims. The other histogram populates when anything richer then stoich is commanded using wideband error correction. Your wideband and your narrowband are never going to agree perfectly, and since you run off the narrow bands in closed loop I let them do the adjustments. It can be done either way based on preferance and there are exceptions to every rule!
I could only get 2 decimal places of accuracy in the table to correct the wb to 2.5 and it bounced quite a bit from 2.49 to 2.51
I called it good.
Also added fuel trims back to the table
Ok here is a log where I recorded fuel trims and AFR error.
Am I ready to paste the corrections into the VE table?
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Are you sure? Did you notice his fuel trims maxing out positive when he was logging them?Quote:
Originally Posted by fullthrottle
You should log both front 02's instead of both driver side 02's. The data from the fronts is more relevant. Add cylinder airmass back to your table too so your spark histo works. It would make it easier to dial in your VE if you turned off your LTFT's too. You could maybe write a histogram to add your trims together, but I choose to use STFT's alone and increase cell hits required as I go.
Get your idle fuel dialed in with the engine at full temp and don't touch that cell again regardless of what your trims tell you in that cell. You will hit that cell at other loads and it will change the fueling requirements for it. I like to satisfy idle and leave it alone.
I didn't realize i had b1 for both sensor - that was unintentional.
Added cylinder airmass to the table.
And none of the guides I have read anywhere mention 'how' to get idle fueling dialed in everything just says to go drive.
Do I just sit and idle then paste the trims from that?
How do I get more than just two cells since it reallly only sits at idle in two or maybe three cells once its up to temp.
This is why is was wondering if I have a false lean because of the 47 degrees overlap sending raw fuel out the exhaust.Quote:
Originally Posted by blownbluez06
Also wasn't sure if I could trust fuel trims at idle if I do have this issue.
Edit:
Now that I think about it though... I added some to the VE in the leaner areas and the AFR went to 18.x at idle.
No need to adjust more cells than you're idling in for idle. Just make sure you don't wipe them out when you are working the VE after driving because you WILL momentarily hit those cells under different conditions and it will reflect an adjustment needed. For cams like you're saying you have, raise your EOIT up in the warm cells. You don't want to raise them cold because shooting fuel on the back of the valve serves a purpose when the engine's cold. If you have the cam in your sig, I don't see 47 degrees overlap there. I see something closer to 0, calculating in my head. Without doing any calculation, I would start by raising the EOIT to somewhere around 6.5 if you have a cam with 47 overlap.
I will do that.
Can card says 48 degrees
Maybe I am looking at the wrong thing?
http://i1202.photobucket.com/albums/...577AE8A744.jpg
Yeah, 48 calculated at 0. The way I see it, overlap should be calculated @0 or .003". but I see people calculating @ .050" and followed suit.
Ok I have been logging fuel trims.
Adding them to the VE table, smoothing a bit.
Then driving some more
Seems like I am going back and forth with things.
When I add some then drive it some it tells me I need to take a bunch back out
Some cells show to add toward the beginnning of the log but toward the end it gets back towards zero
Also there are times when it seems like a dead spot in the pedal, if I back out of it some I feel more power.
I looked at the log and during the one time on this log (right at the end)
The spark advance is at 3 deg. until I let off some.
Have heard popping out the intake when this happens.
As soon as I back out of it advance goes up and I can feel the extra power.
Feels like I am just going in circles here.
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Why have you applied a maf enhanced custom o/s to the file I provided and then tried to tune the ve with it?
I didn't do any of the ve tuning with that.
Just applied it today to see what rtt looked like.
Only the last log was made with that tune.
Will it act differently or should I change back?
Attachment 45438Attachment 45439Well anyhow I have over a dozen logs trying to straighten out the ve up to 4k rpms and it seems to keep going back and forth.
Could my timing be an issue here?
Is you look at the attached log (same config as all the others) you can see where I get to about 25% on the tps and let off to 13%
The timing dipped to 10 deg at first and as soon as I let off it went up, then I could get into the throttle more.
Wouldn't this be affecting the fuel trims and thats why I am chasing my tail trying to nail down the ve?
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do some thing I have not seen talked about here. lean it out. I have several times had cars that were running so rich they pegged all the sensors lean. At this point it will not hurt any thing as long as you are watching and being care full. Lean it out by 10 then 20% and see what happens ;)
I am very new to tuning - and not to get off topic here, or challenge anyones knowledge, however a few times in this thread I heard it said that a car would not run at 21:1. I recently used my wideband (it's first use), to tune an older motorcycle carb. The guage read 21:1 at idle, as well as at many times throughout the powerband, excluding hard accelleration (which would run in the 17's). I looked into all sorts of reasons for this, and came down to the conclusion that it was in fact running that lean. It is now running at 11.5 at an idle and 14 going down the road, with 12's during hard accelleration and 16's on decel (by playing with jets and idle mixtures). It had run for years with the carbs set the way they were, however the plugs always "read" as being very lean. Either way, my 2 cents, they will run that lean, and I would trust the sensor.
However, just to throw it out there, an exhaust leak will make the sensor read very lean, despite still having "rich" smelling fuel.
Also large duration cams at low rpms can allow intake air to flow directly into the exhaust correct? resulting in the same scenario of a false lean reading on the sensors side.