O2s flatlining-railing, I just cannot figure this out
O2s flatlining-railing, I just cannot figure this out So Ive spent over 3months with countless number of adjustments on the tunes to figure out wtf is causing this problem. Attached is a shot of my chart. You can see when the o2 rails the STFT just goes south because it thinks its running rich. Then you got times where the o2 flatlines and then the STFT goes positive because it thinks its running lean.
You can then see in the 2nd attachment of where the histogram shows that its lean on the low map areas on the decels. I exported the histogram and looked at it in excel after sorting the data and noticed that the 2950-3050hz range has LTFT values of +8 alot. But then at the same time the same range also shows alot of -8 values. So its like if I bump up the calibration for that Hz value on the MAF calibration table, then I will just make it really rich for the areas that its already showing -8.
I have SVO30 injectors in there and my calibration is definetely correct. I used to have the 60lb mototrons in there and was seeing similar problems but at a much larger scale where the O2 would flatline or rail for alot longer period and would get -30 LTFTs.
I just cannot seem to figure this out. What am I doing wrong?
Here is the scan file and HPT tune to look at.
http://www.turbofedmax.com/Z06vette/...HPTandScan.zip
Ive also noticed that in SD mode it doesnt do this where I see Lean LTFTs in the low MAP areas and Rich in everything else.
Dixit
You can then see in the 2nd attachment of where the histogram shows that its lean on the low map areas on the decels. I exported the histogram and looked at it in excel after sorting the data and noticed that the 2950-3050hz range has LTFT values of +8 alot. But then at the same time the same range also shows alot of -8 values. So its like if I bump up the calibration for that Hz value on the MAF calibration table, then I will just make it really rich for the areas that its already showing -8.
I have SVO30 injectors in there and my calibration is definetely correct. I used to have the 60lb mototrons in there and was seeing similar problems but at a much larger scale where the O2 would flatline or rail for alot longer period and would get -30 LTFTs.
I just cannot seem to figure this out. What am I doing wrong?
Here is the scan file and HPT tune to look at.
http://www.turbofedmax.com/Z06vette/...HPTandScan.zip
Ive also noticed that in SD mode it doesnt do this where I see Lean LTFTs in the low MAP areas and Rich in everything else.
Dixit
Some say the issue is the O2 switching, I cannot seem to get a clear definition on what to change and how much to play with the O2 switching voltages. Ive seen the EFILive document but not 100% sure how that applies to HPTuners or how to make the changes. Their document seems to talk more about how the oscillation wave looks and how high and how wide it should be and what it means.
Dixit
Dixit
My minimum pulse width is set to 1.0 across the board. So that was lowered. The closed loop proportional base vs airflow mode, I have no clue about that or what it does. But I think I modified it at one point after reading a few things and the help. Heres what that table is now
Heres it stock
So I really only modified the first three. BTW, my tune is on that link if you wanted to snoop around.
Dixit
Code:
13.00000 16.00000 25.00000 50.00000 50.00000 50.00000 50.00000 50.00000 16.00000
Code:
26.00000 33.00000 50.00000 50.00000 50.00000 50.00000 50.00000 50.00000 16.00000
Dixit
On The Tree
Joined: Dec 2004
Posts: 100
Likes: 0
From: Satellite Beach, fl
Originally Posted by Dixit
You can then see in the 2nd attachment of where the histogram shows that its lean on the low map areas on the decels. Dixit
Right but if you look at the scan its not going into DFCO. When it does the fuel is off and you will see spark and LTFT and STFT at 0. So if anything I would be seeing zero but most of this is with it not even entering DFCO.
I seem to notice that in SD that it runs fine, dont get these lean cells, its perfect in SD where I got everything between 0 and -4. I just dont understand why the MAF wont get to that. Ive noticed the 3000hz is the ones that is causing this, but when I raise the calibration for that I fix the low MAP areas but then my idle (which also floats at 3000hz) ends up being -10 LTFT.
Dixit
I seem to notice that in SD that it runs fine, dont get these lean cells, its perfect in SD where I got everything between 0 and -4. I just dont understand why the MAF wont get to that. Ive noticed the 3000hz is the ones that is causing this, but when I raise the calibration for that I fix the low MAP areas but then my idle (which also floats at 3000hz) ends up being -10 LTFT.
Dixit
On The Tree
Joined: Dec 2004
Posts: 100
Likes: 0
From: Satellite Beach, fl
Originally Posted by Dixit
I seem to notice that in SD that it runs fine, dont get these lean cells, its perfect in SD where I got everything between 0 and -4. I just dont understand why the MAF wont get to that. Ive noticed the 3000hz is the ones that is causing this, but when I raise the calibration for that I fix the low MAP areas but then my idle (which also floats at 3000hz) ends up being -10 LTFT. Dixit
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I'm not that familiar with the SVO flow ratings. Are the injectors you're running rated at 30lbs/h @58PSI or @ 43.5 (3 bar)?
Using the injector flow calculator if your injectors are rated at 30#s @ 43.5 (3 bar) then your IFR table should go from ~34-37.
Using the injector flow calculator if your injectors are rated at 30#s @ 43.5 (3 bar) then your IFR table should go from ~34-37.
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Verdad Gallardo Purrvert, I dont think it would be an injector seal since I would see the same problem in SD mode. I dont think it can be the FAST intake seal either cause should see the same problem in SD mode as well. Only thing I can see is the After the MAF the seal.
Dixit
Dixit
Originally Posted by muncie21
I'm not that familiar with the SVO flow ratings. Are the injectors you're running rated at 30lbs/h @58PSI or @ 43.5 (3 bar)?
Using the injector flow calculator if your injectors are rated at 30#s @ 43.5 (3 bar) then your IFR table should go from ~34-37.
Using the injector flow calculator if your injectors are rated at 30#s @ 43.5 (3 bar) then your IFR table should go from ~34-37.
Code:
36.14916 36.33518 36.58320 36.76922 37.01724 37.26526 37.45128 37.69930 37.88532 38.07133 38.31935 38.50537 38.75339 38.93941 39.18743 39.37345 39.55946
Here's a couple of ideas. Don't know if they are good ideas, just ideas 
Check the rating for the injectors. Some injectors are flow rated at 3 bar, or 43.5 lbs. Not sure how much difference this will make, but if the injectors are rated at 43.5, then your current numbers will cause you to run a bit leaner.
I've found the offset/volts/kpa table to have the biggest affect on fueling, after the IFR table. It looks like these values are dependent upon the type of injector, rather than the flow. For example, my 42 SVOs liked one setting where my 42# Delphi's wouldn't run well with the same setting. If you PM me your email I'll send you the tune that worked well for my SVOs. You can copy the offset/volt/kpa table from there.
Check the rating for the injectors. Some injectors are flow rated at 3 bar, or 43.5 lbs. Not sure how much difference this will make, but if the injectors are rated at 43.5, then your current numbers will cause you to run a bit leaner.
I've found the offset/volts/kpa table to have the biggest affect on fueling, after the IFR table. It looks like these values are dependent upon the type of injector, rather than the flow. For example, my 42 SVOs liked one setting where my 42# Delphi's wouldn't run well with the same setting. If you PM me your email I'll send you the tune that worked well for my SVOs. You can copy the offset/volt/kpa table from there.
These are Ford SVO 30s. There was a huge debate on whether they were are rated at 40psi or 43.5. But I took th 40psi and seemed to be okay. Above was my IFR table that most seem to use for the 30 SVOs. Ive tried to pay with the offset table and never could get a good idea on how to do it. I tried the method of creating a custom map against LTFT and adjusting it that way and still no go.
I then tried values of the SVO30s from say a Ford ECU where someone converted the values and used that map, and saw my LTFTs go from almost being spot on to about -30. So I knew that didnt work. I attached the spreadsheet some guy made, that I used for the SVO, never worked.
Dixit
I then tried values of the SVO30s from say a Ford ECU where someone converted the values and used that map, and saw my LTFTs go from almost being spot on to about -30. So I knew that didnt work. I attached the spreadsheet some guy made, that I used for the SVO, never worked.
Dixit
Last edited by Dixit; Mar 27, 2012 at 11:22 PM. Reason: removed email
