Dixit

iTrader: (1)

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

Dixit

iTrader: (1)

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

SideStep

Hey Dixit...


A shot in the dark but have you adjusted your minimum injector pulse-width or your closed loop proportional base vs. airflow mode???

Dixit

iTrader: (1)

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

Purrvert

If I'm reading this correctly, your decels will be lean because fuel is cut off (DFCO). Tune in SD mode with DFCO turned off or eliminated in your charts, leave DFCO off when tuning Maf. The low MAP areas will only be hit in decel, you may be able to leave them stock or slightly smaller.

Dixit

iTrader: (1)

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

Purrvert

Check for intake leak after MAF. Could be Fast intake or possibly injector seal that only leaks when in low MAP areas.

muncie21

iTrader: (14)

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.

Dixit

iTrader: (1)

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

iTrader: (1)

Thats my IFR table now. Its rated at 30lbs at 40psi so it calculates to almost 39lbs at 58psi.

muncie21

iTrader: (14)

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.

Dixit

iTrader: (1)

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

muncie21

iTrader: (14)

Sent you and email Dixit