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Discussion Starter #1
I had my car tuned the other day and well long story. Another tuner "logged" the car today and said hmmmm not good look at this. Well..... OK I'm looking and :confused: Not sure what it all means he said lean and knocking a few times and says I should get another tune. Any idas? Sorry for the confusing post.
 

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Not sure where he's getting the lean statement. To make that call, you'd need a wideband or at least be output the 02 signal.

What you have displayed are the AF learning % at the different load/rpm ranges. With that said, all of your values are negative, which means the ECU is PULLING fuel out because it detected a RICH condition.

Keep in mind that is all based on closed loop driving; that is driving at sane person speeds with limited throttle input and change.

Now, for the comment of knock. Yes, your vehicle detected what it believes to be knock. This is noted because your ign. corr AK value went negative. But I'm also going to argue this one as well...

It did occur while making a full throttle pull, however....it occurred during your shift. I've fought this with my FXT. So far I've messed with tip in enrichment and the timing values at no/little load to clean it up.

My point though, is that it's not as likely to damage your engine as say a full load pull. But, it is pulling timing that does affect you for the duration of your pull, so end result is that the car will be sluggish to some degree.

Do you notice that sometimes you go full throttle she pulls really hard, but other times, it seems to hesitate / feel a little doggy?
 

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Discussion Starter #3
Thanks for the information. He did have a wide band AFR meter installed on my down pipe. I will try to get those numbers.

So if I am understanding you, unless my AFR is off, the tune looks OK?
 

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Its only 2 degrees FBKC, but it is during the pull James. I don't think that due to shifting. I know what your talking about though. You end up with a couple of cells of FBKC around a shift point. I'm sure its because the ECU is also looking at fast decceleration of the crank.

Anyhow, your AFR's would be good to know. You are already down to 14-15*, so I would drop timing any. So if your AFR's are proper, I'd be looking at your fuel choices, and if that is in line, I'd drop to 16 psi peak.

2* FBKC is the ECU saying "I'm a little to close for comfort to the knock threshold." Not a huge concern, but something I wouldn't ignore as a tuner. I'd dial it back a bit for safety factor.
 

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I'm sifting through some old logs where I experienced the issue in the past. I'd see a about a 1 entry delay (~330m/s) from when I logged throttle reopenning, to a bump in knock sum, and thus some FBKC.

It's pretty similar to what Nevada has in his log, but I could also see that as mid-pull knock.

Two ways I use to tell if it is throttle related.
1: Do a pull from 3K up, and never have a knock count increase.
2: Sit and idle at no load, keep jabbing the throttle and watch the knock sum number rise and rise.

With that said, if the other tuner would be willing to log your vehicle again, try the above and see if your knock sum number bumps up. Or maybe you have the full log file we can dig through that may have some other instances we can review.

Scott, take a second look at his load values versus his manifold pressure given he's on a VF48. It's late and I'm getting crossed eyed comparing this to other logs I've taken, but they seem a little low. I initially looked because the injector duty cycles seemed lower than I'd expect on a VF'ed FXT, but just figured there were aftermarket injectors. Then got to looking further...

Just back-calculated, it shows you only pushing 200g/s. Do you have an aftermarket intake or injectors that were tuned for?
 

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Discussion Starter #6
I just received an email from the guy who captured the info. He stated that my AFR was 12.0 to 12.2.
 

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I'm sifting through some old logs where I experienced the issue in the past. I'd see a about a 1 entry delay (~330m/s) from when I logged throttle reopenning, to a bump in knock sum, and thus some FBKC.

It's pretty similar to what Nevada has in his log, but I could also see that as mid-pull knock.

Two ways I use to tell if it is throttle related.
1: Do a pull from 3K up, and never have a knock count increase.
2: Sit and idle at no load, keep jabbing the throttle and watch the knock sum number rise and rise.

With that said, if the other tuner would be willing to log your vehicle again, try the above and see if your knock sum number bumps up. Or maybe you have the full log file we can dig through that may have some other instances we can review.

Scott, take a second look at his load values versus his manifold pressure given he's on a VF48. It's late and I'm getting crossed eyed comparing this to other logs I've taken, but they seem a little low. I initially looked because the injector duty cycles seemed lower than I'd expect on a VF'ed FXT, but just figured there were aftermarket injectors. Then got to looking further...

Just back-calculated, it shows you only pushing 200g/s. Do you have an aftermarket intake or injectors that were tuned for?
I think we got the rest of the story above James...

The main reason I didn't jump to shift knock is that its sustained through that particular gear pull.

IDC's are far too low for a VF48 at 17 psi at 5k rpm. Should be far higher than 66%. Now we know. I wouldn't be running 12:1 on pump gas on our motors. I run 12-12.5:1 eqv. on my EJ20, BUT, I run E85. Not enough safety factor on pump gas.

Even dropping AFR's down to 11.5:1, the IDC's are still quite low. I completely agree with you here James. Something doesn't seem right to me. I had my IDC's up to 83% on my TD04. Nevada, your IAT's must be quite high. What's the ambient temp? Are you running a hot air intake?
 

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Discussion Starter #9
Ambient air temps for this log were around 55 or so. I am running the stock airbox and intake to an STi TMIC.
 

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Can you list all of your mods...something doesn't seem right.
 

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Discussion Starter #11
STi Grimmspeed PnP exhaust manifolds
STi uppipe
VF48 turbo
Cobb catted down to full STi back
STi TMIC
Walbro 255 with stock injectors
one step colder plugs

I think that is it. As far as air temps it has been cool but I have the Subtle splitter in my garage wiating for the 02-03 scoop to install. Should be net few weeks.

I really appreciate the help.
 

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Tear/leak in the turbo inlet or aftermaf hose? Unless the MAF sensor is reading erroneous (dirt or going bad), or someone rescaled it incorrectly but I'd doubt that given you're on a the stock inlet setup.
 

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Discussion Starter #13
I guess I will be spending some time standing on my head and using a mirror. Is there an easy to check it or a common place they crack?
 

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I prefer to pressurize it. Do you have an air compressor by chance? I can show you what I made up, or even possibly ship you what I have to borrow if you need.
 

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I prefer to pressurize it. Do you have an air compressor by chance? I can show you what I made up, or even possibly ship you what I have to borrow if you need.
I do the same...
 

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I'll try to snap a shot today after work and post it up for you guys. In short, it's a 2" cast pipe cap (so that the OD works out to ~2.5") drilled and tapped for 1/4" (?) pipe thread. I then threaded a quick connect that will mate up to my air compressor. Just make sure you regulate the air down prior to connecting it.

It's also handy to have a spray bottle around to spritz things. Makes the leaks far more visible.
 

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^^That looks far too nice...:biggrin:

You can build a cheap one that will do the job for ~$10 at a hardware store. I just use a rubber drain/sewer coupler with a pvc end cap, drill a hole in the end cap and self tap a quick disconnect air fitting into it. This is assuming you have a pressure regulator on your air compressor.

I normally pressurize up to 20 psi, since thats how much boost I run on...
 
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