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Author Topic: Fueling Issues - 1.8T ME7.5  (Read 20474 times)
kenmac
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« on: January 16, 2012, 09:30:16 PM »

Been working on a tune for some time now and I'm trying to work out a fueling issue in the higher rpms.  As you can see in the graph below, suddenly around 4200 rpm, the ecu begins dumping fuel.  The desired AFR even drops so low that it bottoms out the actual AFR.  Can anyone provide some assistance with troubleshooting this problem with me?

I haven't toyed too much with the fueling yet other than KRKTE, which I've zero'd out my trims with.  But I've borrowed the following maps from the TT225 since I'm running TT225 injectors (Bosch 386cc) and the TT225 MAF:
-TVUB
-MLHFM
-KFMLDMN
-KFKHFM
-FKKVS

Hardware:
K04-001 turbo
TT225 MAF
TT225 386cc injectors
Eurojet 'race' FMIC
Forge 007 Diverter Valve
2.5" Magnaflow DP+Catback Exhaust
N249 Delete
SAI Delete



Also attached my WinOLS file.

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airtite
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« Reply #1 on: January 16, 2012, 11:03:50 PM »

I dont see egt's logged maybe egts are exceeding 950degreeC and the ecu is dumping fuel too cool egt's?
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TheDSI
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« Reply #2 on: January 17, 2012, 04:57:15 AM »

your fueling is completly wrong like I said here .

->http://nefariousmotorsports.com/forum/index.php?topic=1272.msg11967#msg11967
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kenmac
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« Reply #3 on: January 17, 2012, 08:36:09 AM »

Correct me if I'm wrong, but the VW 1.8T does not carry any EGT sensors.  Are we somehow substituting real EGT information using the rear O2 cat temperature?

My LAMFA is stock.  I expected to tweak it a bit, but I'm trying to understand the cause of the sharp drop into rich territory before I do so.
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phila_dot
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« Reply #4 on: January 17, 2012, 08:39:08 AM »

Correct me if I'm wrong, but the VW 1.8T does not carry any EGT sensors.  Are we somehow substituting real EGT information using the rear O2 cat temperature?

My LAMFA is stock.  I expected to tweak it a bit, but I'm trying to understand the cause of the sharp drop into rich territory before I do so.

EGT for BTS is modeled, not actual reading from EGT sensor. What do your BTS tables look like? How are your CF's?
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kenmac
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« Reply #5 on: January 17, 2012, 11:56:14 AM »

EGT for BTS is modeled, not actual reading from EGT sensor. What do your BTS tables look like? How are your CF's?

I believe all of my BTS maps are untouched, stock.  Are there any particular ones I should focus on first?  I am going to read up on this in the funktionsrahmen.

Now that you mention CF's... they're rather high. -3, -6, -3, -8.25  and then they lowered to -2.25, -5.25, -5.25, -6.75 after the richness kicked in.  Next on my list was to tune KFZW and KFZW2, however, I'm surprised to see that under the stock timing map, I would still see high CFs.  I was under the impression that the stock timing map was pretty conservative.

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nyet
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WWW
« Reply #6 on: January 17, 2012, 12:06:33 PM »

http://s4wiki.com/wiki/Tuning#Fueling

Tongue
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ME7.1 tuning guide
ECUx Plot
ME7Sum checksum
Trim heatmap tool

Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your ex
kenmac
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« Reply #7 on: January 17, 2012, 01:19:10 PM »


Yup.  I think I know that section of your wiki by heart now.  I think only now it's starting to make a little sense.  Sorry, I'm a bit of a fueling newbie at the moment.
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kenmac
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« Reply #8 on: January 17, 2012, 03:33:20 PM »


Here's the same log, but also including CFs.  Looks like it's possible that the CFs are causing BTS to correct fueling.  What table controls this?

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TheDSI
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« Reply #9 on: January 17, 2012, 05:28:00 PM »

[KF]DLBTS and KFFDLBTS
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phila_dot
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« Reply #10 on: January 17, 2012, 05:34:13 PM »

IMO you should prevent the real issue by getting your CF's in check instead adjusting these maps.

It sounds like you have alot of work to do regarding fueling and timing.
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New2Tune
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« Reply #11 on: January 17, 2012, 06:15:46 PM »


Now that you mention CF's... they're rather high. -3, -6, -3, -8.25  and then they lowered to -2.25, -5.25, -5.25, -6.75 after the richness kicked in.  Next on my list was to tune KFZW and KFZW2, however, I'm surprised to see that under the stock timing map, I would still see high CFs.  I was under the impression that the stock timing map was pretty conservative.



How much load are you running?  I'm assuming its considerably higher than stock.  If that is the case then the load axis on the stock timing map only goes up to say 140% load.  If you don't modify the timing maps then you're trying to use the same ign advance at all loads greater than 140%.  The stock value at 140% load, 4500 rpm is too high for 190% load 4500 rpm unless you've got awesome fuel.
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kenmac
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« Reply #12 on: January 17, 2012, 11:43:51 PM »

How much load are you running?  I'm assuming its considerably higher than stock.  If that is the case then the load axis on the stock timing map only goes up to say 140% load.  If you don't modify the timing maps then you're trying to use the same ign advance at all loads greater than 140%.  The stock value at 140% load, 4500 rpm is too high for 190% load 4500 rpm unless you've got awesome fuel.

You're absolutely right.  I just set up a new KFZW(2) with a taller load axis and configured the values appropriately.  I'll log this on the way to work in the morning.  Hope there's no traffic for my 3rd gear pull. Smiley
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airtite
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« Reply #13 on: January 18, 2012, 12:16:15 AM »

any chance you can post what your modified KFZW looks like?
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kenmac
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« Reply #14 on: January 18, 2012, 12:28:21 AM »

any chance you can post what your modified KFZW looks like?

It's essentially the KFZW(2) from the TT225.  I'm using this as a starting point since my engine is fairly identical at this point.  The load axis goes up to 185.

8N0906018CB
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