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Author Topic: B_lambts, Throttle Cut, Soft Limp, ME7.5 1.8T  (Read 557 times)
boim
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« Reply #15 on: May 21, 2020, 09:05:54 AM »

Dont do this.

But yes, it is possible it is your MAF if you keep seeing that MAF too low code

No, no longer with that BoV. It was try and error Cheesy

Current MAF just 2 months old and consistently reading 133 g/s on gear2 before getting cut.
 
Couldn't wait until weekend;
Did TIP check as I never done it before and it might be 17y.o. as well. Apperantly there is 2 quite big cuts there below Puck, seems rubbed down by the hot air from crankcase ventilation. Sealed it while waiting for the replacement arrive. Hope this is the culprit.
Plumbed back the N249.
Checked the DV seems stilll ok, try to push manually the valve still pushing back hard; but let's see whether i'll get check DV DTC later.
No chance to test yet.
« Last Edit: May 21, 2020, 09:16:58 AM by boim » Logged
boim
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« Reply #16 on: May 21, 2020, 09:10:28 AM »

--deleted this post, seems I accidenally quoted myself and posted, sorry Sad
« Last Edit: May 21, 2020, 09:13:45 AM by boim » Logged
boim
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« Reply #17 on: May 22, 2020, 05:48:57 AM »

Managed to pull - now I got 164 - 169ish MAF reading. Lifted up because of traffic - hesitation in one of runs due to traffic as well;Don't want to break the seal either Cheesy Darn that TIP leak!

Bunch of thanks Nyet! for insisting MAF reading problem, otherwise I would be lost again.

Wondering tho:
- what is the B_lambts active effect? I was suspecting it was a cause as cut happened after it's active - defintely wrong. Sorry, FR was too complicated to me and I only a car user.
- I was expecting 120ish g/s MAF (with no cut) as car spec was 150HP and all is stock except open air filter+N112 Delete (ESKONF & CWSLS update)+crank case ventilation to atmosphere (I took off the Puck, as it has no place at the moment). Why I got that 160ish MAF reading? forgot to mention that i have tightened the wg by 3 turns beside those 3 stuffs non stock.

--might be this topic needs to be moved to noob question now, as it's hardware issue instead of tuning--
« Last Edit: May 22, 2020, 06:23:24 AM by boim » Logged
boim
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« Reply #18 on: May 23, 2020, 12:43:06 AM »

B_Lambts

S4Wiki:
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LAMBTS
EGT enrichment tables:

  • KFLBTS_0_A - requested lambda for component protection when calculated EGT (tabgbts_w) is above TABGBTS, modified by FBSTABGM, DLBTS, and KFFDLBTS.
    FBSTABGM (0x150C2) - KFLBTS multiplier. Make sure you change the axis properly to represent your lowered TABGBTS. Again, not necessary if you have a properly scaled MAF. Also, all ones in most files.
    [KF]DLBTS and KFFDLBTS - lambts = KFLBTS + [KF]DLBTS*KFFDLBTS. Therefore, setting KFLBTS to 1 where you don't need it won't disable bts, you also have to set KFFDLBTS = 0 as well.[23] Note that Mbox has DLBTS (2D), not KFDLBTS (3D).[24]
    TABGBTS - Threshold for KFLBTS. Unless calculated EGTs are above this threshold, KFLBTS is ignored. You may have to lower TABGBTS if you have a scaled MAF, since calculated EGTs will be artificially low.

The result is "lambts"
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--> so the B_lambts is condition for enrichment/make the above active/not to cut the throttle: CMIIW.

2. MAF Reading

S4wiki:
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--
Also, you should always compare msdk_w (alpha-n estimated air flow) vs mshfm_w (measured airflow). If they are different, you will likely need to adjust WDKUGDN and the VE model in BGSRM accordingly. This will ensure that if you unplug the MAF or it fails, the car will run properly in alpha-n.
--
Scale MLHFM (constant throughout scale vs stock!) to get your idle and partial short term fuel trims (STFT) near zero and your WOT AFR to roughly match your requested AFR. Another good MLFHFM sanity check is to log ps_w vs actual boost at WOT - ps_w should generally be slightly below actual boost. If it is over, your MAF is probably overscaled, and if you are running the stock MAP and not a 5120[10] hack, you run the risk of maxing out ps_w, which is a bad thing (see below).
----------

---> will log msdk_w and ps_w to check whether my MAF sensor needs scaling as the above (it's ITM brand if I'm not mistaken, was best available here locally that time of purchase, not genuine nor bosch oem)
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fukenbroken
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mk4 1.8T AUM


« Reply #19 on: May 23, 2020, 12:55:15 AM »

Only bosch sensor will work properly.
As for bts, it's an enrichment based on calculated egt
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nyet
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« Reply #20 on: May 23, 2020, 12:56:05 AM »

---> so the B_lambts is condition for enrichment/make the above active/not to cut the throttle: CMIIW.
You're wrong. lambts has nothing to do with throttle cut, unless the same root problem triggered both. I have no idea how you decided based on the description you posted how lambts is connected to throttle cut.

Quote
---> will log msdk_w and ps_w to check whether my MAF sensor needs scaling as the above (it's ITM brand if I'm not mistaken, was best available here locally that time of purchase, not genuine nor bosch oem)

This is not something you should log to find out. You either got the right MAF or you didn't.

If the MAF you got isn't stock, you had better have a datasheet to go with it, or throw it away. It's useless. I have no idea how "its the best one i could find" makes any damn sense. It does not.
« Last Edit: May 23, 2020, 12:58:10 AM by nyet » Logged

ME7.1 tuning guide (READ FIRST)
ECUx Plot
ME7Sum checksum checker/corrrector for ME7.x

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 experience.
boim
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« Reply #21 on: May 23, 2020, 09:57:49 AM »

Thanks much Nyet, Fukenbroken - what knowledge I got here this time.

I did a run for mshfm_w vs msdk_w and ps_w vs plsol_w got as attached. And, yes, crappy MAF sensor - in some other high load high RPM (140-150ish g/s msdk_W)the reading became messy up and down, made me to lift up a bit to avoid limp mode due to hesitation.

A lot of chinese MAF product here and pretty difficult to get genuine BOSCH MAF, that's why I mentioned 'best I could find locally here' Anyway, I will find a new Bosch MAF before I move forward with tuning.

Thanks again!
« Last Edit: May 24, 2020, 03:29:40 AM by boim » Logged
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