Please check my boost/maf logs

Judson

Veteran Member
Joined
Jan 18, 2001
Location
Cheyenne, WY
TDI
2001 Jetta
Hi folks -

Looking for feedback on some data logging.... All logs gathered at full temp.

Thank you very much in advance!

Jud.

First, boost: RPM, Requested, Actual.

903 999.6 754.8
1029 999.6 754.8
966 1040.4 754.8
1092 1030.2 765
1134 1050.6 775.2
1386 1132.2 785.4
1449 1162.8 805.8
1638 1183.2 836.4
1827 1224 887.4
2037 1254.6 989.4
2226 1254.6 1142.4
2415 1254.6 1305.6
2583 1254.6 1428
2814 1264.8 1438.2
2814 1030.2 1346.4
2415 1009.8 1091.4
1974 999.6 989.4
1596 1111.8 969
1701 1336.2 1009.8
1785 1346.4 1091.4
1869 1203.6 1213.8
1932 1122 1275
1953 1060.8 1224
1953 1009.8 1132.2
1974 999.6 1030.2
1869 999.6 969
1827 999.6 928.2
1743 999.6 907.8
1428 999.6 887.4
1113 999.6 867
987 999.6 836.4
924 999.6 816
882 999.6 795.6
903 999.6 785.4
903 999.6 785.4
903 999.6 785.4
903 999.6 775.2
903 999.6 775.2
945 1009.8 765
1197 1009.8 765


Now the MAF:

903 850 440
882 850 450
861 850 440
966 850 425
987 850 445
1008 850 445
1008 850 450
1008 850 445
924 850 450
903 850 450
903 850 455
882 850 445
1050 850 390
1134 850 435
1113 850 455
1050 850 445
1029 850 445
1029 850 445
1029 850 445
1008 850 450
1008 850 445
1092 850 430
1197 850 445
1281 850 450
1323 850 450
1344 850 460
1365 850 450
1344 850 465
1302 850 455
1281 850 445
1239 850 460
1197 850 455
1218 850 460
1260 850 475
1365 850 455
1512 850 475
1638 850 505
1743 850 545
1827 850 610
1953 850 685
2037 850 735
2163 850 760
2268 850 775
2352 850 765
2016 850 610
1512 850 530
1365 850 495
1365 850 530
1428 850 525
1491 850 550
1554 850 555
1638 850 600
1701 850 630
1743 850 650
1785 850 650
1806 850 640
1827 850 640
1827 850 620
1848 850 605
1848 850 625
1848 850 605
1827 850 590
1806 850 580
1806 850 560
1764 850 545
1722 850 510
1701 850 495
1638 850 475
1596 850 470
1533 850 460
1134 850 510
966 850 465
903 850 460
 

wonneber

Top Post Dawg
Joined
Oct 12, 2011
Location
Monroe, NY, USA
TDI
2014 Jetta Sportwagen, 2014 Tiguan,2003 Jetta 261K Sold but not forgotten
What block was the 'Now the MAF:' ??
850 across the range seems odd.
 

Judson

Veteran Member
Joined
Jan 18, 2001
Location
Cheyenne, WY
TDI
2001 Jetta
Hey wonneber that was engine-measuring blocks-channel 3.

Just did some reading over at myturbodiesel: maf values should roughly match?!

This maf is only about a two and a half years old (replaced 6/10/16), and is a good Bosch one so if it's bad it's surprising.

Update: unplugged the maf and can't tell the difference. Still pulls right to redline, still bogs down off idle. So weird.
 
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wonneber

Top Post Dawg
Joined
Oct 12, 2011
Location
Monroe, NY, USA
TDI
2014 Jetta Sportwagen, 2014 Tiguan,2003 Jetta 261K Sold but not forgotten
I thought so, the N75 was missing.
From Ross-Tech:
Group 003 (EGR)
Engine rpm: 870 - 950
Air mass drawn in (specified): 230 - 370 mg/H
Air mass drawn in (actual): 230 - 370 mg/H
EGR vacuum solenoid duty cycle: 40 - 75 %

In theory they should match, but there always is a lag factor.
Same for the boost.
One of the logging guru's will have to comment about the 850 not changing.
It may be a default number or such.
 

UhOh

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS
Please use the logging guidelines that Malone goes by. Nifty is that they also have a nice drag and drop graphing function, which you can get a visual on what's happening: I Like seeing raw data [when proper logging is done], but graphs are also nice.
 

Judson

Veteran Member
Joined
Jan 18, 2001
Location
Cheyenne, WY
TDI
2001 Jetta
Hey UhOh, I'll do that - they're on a different laptop, so I'll have to snag them later, then upload the graph/take new logs or something.

I went by the myturbodiesel MAF troubleshooting guidelines. According to them, under 3000 RPMS, specified and actual should be close. That my MAF is stuck at 850 despite the RPM means it's bad. A Pierburg and the metalnerd bits will arrive tomorrow night.
 

jimbote

Certified Volkswagen Nut
Joined
Jul 10, 2006
Location
spiral arm, milky way (aka central NC)
TDI
Tacoma 4x4 converted to TDI
maf 850 requested is normal for egr deleted tunes... looks to be lagging a little at lower rpm's ... check all your vacuum lines, under basic settings go to idle boost regulation and peek under the hood as the n75 cycles the vnt actuator... should have smooth quick movement from full stop to full open ... if it seems sluggish swap to the egr solenoid... your n75 could be rust contaminated... if movement is still sluggish with the swapped n75 and confirmed good vac lines move on to checking the actual vnt mechanism for sticking
 
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Judson

Veteran Member
Joined
Jan 18, 2001
Location
Cheyenne, WY
TDI
2001 Jetta
Hey Jimbote -

Good to know.

The problem is that the N75 is new, the turbo is new, vacuum lines are new, vacuum pump is new, injectors are new... Hell just about everything is new. And the exact same symptoms existed before and after all of this work.

So, this is about my last possibility. Unplugging the maf makes no difference than plugging it in too. - it's all I have to go on now.
 

Nevada_TDI

Top Post Dawg
Joined
Aug 17, 2008
Location
Reno, sort of...
TDI
2001 Jetta TDI
It looks as though your ECU has a tune programmed into it and I see you have a Stage 4 tune, so that answers that. I was going to suggest changing your MAF, but you say it makes no difference. You do mention a new turbo, so I wonder if the actuator arm was not set correctly. Please run a N75% log with requested/actual boost numbers, so we can see what your actuator is doing at WOT.
 

Judson

Veteran Member
Joined
Jan 18, 2001
Location
Cheyenne, WY
TDI
2001 Jetta
Hey Nevada_TDI -

I've got a new Pierburg MAF coming by tomorrow cob. I am hoping it makes a difference.

I've thought that it's possible the actuator arm is not set correctly, but since this symptom existed also during my VNT15, I've considered this a low probability.

I'll run some logs again before and after the new MAF and post 'em here.

Thanks a bunch everyone!

Jud.
 
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wonneber

Top Post Dawg
Joined
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Location
Monroe, NY, USA
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2014 Jetta Sportwagen, 2014 Tiguan,2003 Jetta 261K Sold but not forgotten
Judson
What is the problem you are looking into? Maybe I missed it.
 

Judson

Veteran Member
Joined
Jan 18, 2001
Location
Cheyenne, WY
TDI
2001 Jetta
OK here is the morning MAF log, before changing out the MAF. Full power runs, full temp.

Sorry about the thumbnail. Having problems with picture uploads this morning (required flash), and then finding the medium and/or large URL to the pic.



Wonneber - having severe issues getting off the line. Bogging down immediately, acting like it's flooding if I even so much as push the accelerator a little too much. This is highly dangerous, as if I'm not absolutely careful, I have no power as I accelerate through an intersection, meaning if anybody came barreling through a red light, I'd be helpless. Makes driving around time very stressful and a ton of work to very carefully work the clutch/accelerator.

It's been going on for about a year and a half, both before and after a metric stuffload of changes. About everything is new, on purpose and by design, not to fix this issue alone, and even the MAF is only 1.5 years old or so. i mean, every vacuum line, vacuum pump, turbo, intake, N75, so on and so forth.

Unplugging the MAF doesn't make a difference, so I believe's it's essentially dead, so this is what I'm going on. A new MAF will be coming this afternoon, so I'll plug that in and log another run.
 
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UhOh

Top Post Dawg
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Dec 24, 2014
Location
PNW
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2000 & 2003 Golf GLS
Again, please refer to Malone's guide on logging. There are several logs you should be running to fully present/assess how things are performing.

Another neat thing with their site is that when you upload your data (drag-and-drop) you can grab the link that is created when your data is graphed (also will allow referring to the raw data, which I like to see).
 

Judson

Veteran Member
Joined
Jan 18, 2001
Location
Cheyenne, WY
TDI
2001 Jetta
OK, latest log, first attempt at this. Sadly, after WOT run, very loud high pitch whine coming from engine. RPM-related, remained even if clutch pushed in. Diagnosing, but it's not a good sound. All boost tubes in place and look good. Whine louder from above engine, hardly any whine from below. Sigh.

 

Judson

Veteran Member
Joined
Jan 18, 2001
Location
Cheyenne, WY
TDI
2001 Jetta
Yeah, just did that at the advice of my mechanic. Didn't make a difference.

Honestly, sounds to me like it's coming right from the injection pump...!!! ????
No whine from below at all. But he believes that it's the output side of the turbo that's machining itself.
A new VNT17, no less. He may come up and take a look in person. I clearly can't drive it to his place.
 
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Judson

Veteran Member
Joined
Jan 18, 2001
Location
Cheyenne, WY
TDI
2001 Jetta
Hey Jimbote -

Talked with Jeff - you're right, unplugged the MAF should run better if the MAF was bad, as he put in a stock program for MAF-less situations.

He also says that the vendor I received my turbo from has been known to use Chinese turbos. Guess we'll see if I get a refund.

Needless to say I'll only be getting stuff from IDParts, or via my mechanic in the future. At least my mechanic will fully warrantee stuff - install and all.
 

Judson

Veteran Member
Joined
Jan 18, 2001
Location
Cheyenne, WY
TDI
2001 Jetta
If I was the guy doing all of the work, then yes, I'd buy/install myself. But I'm not. There are some jobs I leave to people with 1000x more hours working on cars than myself, and there are some jobs I can do myself without effing anything up, and can easily recover from if I do.

I have learned to never underestimate decades of experience of wrenching versus a shade tree mechanic's skills.
 

jmchugh588

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Jun 19, 2015
Location
texas
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golf alh, audi a4, vw transporter
Hi, sorry to bring up old thread but did you ever find out what was causing your car to bog down?. Having a exact same problem, my maf is also requesting 850 all the time
 
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