Strange Idle Surging Shake Down

   #1  

mark4mike

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Hey All. I've been chasing a strange idle surging issue on my MK7 Alltrack. This issue has been on going for a couple months but I've never received any codes from it so basically just have a couple symptoms to go off of and process of elimination. The car is modified with a Walbro 525lph in tank pump, multiport injection (980cc), and ethanol content sensor among numerous other modifications. The car also drives completely fine, pulls great through redline, has never stalled or had fuel cuts under load or anything like that.

I used VCDS to look at High Pressure Fuel Specified and Actual. When I look at my values as the car idles, the specified amount seems to fluctuate between 46 bar and up to 60 bar, never remaining consistent. The actual still remaining close to specified. Is this normal? In the research I've done, it seemed that specified should remain at a consistent value and not fluctuate but I haven't been able to find a definitive answer. When I shut off the car and monitor the Actual fuel pressure, it does continue to go up to the low 60s bar which is to be expected.

What I've replaced and tested has lead me to believe it could be related to either fueling or tuning, but wanted to rule out what I can before I discuss with my tuner. I've replaced the PCV, EVAP Purge Valve, pre-cat O2/Wide-band sensor, intake manifold MAP sensor, pre-throttle body MAP sensor on the charge pipe, Spark plugs, and coil packs. I've smoke tested the car at the intake inlet and intake manifold and found no leaks and thoroughly looked at all fuel lines, connections, and injector seats and have found nothing. LPFP pressure is strong and consistent as well, and I've also done a compression test hitting 175-180 across all 4 cylinders.

The only current symptoms and oddities I've noted are:
-slightly rough idle surging with inconsistent rev dips, meaning no continuous pattern like you'd see with a vacuum leak.
-as idle surges you can hear a loud rattling coming from the HPFP
-VCDS shows that the specified fuel value is not constant and is constantly changing
-If I blip the throttle at idle, it smooths out to something more normal for a little while but will eventually start doing it again.

I've ordered a new updated revision HPFP and new cam follower to rule out any internal issues with it, however since I've never thrown a code for low fuel pressure I still have some degree of doubt that the HPFP is failing since under load everything looks and feels fine. It's just at idle and that rattle noise I hear as the idle surges along with the fluctuating specified high pressure values. Any other thoughts are very appreciated.

Here's a video from the engine bay of the rough idle and the noise the fuel pump makes when the idle surges:


And here's a video of the high pressure fuel specified and actual values at idle:

 
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   #2  

PetrolDave

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It's much easier to help if we know how your Alltrack is equipped and configured, so even if there are no fault codes please post an Auto-Scan
 
   #3  

mark4mike

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It's much easier to help if we know how your Alltrack is equipped and configured, so even if there are no fault codes please post an Auto-Scan

Hope this helps -

Code:
Monday,28,October,2024,18:55:41:44214
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 11 x64
VCDS Version: 24.7.1.0 (x64)  HEX-V2 CB: 0.4643.4
Data version: 20240919 DS356.3
www.Ross-Tech.com


VIN: 3VWM17AU6HM5XXXXX       License Plate:
Mileage: 185762km-115427mi   Repair Order:


Chassis Type: AU-VW37 (3Q0)
Scan: 01 03 08 09 15 16 17 19 22 42 44 52 5F 75

VIN: 3VWM17AU6HM5XXXXX        Mileage: 185762km-115427miles

01-Engine -- Status: OK 0000
03-ABS Brakes -- Status: OK 0000
08-Auto HVAC -- Status: OK 0000
09-Cent. Elect. -- Status: OK 0000
15-Airbags -- Status: OK 0000
16-Steering wheel -- Status: OK 0000
17-Instruments -- Status: Malfunction 0010
19-CAN Gateway -- Status: OK 0000
22-AWD -- Status: OK 0000
42-Door Elect, Driver -- Status: OK 0000
44-Steering Assist -- Status: OK 0000
52-Door Elect, Pass. -- Status: OK 0000
5F-Information Electr. -- Status: Malfunction 0010
75-Telematics -- Status: OK 0000
-------------------------------------------------------------------------------
Address 01: Engine (J623-CXBB)       Labels:. 06K-907-425-V1.clb
   Part No SW: 8V0 906 264 M    HW: 06K 907 425 B
   Component: 1.8l R4 TFSI  H13 4154
   Revision: --H13---    CVN: 899D91CC
   Coding: 311900122426002F0000
   Shop #: WSC 00066 790 00149
   ASAM Dataset: EV_ECM18TFS0208V0906264M 001003
   ROD: EV_ECM18TFS020_VW37.rod
   VCID: 46D5AB94082D265A257-8012
   VINID: 0E69DD0474651987450C91840896F4ADEC

No fault code found.
Readiness: 0010 1001

-------------------------------------------------------------------------------
Address 03: ABS Brakes (J104)       Labels:* 5Q0-907-379-ESP-V1.clb
   Part No SW: 5Q0 614 517 AQ    HW: 5Q0 614 517 AF
   Component: ESC           H62 0400
   Revision: 00000000    Serial number: 50907000000864
   Coding: 43FA6AA134230975407D030480C529C2562C9002C001943C00435050E009430000010312121212B435351919323200
   Shop #: WSC 01383 790 50316
   ASAM Dataset: EV_Brake1UDSContiMK100ESP 036010
   ROD: EV_Brake1UDSContiMK100ESP_036_VW37.rod
   VCID: 00597D8C6A89C86A5FB-8054

No fault code found.

-------------------------------------------------------------------------------
Address 08: Auto HVAC (J301)       Labels:| 5G0-907-426.clb
   Part No SW: 5GM 907 426 E    HW: 5GM 907 426 E
   Component: AC Manuell    H03 1801
   Revision: 00001K04 
   Coding: 02020004200100000000000000000002
   Shop #: WSC 01383 790 50316
   ASAM Dataset: EV_ACManueBHBVW37X 004134
   ROD: EV_ACManueBHBVW37X_004_VW37.rod
   VCID: 4ACD9FA41C35C23AC1F-801E

   Fresh air blower control module (front):

   A/C pressure/coolant temperature sensor:

No fault code found.

-------------------------------------------------------------------------------
Address 09: Cent. Elect. (J519)       Labels:. 5Q0-937-08X-V2.clb
   Part No SW: 5Q0 937 087 AN    HW: 5Q0 937 087 AN
   Component: BCM PQ37BOSCH 032 0223
   Revision: --------    Serial number: C86405041703HE Dataset Number: V03935261XH 0001
   Shop #: WSC 00066 790 00149
   ASAM Dataset: EV_BodyContrModul1UDSBosc 017002
   ROD: EV_BCMBOSCH_017.rod
   VCID: 074B66904FA7FF521E1-8052

   Wiper motor control module:
   Subsystem 1 - Part No SW: 5G1 955 119 A    HW: 5G1 955 119   Labels: 5QX-955-119-V1.CLB
   Component: WWS    170217  043 0551
   Serial number: 97022066170228092015
   Coding: 0E4DDD

1 Fault Found:
197379 - Lock Module for Central Locking; Rear Right
          B12DC 07 [00001000] - Mechanical Failure
          Intermittent - Confirmed - Tested Since Memory Clear


-------------------------------------------------------------------------------
Address 15: Airbags (J234)       Labels:| 5Q0-959-655.clb
   Part No SW: 5Q0 959 655 J    HW: 5Q0 959 655 J
   Component: AirbagVW20    010 0830
   Serial number: 003GCR07LEN. Dataset Number: 5GM003V____ 0044
   Coding: 8CCCFC00000000005000001AC24800000065
   Shop #: WSC 01383 790 50316
   ASAM Dataset: EV_AirbaVW20SMEVW37X 002144
   ROD: EV_AirbaVW20SMEVW37X_VW37.rod
   VCID: 47CBA6900F273F52DE1-8012

   Seat occupied recognition passenger side:
   Subsystem 1 - Part No SW: 4M0 959 339 B    HW: 4M0 959 339 B
   Component: BF-Gewichtss.  H13 0022
   Serial number: IBH000000000006TYQEQ
   Coding: 303135

   Crash sensor for side airbag: driver side:
   Subsystem 2 - Part No SW: -----------    HW: 480 000 903 17
   Component: SideSensor_Df  001 0887
   Serial number: 3570000000044314F126
   Coding: 2D2D2D

   Front Passenger's Side Airbag Crash Sensor:
   Subsystem 3 - Part No SW: -----------    HW: 480 000 903 17
   Component: SideSensor_Pf  001 0887
   Serial number: 35800000000E1214F12D
   Coding: 2D2D2D

   Rear Side Airbag Crash Sensor (on driver's side):
   Subsystem 4 - Part No SW: -----------    HW: 480 402 402 17
   Component: SideSensor_Dr  000 6149
   Serial number: 35100019D241965341E
   Coding: 2D2D2D

   Passenger side rear thorax airbag crash sensor:
   Subsystem 5 - Part No SW: -----------    HW: 480 401 003 17
   Component: SideSensor_Pr  000 6149
   Serial number: 35200019F25187D481A8
   Coding: 2D2D2D

   Crash sensor for front airbag: driver side:
   Subsystem 6 - Part No SW: -----------    HW: 480 401 603 17
   Component: FrontSensor_D  001 6149
   Serial number: 3550002BD24F384403FB
   Coding: 2D2D2D

   Crash sensor for front airbag: front passenger side:
   Subsystem 7 - Part No SW: -----------    HW: 480 401 603 17
   Component: FrontSensor_P  001 6149
   Serial number: 3560002C12439CE4B114
   Coding: 2D2D2D

No fault code found.

-------------------------------------------------------------------------------
Address 16: Steering wheel (J527)       Labels:| 5Q0-953-549.clb
   Part No SW: 5Q0 953 507 FT    HW: 5Q0 953 549 F
   Component: Lenks. Modul  003 0140
   Revision: --------    Serial number: 04031708491112
   Coding: 0400
   Shop #: WSC 00000 000 00000
   ASAM Dataset: EV_SMLSKLOMQB 020002
   ROD: EV_SMLSKLOMQB_018_VW37.rod
   VCID: 0D4754B82DDB950224D-8058

No fault code found.

-------------------------------------------------------------------------------
Address 17: Instruments (J285)       Labels:| 5G0-920-XXX-17.clb-SRI3
   Part No SW: 5G1 920 840 B    HW: 5G1 920 840 B
   Component: KOMBI         244 8311
   Coding: 0BB51005A180CF0502086A001000000000000000
   Shop #: WSC 00066 790 00149
   ASAM Dataset: EV_DashBoardVDDMQBAB 009051
   ROD: EV_DashBoardVDDMQBAB_009_VW26.rod
   VCID: 26150B14A86DC65A057-8072

1 Fault Found:
16777020 - Function Restricted due to Interrupted Communications
          U1110 00 [00001000] - -
          [BAP_TEL_0x28 keine Kommunikation]
          Intermittent - Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Priority: 6
                    Fault Frequency: 23
                    Reset counter: 9
                    Mileage: 170676 km
                    Date: 2024.05.25
                    Time: 07:22:40


-------------------------------------------------------------------------------
Address 19: CAN Gateway (J533)       Labels:| 3Q0-907-530-V1.clb
   Part No SW: 3Q0 907 530 B    HW: 3Q0 907 530 B
   Component: GW MQB Mid    514 5286
   Serial number: 28041700840729 Dataset Number: V03935252FW 0001
   Coding: 0101000870085900FB0020080A0F00000001050000000000000000000000
   Shop #: WSC 00066 790 00067
   GVL: 01D03C0000000000400C00008000480000000000000000000000000000000000
   ASAM Dataset: EV_GatewNF 013020
   ROD: EV_GatewNF_VW37.rod
   VCID: 2E05F334809D8E1AFD7-807A

   Generator:

   Multifunction steering wheel control module:
   Subsystem 2 - Part No SW: 5G0 959 442 P    HW: 5G0 959 442 P  Labels: 3C8-959-537.CLB
   Component: E221__MFL-DC1  H17 0103
   Serial number: 29170000180040127037
   Coding: 30FFFF

No fault code found.

-------------------------------------------------------------------------------
Address 22: AWD (J492)       Labels:| 0CQ-907-554-V1.clb
   Part No SW: 0CQ 907 554 H    HW: 0CQ 525 130
   Component: Haldex4Motion H52 7083
   Serial number: HA1-00002.12.16 Dataset Number: v1260x015G0 0000
   Coding: 0001
   Shop #: WSC 00066 790 00149
   ASAM Dataset: EV_AllWheelContrHA1VW37X 004013
   ROD: EV_AllWheelContrHA1VW37X_004_VW37.rod
   VCID: 4ACD9FA41C35C23AC1F-801E

No fault code found.

-------------------------------------------------------------------------------
Address 42: Door Elect, Driver (J386)       Labels:| 5QX-959-X93-42.clb
   Part No SW: 5Q0 959 593 E    HW: 5Q0 959 593 B
   Component: TSG FS        020 0041
   Serial number: 1204170605081B Dataset Number: V03935249RC 0001
   Coding: 003A03200000020000000000
   Shop #: WSC 01383 790 50316
   ASAM Dataset: EV_DCUDriveSideEWMAXKLO 006003
   ROD: EV_DCUDriveSideEWMAXKLO.rod
   VCID: 43D3B2803B1F1372029-8016

   Rear Driver Side Door Control Module:
   Subsystem 1 - Part No SW: 5Q4 959 811 D    HW: 5Q4 959 811 D  Labels: 5QX-959-81X-V1.CLB
   Component: Fond FHSG DRV  007 0002
   Serial number: 00000000000006027479
   Coding: 011000

No fault code found.

-------------------------------------------------------------------------------
Address 44: Steering Assist (J500)       Labels:| 5Q0-909-144.clb
   Part No SW: 5QM 909 144 A    HW: 5QM 909 144 A
   Component: EPS_MQB_ZFLS  171 1072
   Dataset Number: V03935245KL 0001
   Coding: 8102
   Shop #: WSC 00066 790 00149
   ASAM Dataset: EV_SteerAssisMQB 013144
   ROD: EV_SteerAssisMQB_013.rod
   VCID: 4FFB8EB0E757E712961-801A

No fault code found.

-------------------------------------------------------------------------------
Address 52: Door Elect, Pass. (J387)       Labels:| 5QX-959-X92-52.clb
   Part No SW: 5Q0 959 592 E    HW: 5Q0 959 592 B
   Component: TSG BFS       020 0041
   Serial number: 120417060509MN Dataset Number: V03935249RE 0001
   Coding: 003A03200400020000000000
   Shop #: WSC 01383 790 50316
   ASAM Dataset: EV_DCUPasseSideEWMAXKLO 006003
   ROD: EV_DCUPasseSideEWMAXKLO.rod
   VCID: 42DDB78424051A7A09F-8016

   Rear Passenger Door Control Module:
   Subsystem 1 - Part No SW: 5Q4 959 812 D    HW: 5Q4 959 812 D  Labels: 5QX-959-81X-V1.CLB
   Component: Fond FHSG PSG  007 0002
   Serial number: 00000000000005976744
   Coding: 091000

No fault code found.

-------------------------------------------------------------------------------
Address 5F: Information Electr. (J794)       Labels:| 5G0-035-MIB-STD2.clb
   Part No SW: 3Q0 035 844 A    HW: 3Q0 035 844 A
   Component: MU-S-S-US     710 0753
   Serial number:                Dataset Number: V03935258KM 0001
   Coding: 02730200FF00000051220001001808009F0108D40120010002
   Shop #: WSC 00066 790 00067
   ASAM Dataset: EV_MUStd4CDELP 001001
   ROD: EV_MUStd4CDELP_VW26.rod
   VCID: 2D07F4388D9BF502C4D-8078

   Display and control head 1 for information electronics:
   Subsystem 1 - Part No SW: 3G0 919 605 H    HW: 3G0 919 605 H
   Component: ABT_Std-2  H53 1031
   Serial number: VWZ8Z9TJW02CX9   

1 Fault Found:
0020 - Tuner for Satellite Radio
          B11CF 53 [00001001] - Deactivated
          Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Priority: 4
                    Fault Frequency: 1
                    Reset counter: 213
                    Mileage: 170292 km
                    Date: 2024.05.21
                    Time: 09:58:39

                    Voltage terminal 30: 13.9 V
                    SDARS_tuner_status_2-Satellite radio antenna status: electrically OK
                    SDARS_tuner_status_2-Channel selection for satellite radio: 0
                    SDARS_tuner_status_2-Audio Signal: available.
                    SDARS_tuner_status_2-Antenna current: 140 mA
                    SDARS_tuner_status_2-Reception quality: optimum_signal
                    SDARS_tuner_status_2-Satellite radio tuner: pre-activation status: 05
                    SDARS_tuner_status_2-Satellite radio tuner: pre-activation value: 05


-------------------------------------------------------------------------------
Address 75: Telematics (J949)       Labels:| 5QE-035-285.clb
   Part No SW: 5QE 035 285 A    HW: 5QE 035 285 A
   Component: OCULowMQBUS   007 0570
   Dataset Number: V03935236TB 0001
   Coding: 02730202C2821A017F1E06020000
   Shop #: WSC 00066 790 00067
   ASAM Dataset: EV_OCULowMQB 001006
   ROD: EV_OCULowMQB.rod
   VCID: 43D3B2803B1F1372029-8016

No fault code found.

End----------(Elapsed Time: 01:15, VBatt start/end: 12.2V/12.3V)-----------
 
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   #4  

Uwe

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   #5  

mark4mike

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So what fault codes did this ECU have before you recently cleared them?

-Uwe-

They were codes that showed up from doing the compression test. These readiness ones appear to pertain to the O2, SAI, and Cat from the software I'm guessing
 
   #6  

Uwe

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These readiness ones appear to pertain to the O2, SAI, and Cat from the software I'm guessing
Readiness codes only revert to "Failed or Incomplete" when fault codes are cleared.

-Uwe-
 
   #7  

mark4mike

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Readiness codes only revert to "Failed or Incomplete" when fault codes are cleared.

-Uwe-

I've definitely put more than enough miles on the car since doing the compression test and clearing those codes. Any suggestions on how to proceed?
 
   #8  

mark4mike

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Ended up contacting my tuner and will provide an update. My new pump and cam roller arrive today which I'll try to get installed this evening after the trick or treaters are done and will provide an update regardless. I've come across a few posts of individuals having issues with the internal FPR on the old versions as well as some with issues with the piston failing or some internal leaking. I have my doubts this is my issue, but with mine having 115k+ miles on it and it having been revised a couple times, I'll call it preventative maintenance.
 
   #9  

mark4mike

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I went through the UDS Automatic Test Procedure under [Basic Settings]. I was able to get SAI readiness set, however when I got to the test for Oxygen sensor aging test: bank 1 upstream of CAT, it ran for a couple minutes and then set the Operating Instruction to "Cancel" and Timed out the test. I tried running the same test again individually but it produced the same results. The upstream O2 is the one I've replaced but I'm guessing it's tune related. I did notice that as it held the engine speed during the upstream O2 test that the rpms were bouncing a bit. I'm not sure if that's to be expected or not for that test but was just something I noticed. I haven't heard from the tuner yet but wanted to give an additional update.

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