As above, the engine continues to run but stops on occaision, vcds indicates low pressure on the fuel rail, had this previously over the winter but it seemed to clear itself, the info at that time was a low pressure pump or valve proble, can't remember which, 

Anyone any suggestions, its a 2 litre 140(up to 168) diesel with a dtuk box fitted - I  will try again tomorrow with the box removed!

Where is this item(valve/pump) on the engine?

Fuel filter needing changed? ... had that on other diesels, where the servicing agent claimed the filter had been changed (and paid for,) but infact when looking at the filter it was still grubby, choked with gunge and full of water ...... 

 

New filter ... problem solved.

 

Worth a check.

Edited 26 June, 20214 yr by TruckbusUK
hit return too soon.

^  could be, just looked at old service sheets/bills, last done 2019 58k now done 71k with service in april  -  seems unlikely, but i'll have a look tomorrow!

Try driving the car with the MAF plug removed, I have the same symptoms with my 1.6tdi - when pulling away unless careful the engine drops way down to 500 rpm due to poor fueling.

 

With MAF plug removed, default values are used. It's a simple test that doesn't take effort. 

What/where is the MAF plug?

Just opened the fuel filter canister, its clean, as is the filter element, reassembled it, primed the cannister as recommended, still the same.

No carista message or VCDS message either, looks like a short trip is due! - then a rescan!

Tried it this morning, still the same if not worse, attached the vcds log - any suggestions? - replace low pressure sensor?

 

Monday,28,June,2021,10:26:07:34756
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 10 x64
VCDS Version: 21.3.0.0 (x64)
Data version: 20210226 DS325.0
www.Ross-Tech.com

VIN: TMBMD75LXD6090262   License Plate: ME 1
Mileage: 114000km-70836mi   Repair Order: 

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------

                Address 01: Engine       Labels: 03L-906-018-CFF.clb
Control Module Part Number: 03L 906 018 QL    HW: 03L 907 309 AG
  Component and/or Version: R4 2,0L EDC   H25 4785
           Software Coding: 00190012042700080000
            Work Shop Code: WSC 33361 790 00056
              ASAM Dataset: EV_ECM20TDI01103L906018QL 003004 (SK35)
                       ROD: EV_ECM20TDI01103L906018QJ.rod
                      VCID: 042966D98F9CDBABE7-8050
4 Faults Found:

5211 - Fuel Rail/System Pressure 
          P0087 00 [096] - Too Low
          Intermittent - Not Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 2
                    Fault Frequency: 1
                    Mileage: 113997 km
                    Date: 2021.06.28
                    Time: 09:45:47

                    Engine RPM: 3976.00 /min
                    Normed load value: 99.6 %
                    Vehicle speed: 63 km/h
                    Coolant temperature: 32 °C
                    Intake air temperature: 19 °C
                    Ambient air pressure: 1010 mbar
                    Voltage terminal 30: 14.380 V
                    Unlearning counter according OBD: 40
                    Fuel temperature: 16.8 °C
                    Mean injection quantity: 49.98 mg/stroke
                    Rail pressure regulation: status-Bits 0-7: 5
                    Fuel high-pressure: actual value: 1.3137e+006 hPa
                    High fuel pressure: specified value: 1.7928e+006 hPa
                    Pressure control valve adaptation factor: 0.8408
                    Fuel level: 45.00 l

5229 - Fuel Rail/System Pressure 
          P0088 00 [096] - Too High
          Intermittent - Not Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 2
                    Fault Frequency: 1
                    Mileage: 114001 km
                    Date: 2021.06.28
                    Time: 09:56:10

                    Engine RPM: 0.00 /min
                    Normed load value: 0.0 %
                    Vehicle speed: 0 km/h
                    Coolant temperature: 69 °C
                    Intake air temperature: 21 °C
                    Ambient air pressure: 1010 mbar
                    Voltage terminal 30: 11.880 V
                    Unlearning counter according OBD: 40
                    Fuel temperature: 19.3 °C
                    Mean injection quantity: 0.00 mg/stroke
                    Rail pressure regulation: status-Bits 0-7: 4
                    Fuel high-pressure: actual value: 539600 hPa
                    High fuel pressure: specified value: 280000 hPa
                    Pressure control valve adaptation factor: 0.8721
                    Fuel level: 44.00 l

5244 - Fuel Pressure Sensor (G247) 
          P0193 00 [167] - Short to Plus
          MIL ON - Not Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 2
                    Fault Frequency: 1
                    Mileage: 114004 km
                    Date: 2021.06.28
                    Time: 10:18:44

                    Engine RPM: 0.00 /min
                    Normed load value: 0.0 %
                    Vehicle speed: 0 km/h
                    Coolant temperature: 79 °C
                    Intake air temperature: 30 °C
                    Ambient air pressure: 1010 mbar
                    Voltage terminal 30: 12.100 V
                    Unlearning counter according OBD: 40
                    Engine status: COENG_READY
                    Engine status-Test_Program_Co Eng st COMPU VERB UBYTE: 1

5242 - Fuel Pressure Sensor (G247) 
          P0191 00 [237] - Implausible Signal
          MIL ON - Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 2
                    Fault Frequency: 1
                    Mileage: 113997 km
                    Date: 2021.06.27
                    Time: 09:47:25

                    Engine RPM: 0.00 /min
                    Normed load value: 0.0 %
                    Vehicle speed: 0 km/h
                    Coolant temperature: 43 °C
                    Intake air temperature: 20 °C
                    Ambient air pressure: 1000 mbar
                    Voltage terminal 30: 12.700 V
                    Unlearning counter according OBD: 40
                    Engine status: COENG_FINISH
                    Engine status-Test_Program_Co Eng st COMPU VERB UBYTE: 5

Readiness: 1 1 0 0 0 

Log-ME 1-TMBMD75LXD6090262-114000km-70836mi.txt

1 hour ago, Frenchtone said:

5242 - Fuel Pressure Sensor (G247) 
          P0191 00 [237] - Implausible Signal

Well, if a sensor throws an "implausible signal" error, I would tend to suspect it of being the actual fault.

Does the tuning box connect to the fuel rail? (my 2010 2.0tdi came with a DTUK that used to do this)

 

Try removing the tuning box and see how the car runs. 

 

MAF sensor location? Follow the air intake and you'll find the sensor in the plumbing between the battery and the head. 

Thanks, yes it does, I disconnected it before lunch , plugged the over ride plug in, went for a drive all ok, no error messages. 

opened up the box, traces of water droplets on the inside, dried it out, just about to go for a run with it reconnected as it could be the droplets shorting something under the 'chips' or it could be the box is knacked

Edited 28 June, 20214 yr by Frenchtone

Ok, my problem obviously was slight ingress of water into the box, just driven 15 miles with lots of gear changes, no problems, I'll reopen the box and run a smear of silicone grease around the joints - that should hopefully waterproof the box contents!!

Should have adhered to my longtime mantra, 'Keep it simple stupid' otherwise known as the KISS principle!!

Edited 29 June, 20214 yr by Frenchtone