'FSI Fuel Rail Pressure' - Desperate
- Thread starter Jeremy
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BigBang
Active Member
I will answer myself. Yes it is as I said. That means issue with the pressure itself or pressure sensor.
1. If it reads correct pressure from LP pump I think it has really low possibility that it doesn't show high pressure correctly, but it is one posibility.
2. HP pump faulty - I would expect even badly worn/faulty pump would create at least some pressure (> than 3.8 bar).
3. Pressure regulator faulty - stuck? I don't know how the FSI is constructed.
4. Leaking injector - I would assume it would be acting similar as faulty HP pump.
1. If it reads correct pressure from LP pump I think it has really low possibility that it doesn't show high pressure correctly, but it is one posibility.
2. HP pump faulty - I would expect even badly worn/faulty pump would create at least some pressure (> than 3.8 bar).
3. Pressure regulator faulty - stuck? I don't know how the FSI is constructed.
4. Leaking injector - I would assume it would be acting similar as faulty HP pump.
PlasticMac
Member
First, humble apologies for my comments following the filter change, I don’t know how I read the data so badly.
As everyone, but me, has said, fuel pressure is the problem.
Exactly as Andy has said, there is no high pressure at the fuel rail.
This could be that the High Pressure Fuel Pump, (HPFP), has failed completely, or that the Pressure Regulating Valve, N276, has failed mechanically, but not electrically, (no short circuit or open circuit DTC).
I'd expect a failed HPFP to deliver some pressure, rather than none at all.
It is not blocked, as the pressure from the electric pump is getting to the Fuel Rail Pressure Sensor.
It is as if it is not being driven, (maybe it has a shear point in the drive, in case the pump seizes), or the internals have disintegrated, so that it is an open flow path. E10 fuel and melted O rings, possibly? I'm not convinced though.
Removal, and inspection of the HPFP is the only way, that I can think of, to check.
The other possibility is that the Pressure Regulating Valve has failed. Again, in such a way that it is an open flow path. This, like everything, is possible, but, for me, unlikely.
As the HPFP is on the end of the camshaft housing, and so not hard to get at, that would be where I'd start.
Again, apologies for yesterday's bum steer.
Mac.
As everyone, but me, has said, fuel pressure is the problem.
Exactly as Andy has said, there is no high pressure at the fuel rail.
This could be that the High Pressure Fuel Pump, (HPFP), has failed completely, or that the Pressure Regulating Valve, N276, has failed mechanically, but not electrically, (no short circuit or open circuit DTC).
I'd expect a failed HPFP to deliver some pressure, rather than none at all.
It is not blocked, as the pressure from the electric pump is getting to the Fuel Rail Pressure Sensor.
It is as if it is not being driven, (maybe it has a shear point in the drive, in case the pump seizes), or the internals have disintegrated, so that it is an open flow path. E10 fuel and melted O rings, possibly? I'm not convinced though.
Removal, and inspection of the HPFP is the only way, that I can think of, to check.
The other possibility is that the Pressure Regulating Valve has failed. Again, in such a way that it is an open flow path. This, like everything, is possible, but, for me, unlikely.
As the HPFP is on the end of the camshaft housing, and so not hard to get at, that would be where I'd start.
Again, apologies for yesterday's bum steer.
Mac.
PlasticMac
Member
PlasticMac
Member
Andy,
Block 04 is System Pressure Test, which compares Actual Pressure against a Set Point. Don't know the Set Point value, but my guess is the test is done with the Fuel Pressure Regulator closed, (to give Max pressure), and the Set Point will be the max of 150 Bar.
The pre-requisite for Test On, will be a pressure to measure, I'd think. Hence Test Off on Jeremy's car, and OK on yours.
Mac.
A2Steve
A2OC Donor
Which I haven't got in stock :-(
StevieG
Member
I'm Jeremy's VCDS provider. Thank you for the invaluable help and assistance!
The first set of readings taken immediately before and after filter change showed unchanged actual readings (3.8) at any engine speed.
The second set, taken 24 hours after the filter change showed that the actual pressure was closely matching target pressure at any engine speed. So this was different behaviour. There is screen shot of the engine faults that reoccurred after clearing faults.
The first set of readings taken immediately before and after filter change showed unchanged actual readings (3.8) at any engine speed.
The second set, taken 24 hours after the filter change showed that the actual pressure was closely matching target pressure at any engine speed. So this was different behaviour. There is screen shot of the engine faults that reoccurred after clearing faults.
StevieG
Member
This the full scan:
VCDS-Lite Version: Release 1.2
Sunday, 05 November 2023, 19:49:45:7575
Chassis Type: 8Z - Audi A2
Scan: 01,02,03,08,15,16,17,18,37,45,46,56,57,75,76,77
-------------------------------------------------------------------------------
Address 01: Engine Labels: Redir Fail!
Controller: 036 906 013 F
Component: MED7.5.11 G 5130
Coding: 00051
Shop #: WSC 00583
VCID: 125724DC4D77
WAUZZZ8Z123456789 AUZ7Z0B2297864
3 Faults Found:
17428 - Fuel Pressure Regulation: Control Range Exceeded
P1020 - 35-00 - -
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-10 - - - Intermittent
16686 - Cylinder 2: Misfire Detected
P0302 - 35-10 - - - Intermittent
Readiness: 0010 0100
-------------------------------------------------------------------------------
Address 03: ABS Brakes Labels: None
Controller: 8Z0 907 379 D
Component: ESP FRONT MK60 0101
Coding: 0007183
Shop #: WSC 00000
VCID: 49E5C3B060A1
No fault code found.
-------------------------------------------------------------------------------
Address 08: Auto HVAC Labels: None
Controller: 8Z2 820 043
Component: A2-KLIMAVOLLAUTOMAT 0406
VCID: F59DFF40DCD9
4 Faults Found:
01271 - Positioning Motor for Temperature Flap (V68)
41-10 - Blocked or No Voltage - Intermittent
00716 - Air recirculation Flap Positioning Motor (V113)
41-10 - Blocked or No Voltage - Intermittent
00601 - Potentiometer On Positioning Motor for Central Flap (G112)
30-10 - Open or Short to Plus - Intermittent
00600 - Potentiometer On Positioning Motor for Temperature Flap (G92)
30-10 - Open or Short to Plus - Intermittent
-------------------------------------------------------------------------------
Address 15: Airbags Labels: 8Z0-959-655.LBL
Controller: 8Z0 959 655 E
Component: Airbag Front+Seite 5005
Coding: 01102
Shop #: WSC 02152
VCID: 4EEFF0AC99CF
No fault code found.
-------------------------------------------------------------------------------
Address 17: Instruments Labels: 8Z0-920-xxx-17.LBL
Controller: 8Z0 920 950 P
Component: KOMBI+WEGFAHRS. VDO D04
Coding: 04442
Shop #: WSC 22556
VCID: 4BE9F9B86ADD
WAUZZZ8Z74N006923 AUZ7Z0C2434999
2 Faults Found:
01176 - Key
65-10 - Unauthorized - Intermittent
01177 - Engine Control Unit
49-00 - No Communications
-------------------------------------------------------------------------------
Address 45: Inter. Monitor Labels: None
Controller: 8Z0 951 171
Component: Innenraumueberw. D04
Coding: 00001
Shop #: WSC 00000
VCID: FA87EC7CF5C7
1 Fault Found:
01463 - Alarm triggered by Sensor for anti-theft alarm System
43-00 - Closed
-------------------------------------------------------------------------------
Address 46: Central Conv. Labels: None
Controller: 8Z0 959 433 AF
Component: Komfortgerát TBD 1210
Coding: 06859
Shop #: WSC 02138
VCID: 8A67BCBCA527
7 Faults Found:
01336 - Data Bus for Comfort System
80-10 - Single-Wire Operation - Intermittent
01370 - Alarm triggered by Interior Monitoring
35-00 - -
01369 - Alarm triggered by Hood Switch
35-00 - -
01374 - Alarm triggered by Terminal 15
35-00 - -
01371 - Alarm triggered by Door Contact Switch; Driver's Side
35-00 - -
01561 - Left Rear Door
61-00 - Won't De-Safe
01560 - Passenger Door
61-10 - Won't De-Safe - Intermittent
-------------------------------------------------------------------------------
Address 56: Radio Labels: 8E0-035-1xx-56.LBL
Controller: 8Z0 035 186 G
Component: concert II GRO 0001
Coding: 00001
Shop #: WSC 02138
VCID: 40F3DE94539B
No fault code found.
End --------------------------------------------------------------------------------------------------
Good Afternoon,
I have decided to ignore the data Jeremy posted on Saturday evening and my comparison with it yesterday, it is all just too absurd, best to avoid GIGO, leave it on the back burner for now.
I have more to say (sorry!) but no time now or for a couple of days, in a few days, but I will keep an eye on how the thread develops.
Andy
I have decided to ignore the data Jeremy posted on Saturday evening and my comparison with it yesterday, it is all just too absurd, best to avoid GIGO, leave it on the back burner for now.
I have more to say (sorry!) but no time now or for a couple of days, in a few days, but I will keep an eye on how the thread develops.
Andy
Good Afternoon Mac,
I have no idea where you found the first picture and it is using the new Ross-Tech lbl file!!!!
Your point is still very valid though.
Andy
PlasticMac
Member
I think it's one of yours, from the Media tab.
Mac.
PlasticMac
Member
Firstly, thank you for your help too!
There’s just one odd reading, where, the spec pressure is higher than the actual, 69 Bar v 45 Bar.
The "Fuel Pressure Range Regulation Range Exceeded DTC does point to fuel pressure being a problem.
The HPFP is still my prime suspect.
Jeremy mentioned that the EML came on after the DTCs were cleared, was this after the scan results you posted?
If so, there could be a fault code that only triggered into the drive, but wasn't present at the time of the scan.
So a further scan, just of the Engine controller would be great.
The FSI lbl file should be available to you as an official update from Ross-Tech.
For users of VCDS Lite, it is not available from Ross-Tech, as Lite is no longer supported, no updates since 2012. So a download from this forum is the only option for Lite users like me.
Mac.
JavaGreen
Member
as previously stated…. if not electric fault it would have likely been 1 to 4 as stated. A 2nd HPFP from ASteve would have been useful, if that is not the cause…. they are very easy to sell on with this forum so money would not have been wastedI had this problem….
Firstly…. you said you used low grade fuel - remove the fuel and put the correct grade in
I had this problem- turned out to be fuel filter, had not been changed for 8 years (I had, had car for less than 12 months) so had it serviced with new filters and new plugs etc - no change
The filter had disintegrated consequently, all filter debris had gone everywhere so had all fuel lines cleaned out - no change
Next step was to have HPFP removed and stripped - this was the problem, rubber rings inside had started to disintegrate and causing blockage ….. had replacement from A2Steve and once fitted car was back to normal
Also, get your name down for one of A2Steve’s cpu exchanges
Money well spent if you have the fsi.Done!
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