Member Since: 02 Sep 2012
Location: Old Windsor
Posts: 403
Fuel pressure control valve. FPCV - Replaceable? orFP sensor
Is it possible to replace either the Fuel pressure control valve or the FP sensor (the one or more that are AFTER the HP fuel pump) .
In the ongoing saga of my randomly limping D3 the list of things to check includes the FPCV. I cant seem to find much info about this device. Is it part of the HP fuel pump? Can it be changed independently of the HP fuel pump?
The fault we are seeing is that once warmed up, the car will drop into limp mode, HDC off, limited gears etc.
The fault logged is Pressure too low. (There are no injector faults etc). A local 4x4 indy is telling us we need an HP fuel pump next (they've spent £1000 of our money changing the LP pump and the filter )
However, given the intermittent nature (only once warmed up and then still intermittent: I managed a 20+ mile/60 min journey to London without incident, but had to stop 8 times coming home) and the input of another local mechanic - If the HP pump was shot, it wouldn't start, let-a-lone run. It wouldn't have the pressure to kick down etc (which it does, well, in fact, it tends to go to limp mode while at 1.5K-2K revs, often when pottering/cruising 30-50mph when there's a gear change (up or down), almost never when accelerating)... I suspect its a sensor fault or wiring issue...
So, can the sensor/regulator be replaced without the cost of the HP pump? which sensor throws the Pressure too low fault?
mjcp03/2007 D3 HSE
98 Audi A4 Avant 2.5 TDi Quattro
Gone but not forgotten
03/2003 330Ci Convertible
93 Corrado 2.0l 16V
98 M3 Evo Cab
28th Sep 2015 7:46 am
Woodland D3
Member Since: 29 Oct 2015
Location: Derbyshire
Posts: 2
Hi what was the outcome to this fault in the end ?
29th Nov 2015 11:23 pm
mjcp
Member Since: 02 Sep 2012
Location: Old Windsor
Posts: 403
£1200 out of pocket and a still failing D3....
Then one morning it wouldn't start - Battery was flat.
New battery and it started, had 1 x reoccurrence of the fault and was fine for the next 3-4 weeks.
In that time noticed a strange engine revs related noise and then a battery light came on. New alternator needed...
So in conclusion, I suspect the alternator or battery had packed in and it was an electrical issue that caused it all: Fluctuating current/Voltage caused the sensor to mis-read => ECU went into limp mode.
We, the local greasy spanner garage and various others I discussed with all said "Its electrical, not mechanical" and passed this on to the Indy, Nick Kerner 4x4, Berkshire, but they either ignored or had better reasons to not test the battery and spend £1200 of our money on a LP fuel pump, Filter, steering sensor alignment, levels sensor recalibrate etc.... They were telling us that it needed an HP fuel pump next and then maybe injectors too... So we would have been another £1700 out of pocket (Their job times are NOT book times) and still had a failing car!
mjcp03/2007 D3 HSE
98 Audi A4 Avant 2.5 TDi Quattro
Gone but not forgotten
03/2003 330Ci Convertible
93 Corrado 2.0l 16V
98 M3 Evo Cab
3rd Dec 2015 7:43 am
Lee j
Member Since: 08 Dec 2019
Location: Lechlade
Posts: 6
Did the new alternator cure your issues as I'm having exactly the same problems. The garage I've taken it to believes it to be hpfp.
8th Dec 2019 5:50 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5042
Do you have any diagnostic codes from the garage, or have you an IID tool?
From experience the alternator can cause voltage spikes in the 5v signals to the PCV, VCV, and the FRPS.
If this happens it can be a nightmare to detect unless you are using dedicated LR diagnostics such as GAP IID. However, you can test the signal values to the above sensors and if you are seeing a reference above 5V then I would suspect alternator failure.yµ (idµ - eAµ) ψ=mψ
8th Dec 2019 6:11 pm
Lee j
Member Since: 08 Dec 2019
Location: Lechlade
Posts: 6
I don't know the exact code but he showed me on his bit of kit which he says is the latest two figures which were 12% and 20% at idle I think. under load they should have increased but they didnt which he says its pointing towards hpfp being faulty. I also had to change my battery recently but no battery light yet.
8th Dec 2019 6:26 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5042
At idle the vol cntrl valve should be around 21% and the pres cntrl valve around 13,5% so you're not too far away there. Both values as you say should begin to climb as the rpm increases. If it does not it should not be taken for granted the HPFP is fubared!! It is not that common for these HPFP sensors to fail, and I would consider it unusual for both to pack up at the same time. There are many simple things which can cause your issue and should be thoroughly checked first such as the fuel filter and LPFP
My suggestion to you is to get your own IID bt tool, and with help from here you can get to the bottom of this yourself. If, you are so inclined and familiar with working on your own vehicles.
You are going to need it again at some point and it will pay for itself usually in a short space of time. As far as diagnostics for these vehicles are concerned, the "latest" simply doesn't mean diddly squat unless the tool being used is a dedicated LR diagnostics!! You may also be led down a blind alley by non dedicated LR diagnostics, as well as a very much lighter wallet and still stuck with the same problem!!!
If you can obtain the codes so far and post them here further help might be possible, but ultimately you would be better off investing in the tool yourself especially if you are keeping it.
The copied live values below shows what things should look like at idle for a 2.7 TDV6
Voltage ign key on 13.84v
Voltage from DC converter 48.62v
Volume control valve 21.87%
Throttle pedal angle 0%
Pedal sensor 1 voltage 0.75v
Pedal sensor 2 voltage 0.25v
Pressure cntrl valve 13.67%
Mass air flow sensor signal A 4 g/s
Intake air temp 24deg C
Internal ECU temp 35 degC
Input/output status fuel lift pump. ACTIVE
Input/output status fuel lift pump power monitor. ACTIVE
Boost pressure actuator Bank 1. 0.87%
Boost pressure adjustment 87%
Fuel rail temp before FMEM 60degC
Generator command 46.87%
Generator feedback 23.84%
Generator voltage set point 15.70v
Fuel pressure 23.09 MPa
Engine speed 516 rpm
Eng oil temp 77degC
Coolant temp 78degC
Cylinder balance offset:
Injector 1. 103k. Inj 2. 0.99k. Inj 3. 0.84k. Inj 4. 0.93k. Inj 5. 0.98k. Inj 6. 1.19k
Ambient temp 12 degC
Battery voltage 13.97v
Boost air temp 22.30degCyµ (idµ - eAµ) ψ=mψ
8th Dec 2019 7:26 pm
Lee j
Member Since: 08 Dec 2019
Location: Lechlade
Posts: 6
thank you for your help. The guy said he suspected the hpfp and has sent the info to landrover for confirmation or not as the case may be. All he deals with is landrover so I would assume its the correct kit. He also said it was very rare for these to fail so hopefully its something simpler/cheaper lol. I'll find out the codes and post on here tomorrow.
8th Dec 2019 7:59 pm
Lee j
Member Since: 08 Dec 2019
Location: Lechlade
Posts: 6
Just off the phone to the garage and it's the p0087 code. He says there's a whole host of things I need to check. Fuel filter various sensors lpfp readings hpfp sensors fuel lines etc then move onto the air intake system and wiring so looks like I'm going to be busy lol
9th Dec 2019 4:19 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5042
I thought the garage had seen codes referring to the VCV or FPCV? In any case fit a genuine LR fuel filter or a good OEM such as Mahle, Knecht, etc. If you're going to do the work yourself you might want to begin here!
Member Since: 04 Jun 2012
Location: Edinburgh
Posts: 15
Have you had the tank out mate?
10th Dec 2019 3:32 pm
wedgev8
Member Since: 17 May 2019
Location: Kerpen
Posts: 181
Lee, without a diagnostic tool like e.g. an IId Tool it will be very difficult to find the real fault.
Checking the supply voltage of the FRPS and and also of the PCV and VCV while driving with warm engine is important.
Also the live value Graph of the fuel pressure is interesting.
Regards, Tom
Last edited by wedgev8 on 12th Dec 2019 8:36 pm. Edited 1 time in total
12th Dec 2019 8:23 pm
wedgev8
Member Since: 17 May 2019
Location: Kerpen
Posts: 181
PROFSR G wrote:
Do you have any diagnostic codes from the garage, or have you an IID tool?
From experience the alternator can cause voltage spikes in the 5v signals to the PCV, VCV, and the FRPS.
If this happens it can be a nightmare to detect unless you are using dedicated LR diagnostics such as GAP IID. However, you can test the signal values to the above sensors and if you are seeing a reference above 5V then I would suspect alternator failure.
o
...the PCV and VCV are not connected to the 5V reference voltage. These are directly supplied by the battery/generator voltage with the positive side. You can see this in the wiring diagram.
12th Dec 2019 8:34 pm
Rolyboy
Member Since: 01 Nov 2020
Location: Wrexham
Posts: 14
Cranks won’t start
Hi I was wondering if any one could help pretty please.
I have a 2.7 tdv6 2007 it cranks but won’t start . When I first got it it did tick over briefly x3 only for a few seconds each time . Since then after research I have changed .
Low pressure pump in tank
Injectors
Fuel filter
EGR BLANK
New battery
SINCE THEN I have not got it to start at all .
I have fuel through Scharder valve
Fuel at injectors
I can hear fuel pump workin in the tank however sounds like there is a waterfall in there
Fuel pressure reading is 2700 on diagnostic on cranking
Engine rpm is 150 to 170 on cranking
PCv 40 %
I’ve emptied and cleaned the tank
Any advice would be deeply appreciated.
I’m a key worker and need to get it up and running as I’m using my sister car at present
1st Nov 2020 10:23 am
darrind
Member Since: 04 Jul 2008
Location: In A World of My Own!
Posts: 2889
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