Member Since: 07 Jun 2020
Location: Sussex
Posts: 6
Bad Fuel pump
Click image to enlarge
Click image to enlarge
My D3 08 was going into Limp mode fairly regularly (dash lights, lowered suspension, the full works) and it was coming up with a low fuel pressure fault code. Changed the LPFP to no avail, its had a new filter within the last few months, so changed the HPFP for a second hand VDO to see if that knocked the issue on the head. However, after bleeding, the car started and ran for about 45 seconds before cutting out, bled it again and tightened all connections and it fired up but ran rather lumpy as seen in first picture. It then stopped again after a while and now will crank and fire but immediately dies. Am I just unlucky enough to have put a second duff pump in or could there be another problem? The pressures recorded look way too low and all over the place but could it be electrical rather than mechanical?
Thanks for any help in advance
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8th Sep 2020 1:32 am
French Collection
Member Since: 15 Apr 2020
Location: Aix-en-Provence
Posts: 46
Having similar problems, though so far have only changed LPFP. This did not solve the original intermittent fault.
Sounds like you might still have an LPFP problem Have you checked pressure at Schrader valve and pump current as per Robbie's guide?
After more investigations on mine today it now won't start. Possibly because I disconnected many of the pipes to pass some air through to make sure there were no blockages.
Dropped tank again and checked voltage to LPFP to find that it is only 4V. Now to find out why?
I may well have a HPFP problem but I am not going to change it until I have bottomed out LPFP issues.
27th Sep 2020 5:57 pm
ds23man
Member Since: 19 Jan 2013
Location: Ainum
Posts: 227
Did you replace the complete LPFP unit with all the hardware or just replaced electrical pump?
27th Sep 2020 6:14 pm
supersiecosse
Member Since: 24 Aug 2020
Location: Dumfriesshire
Posts: 60
Re: Bad Fuel pump
BPattenden wrote:
Changed the LPFP to no avail, its had a new filter within the last few months, ...............
This may not help but may also be worth a look.
Having recently changed the Diesel Filter on my 2014 D4 I had issues with locating the filter into the housing properly. As we know it is a twist to lock/locate set-up. One of the three locating tangs would not locate properly into the housing and was continually twisting out of the housing and could be seen below the groove in the housing where it is supposed to be held. [Hoping this makes sense].
Figuring this would allow air in and fuel out and all associated problems that come with it.... I persevered until it located as required. Many attempts were made to get this right and a thorough check for fuel leakage was made.....of which there was none; thankfully.
It strikes me as being cheap and nasty that the mounting for the Fuel Filter is made of "Plastic" and is/will be prone to wear/damage.
Upon refitting the heat shield [tin plate] back in front of the Filter I happened to notice there is a Electrical connector Block and 3 wires running behind the far right bolt that holds this tin plate in place.
In my case these wires were sitting on top of the bolt threads after fitting (cause of possible chaffing short circuit in future).......I only noticed this issue as I was looking for diesel leakage. I could not determine what these 3 wires were for or where they went....(lying on my back with a torch straining my neck).
It might be something of nothing.....but may be worth a quick inspection. Given that the Fuel Filter had recently been replaced in your case.
27th Sep 2020 6:35 pm
French Collection
Member Since: 15 Apr 2020
Location: Aix-en-Provence
Posts: 46
ds23man wrote:
Did you replace the complete LPFP unit with all the hardware or just replaced electrical pump?
I replaced the complete module
27th Sep 2020 7:22 pm
French Collection
Member Since: 15 Apr 2020
Location: Aix-en-Provence
Posts: 46
Re: Bad Fuel pump
supersiecosse wrote:
BPattenden wrote:
Changed the LPFP to no avail, its had a new filter within the last few months, ...............
This may not help but may also be worth a look.
Having recently changed the Diesel Filter on my 2014 D4 I had issues with locating the filter into the housing properly. As we know it is a twist to lock/locate set-up. One of the three locating tangs would not locate properly into the housing and was continually twisting out of the housing and could be seen below the groove in the housing where it is supposed to be held. [Hoping this makes sense].
Figuring this would allow air in and fuel out and all associated problems that come with it.... I persevered until it located as required. Many attempts were made to get this right and a thorough check for fuel leakage was made.....of which there was none; thankfully.
It strikes me as being cheap and nasty that the mounting for the Fuel Filter is made of "Plastic" and is/will be prone to wear/damage.
Upon refitting the heat shield [tin plate] back in front of the Filter I happened to notice there is a Electrical connector Block and 3 wires running behind the far right bolt that holds this tin plate in place.
In my case these wires were sitting on top of the bolt threads after fitting (cause of possible chaffing short circuit in future).......I only noticed this issue as I was looking for diesel leakage. I could not determine what these 3 wires were for or where they went....(lying on my back with a torch straining my neck).
It might be something of nothing.....but may be worth a quick inspection. Given that the Fuel Filter had recently been replaced in your case.
I think those wires are for a water detection sensor in the filter housing
27th Sep 2020 7:24 pm
BPattenden
Member Since: 07 Jun 2020
Location: Sussex
Posts: 6
Click image to enlarge
Click image to enlarge
So mine was most definitly the HPFP as my third pump, a brand new VDO unit has gone in and after running the volume pump for about a minute to bleed/fill everything up I turned the key on and she fired up immediately. I've been driving it about for the last few days and no issues at all. For comparison I've included some screenshots of the idle pressure of both pumps over about 45 seconds. Annoyingly the colours switch around but you can clearly see the massive difference in pressure fluctuations between the 2 pumps. I really recommend getting an IID tool, helps a load!
28th Sep 2020 1:38 pm
BPattenden
Member Since: 07 Jun 2020
Location: Sussex
Posts: 6
French Collection wrote:
After more investigations on mine today it now won't start. Possibly because I disconnected many of the pipes to pass some air through to make sure there were no blockages.
Dropped tank again and checked voltage to LPFP to find that it is only 4V. Now to find out why?
I may well have a HPFP problem but I am not going to change it until I have bottomed out LPFP issues.
On the first point, make sure you have run plenty of diesel through, I recommend taking the fuel pump relay out and sticking a bit of wire in, leave it to run for at least a minute while you bleed at the Schrader/check visible joints for leaks. Then replace the relay and try ignition. Make sure you have plenty of diesel in the tank too, I can't remember where it was posted but a member had problems bleeding with only a quarter tank of fuel.
On the second point do you mean 4 Amps? I read through Robbies guide but later on in the post its pointed out that his is a D4 which seem to draw more current than the D3 which will normally draw between 4 and 5 Amps on a normal English summer day. If you are getting only 4 volt then I think that's probably a battery issue?
28th Sep 2020 2:05 pm
French Collection
Member Since: 15 Apr 2020
Location: Aix-en-Provence
Posts: 46
It was 4V, but this was the voltage for the fuel gauge sender.
I appeared to have 0 on the pump supply either because of the timeout (15 - 20 secs) on the pump) when engine is not running or because I had the tank at an angle when I was testing and one of the senders thought it was empty and cut the pump supply.
So mostly stupidity on my part.
In the meantime, I confirmed a PCV fault with live values on the IID tool and have since changed the HPFP. Fingers crossed now!Bentley 8
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16th Nov 2020 9:43 am
discovery3ski
Member Since: 25 Dec 2012
Location: leicester
Posts: 734
When mine did the limp mode and F on the gears stunt we went through the same process and even found a hole in the fuel tank from rodents. Did tank, low pressure pump then distribution to injectors before a new expensive high pressure pump fixed it. Plus side is it runs like a sewing machine now almost three grand later.....Discovery 3 tdv6 HSE 2007
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16th Nov 2020 12:22 pm
Lrsg
Member Since: 10 May 2020
Location: Norway
Posts: 77
What fault codes do you get?
16th Nov 2020 8:29 pm
French Collection
Member Since: 15 Apr 2020
Location: Aix-en-Provence
Posts: 46
I was getting P00087, sometimes P00088 and 00092 I think also.
I changed the HPFP at the weekend, all good so far but only done 2 55km trips so too soon to conclude that I'm home and dry!Bentley 8
Rolls Royce Silver Shadow
Triumph Stag
Volkswagen Karmann Ghia Razor Edge
Jaguar XJC
Jaguar E-type
Jaguar XK8
Land Rover Discovery 4
Mercedes E350
Ford Granada 2.8 Ghia X
Ford Granada 2.8i Ghia X
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