Member Since: 17 May 2019
Location: Kerpen
Posts: 181
LPFP replaced
After reading Robbie's guide I have checked my pump in the hope to solve my limp mode problems.
Pressure was about 0.3 bar with ignition on and about 0.2 bar when engine ideling. At Higher revs it goes negative. I measured the current with about 2 amps. This all seems very low, so I measured the resistance of the LPFP. It was only 0.2 ohms!!! (Nearly short to earth, but it was a little working)
I bought a new pump (magneti marelli) and built it into the tank.
The new pump shows 3.7 ohms (much better) and I measured current with about 5.8 amps after fitting it.
With my pressure gauge connected now I see 0.4 bar with ignition on and a dancing needle at idle and 0.1 bar steady at higher revs.
Very serious! You can see it in fotos and video.
The only thing I have reached ist limp mode is comming less often.
Last edited by wedgev8 on 20th Nov 2019 6:59 am. Edited 2 times in total
17th Nov 2019 9:50 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5036
Some points you might consider which may be of assistance to you.
At idle you should be seeing a pressure of 0.4 bar (steady). A current draw of 5.8 amps is in my opinion a bit too low as you should be seeing closer to 9.0 amps especially in this colder weather. Did you change the fuel filter, and if so what brand of filter are you using?
If the filter is new and of "good quality" ie(original LR, Mahle, Knecht, MAN, et al) then you may need to look at the elec conns again! (but I have seen many cases of fuel pump issues caused by cheap fuel filters)
You could also try a flow test at the schrader valve where you should see 2.0 ltrs p/min for a weak but operational pump, and about 3 ltrs p/min for a strong unimpeded flow! The other possible failure of current flow might be the fuel pump relay!yµ (idµ - eAµ) ψ=mψ
18th Nov 2019 1:36 am
aja4x4
Member Since: 14 Apr 2019
Location: Westbury
Posts: 2463
The other thing to check us the wiring plug behind the wheel arch linner on the passenger side. Its common for the connectors to get damp and go green.
18th Nov 2019 6:11 am
jetmech
Member Since: 22 Feb 2016
Location: Suffolk
Posts: 271
Sounds like a hpfp issue to me. It’s just returning the fuel to the tank, when the engines running.Simon.
2008MY Dicovery 3 TDV6 SE Manual
18th Nov 2019 9:47 am
wedgev8
Member Since: 17 May 2019
Location: Kerpen
Posts: 181
I will check with a new pressure gauge again next week because my old one is leaky now. I tried to measure again with a longer rubber hose and found the needle no more dancing but splashing fuel in engine bay and on me.
Filter ist a new one from MANN Filters Germany. Maybe there is a difference in pressure because I have the screw in type of Filter in my car.
In the wheel arch my car has no connectors. MY 2008. The earth connection also looks good. Very clean and tidy under the arch cover.
Will try to measure at the tank connector while engine is running. Although I have no idea how this could be managed.
I think I could poke into the cable with a needle connected to my DMM. The cable near the tank.
18th Nov 2019 9:50 pm
discovery3ski
Member Since: 25 Dec 2012
Location: leicester
Posts: 735
Where under the arch is the fuel pump connector please?Discovery 3 tdv6 HSE 2007
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19th Nov 2019 9:15 am
wedgev8
Member Since: 17 May 2019
Location: Kerpen
Posts: 181
Right hand in driving direction front under the wheel arch cover you will find a connector on early models. But the fuel pump connector is above the tank. Not reachable without lowering the tank.
19th Nov 2019 12:01 pm
DiscoJeffster
Member Since: 27 Feb 2016
Location: Perth
Posts: 204
Is the replacement pump identical to the original? If not then all the talk of expected current and pump flow has no bearing on this. Those values will align to the new pump’s capability.
19th Nov 2019 1:48 pm
KostasA
Member Since: 23 Aug 2015
Location: nairobi
Posts: 286
from mine experience when i did the LPFP, after a while i had to do the HPFP. my logic says that a failing LPFP is damaging the HPFP as well. although you get limp mode to protect HPFP this second on low fuel flow might damage the HP pump.
now you need to see the codes of the limp mode. only then you will be 100% sure.
19th Nov 2019 4:26 pm
wedgev8
Member Since: 17 May 2019
Location: Kerpen
Posts: 181
P064200 Code ist causing the limb mode. Normally Code P0194 would give the limb mode first, but since I have an external 5V supply for the fuelrail pressure sensor this circuit is working fine. When starting from cold I can drive about 5miles without problems. When engine gets hot I can see voltage dips in the internal 5V reference voltage in the Graph in IID Tool everytime when giving load to the engine. Small hills or bridges e.g.. Then I have to use the cruise control otherwise the Car is jerking and shocking because the voltage dips act on the accelerator Pedal, which is also connected to the 5V circuit.
19th Nov 2019 5:04 pm
DiscoJeffster
Member Since: 27 Feb 2016
Location: Perth
Posts: 204
I don’t know how many of these threads I’ve read for D3 between all the forums. 99% have turned out resolved once the HPFP is replaced. Good luck. Let us know how you go.
20th Nov 2019 6:49 am
wedgev8
Member Since: 17 May 2019
Location: Kerpen
Posts: 181
...I would not hesitate to change the pump if I had a warranty this would solve the Problem and have my peace.
But I'm afraid about the horrible work and costs and then the problem goes on because I cannot find a context between HPFP and the Limb Mode causing voltage dips.
On top I have the challenge to Check all electric circuits without a correct wiring diagram for my car.
I have the diagram for EUR 3 to VIN 493487 and EUR 4 to VIN 493487. My disco is a EUR 4 with works particulate filter and has VIN 8A464491.
Some cabels and connectors are like the EUR3 diagram and some others Like EUR4.
This makes it Not very easy.
20th Nov 2019 7:18 am
jenseneverest
Member Since: 12 Jun 2017
Location: somewhere
Posts: 769
wedgev8 wrote:
P064200 Code ist causing the limb mode. Normally Code P0194 would give the limb mode first, but since I have an external 5V supply for the fuelrail pressure sensor this circuit is working fine. When starting from cold I can drive about 5miles without problems. When engine gets hot I can see voltage dips in the internal 5V reference voltage in the Graph in IID Tool everytime when giving load to the engine. Small hills or bridges e.g.. Then I have to use the cruise control otherwise the Car is jerking and shocking because the voltage dips act on the accelerator Pedal, which is also connected to the 5V circuit.
Interesting.
Are you then saying that the cruise control is on a separate system to the 5v throttle circuit ?
You do not get issues using the cruise control ? or is the issue is only less frequent?
on my d3 (manual gearbox) i am getting jerking at between 1800 and 2200rpm. The problem is worse when the d3 is cold. Using cruise control will reduce or mask the issue but, it is still there. I have no fault codes and i am happy with my injector balance figures.
My plan is to check glow plugs, then LPFP.... car is 14 years old with 150000 miles so it has not done bad on all original parts.
20th Nov 2019 12:57 pm
wedgev8
Member Since: 17 May 2019
Location: Kerpen
Posts: 181
In modern cars the accelerator pedal has two potentiometers working on two separate sensor circuits. (5V A and 5V B)
This is for security reasons. The Disco also, as you can see in the electric diagram. When my car warms up there are the voltage dips after about 3 to 5 miles in the A 5V circuit. These dips down to nearly 0v are causing a jerking or rattling acceleration because the A circuit s not in a proper corelation to the B circuit in Pedals potentiometers.
When this jerking comes up I start the cruise Control and can drive smoothly . Although I can see further voltage dips in the graph in IID Tool. This is possible because the Pedal is separate from the cruise control.
20th Nov 2019 2:25 pm
Breg90
Member Since: 04 Feb 2017
Location: Falkirk
Posts: 360
The wiring diagram - subscribe to land rovers topix for a day and down load the wiring info for your car. If you are patient enough you can download the entire manual. However LR have it in ~ 10 page individual PDF’s so it is a fair commitment to download the full thing. But the whole wiring data should only be a few hours work
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(Nearly short to earth, but it was a little working)
