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Please help! Fuel rail pressure on a D3 (2007) EU4
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KostasA
 


Member Since: 23 Aug 2015
Location: nairobi
Posts: 286

Greece 

So again new day new measurements 8)

we start with pressure test:

engine switched off



ignition ON, pressure 6.8 PSI



engine ON, pressure 5 PSI




then we do the electrical test:

test on battery, ignition is OFF 12.44V




test on Test on Fuse engine is running: 14.22V


so now back to school following Ohms law for a 25A fuse resistance is: 2.36 Ohms

So theoretical current is 6 Amps.

According to previous posts values should be 6.7PSI and close to 9Amps current

Taking the test one step further graph of REVS vs fuel pressure(MPa) as it comes on live data



Then REV vs Oil Temp, Fuel temp and Manifold pressure (kPA)




fault code was on the last section of those graphs

now please someone can guide me on the fault, LPFP? HPFP? none of the two?
  
Post #17587696th Jan 2017 7:08 am
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Junds
 


Member Since: 22 Dec 2016
Location: Zug
Posts: 16

Switzerland 2007 Discovery 3 TDV6 HSE Auto Orkney GreyDiscovery 3

the pressure is 0.37bar, which is below the expected value of 0.5bar.

Your current measurement might be wrong. I can't see on the picture how you set the meter. It must be on A-DC (10A range). Then when you switch on the ignition the pump only runs for a short time to build up some initial pressure I guess. When you start the engine and let it in idle it runs all the time. So maybe you were just too late to measure, that happened to me with the scope. Check again.

Your reading I would interpret as 0.07A, that's not possible, because then there would be no pressure at all.

As far as I could find information, the problem with the LP is that when driving the pressure will fall until -0.3 bar. I would guess that with a weak pump it should be ok as long as you don't accelerate too much. If you drive with the IID on, then you can drive carefully watching for the 'fuel pressure'. I would expect that then the error is not appearing. Or on the other side, can you provoke the error by accelerating max?

We just went on a hill offroad and had pressures up to 1100bar. My LP pump is old and the current is too low (3.8A instead of the 5A from Robbie). Unfortunately I can't measure the pressure as I lack such a nice gauge... but we didn't get any error. (as Robbie said- there are pumps out there with worse current values...)
In some days I will get a pressure sensor from the US and do the measurement, but I expect it to be lower than the 0.5 bar as well.

If you can borrow a scope, then you will see if it is the connections. If the current goes up to 5A, then the connection is fine. If there is a high ripple (see Robbies old pump current) then you see that the current goes up and down with the motor commutation which means the brushes are worn.

Still, the question is how much ripple is acceptable... how low may the pressure be until this error pops up.. Noone seems to know that. Fact is that some day the pump will die completely and you need to exchange it anyway, but then you might get stuck in an unpleasant place.
  
Post #17587756th Jan 2017 7:20 am
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Junds
 


Member Since: 22 Dec 2016
Location: Zug
Posts: 16

Switzerland 2007 Discovery 3 TDV6 HSE Auto Orkney GreyDiscovery 3

your fuel pressure looks ok, its over 20000kPa (200bar). But the question is if there will be enough fuel when accellerating and the pressure goes > 1000bar.

Try that and see if the error pops up.

I cant follow your current calculation. A fuse of 25A should burn when the current gets higher than 25A, but is not very precise. To measure the current you need a shunt resistor of e.g. 0.01 ohm, then measure the voltage over the resistor. Or put the amp meter in line in stead of the fuse and choose Amp-DC, 10A range. Make sure the pump is running.
  
Post #17587776th Jan 2017 7:30 am
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KostasA
 


Member Since: 23 Aug 2015
Location: nairobi
Posts: 286

Greece 

Hi Junds,
thanks a lot for your post. to answer your questions:

Your current measurement might be wrong. I can't see on the picture how you set the meter. It must be on A-DC (10A range). Then when you switch on the ignition the pump only runs for a short time to build up some initial pressure I guess. When you start the engine and let it in idle it runs all the time. So maybe you were just too late to measure, that happened to me with the scope. Check again.

will try again but set up was 10A on A-DC, maybe my meter is not a good one will try to find alternatives. test i did is measure the voltage drop when engine is running and knowing the theoretical resistance of the fuse calculate the current.

If you drive with the IID on, then you can drive carefully watching for the 'fuel pressure'. I would expect that then the error is not appearing. Or on the other side, can you provoke the error by accelerating max?

i did drive with the IID on and had my wife monitoring Rolling Eyes on the graph presented the error was some sort of provoked at the end. for it to happen it needs engine to be warm enough (temperature stays at the middle for some time) and then just happens, no hard acceleration. or if i drive constant speed on high way, around 1800 RPM.

Fact is that some day the pump will die completely and you need to exchange it anyway, but then you might get stuck in an unpleasant place.

that is the main thing i am concerned and would like to replace, question is which of the two. unfortunately were i leave bringing things in is not easy and does take time (around 1 month) if you are to avoid high taxes and not pay 3 times the value!!!!

your fuel pressure looks ok, its over 20000kPa (200bar). But the question is if there will be enough fuel when accellerating and the pressure goes > 1000bar.

I am not sure that i follow here. according to the IDD fuel pressure is in Mpa so the 20,000MPa reading should be 2000bar ( 1Mpa = 10 bar). what i am getting wrong here?
  
Post #17587826th Jan 2017 7:47 am
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KostasA
 


Member Since: 23 Aug 2015
Location: nairobi
Posts: 286

Greece 

After actual measurements of Amps





3.9 A, after a small run engine is on. So based on Robbie's post pump is at the edge of collapsing given of course the pressure measurement.

Let's hope that by changing will solve the problem Rolling Eyes
  
Post #17588586th Jan 2017 10:52 am
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KostasA
 


Member Since: 23 Aug 2015
Location: nairobi
Posts: 286

Greece 

After all this time took the bullet and changed the reservoir pump (thanks for the wonderful post and guidance!). took her for a ride and after 40 min of driving and heat building up here we go again:

P-0087 fuel rail/system pressure - too low - actuator stuck open...


please any advise.........

did also pressure test, same as before. cranking the engine almost 7PSI, starting it 5 PSI. tomorrow will measure the current as well but i really don't understand. changed the whole pump module and in terms of pressure am at point 0.
  
Post #176934926th Jan 2017 3:10 pm
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KostasA
 


Member Since: 23 Aug 2015
Location: nairobi
Posts: 286

Greece 

current test 4.2 Amps......


any suggestions please...
  
Post #176993927th Jan 2017 3:01 pm
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dd disco
 


Member Since: 08 Oct 2010
Location: S.E. Suburbs, Melbourne, Victoria
Posts: 9

Australia 2008 Discovery 3 TDV6 HSE Auto Stornoway GreyDiscovery 3

Hi KostasA, your pump pressures look to be better than mine. Mine sits down at 3.5psi when the engine is running, and the needle is unsteady. I replaced the fuel filter which has made no difference.

However the fault you are having is exactly the same as mine, approx 40 mins driving on the highway then "bing" and Christmas lights with multiple errors. When I read the codes P0087 is the only one that is not communication related. I have been turning the engine off and restarting then resetting the fault codes whilst still moving, this allows me to continue driving sometimes for a few hundred meters, and sometimes for another 50 kms or more.

Daniel.
  
Post #177081129th Jan 2017 8:07 am
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KostasA
 


Member Since: 23 Aug 2015
Location: nairobi
Posts: 286

Greece 

Hi Daniel, replied on the other post as well. I did changed the LPFP as well, straight forward as a process but did not solve the problem. After having checked all fuel lines and most of the cabling my next step will be the fuel pressure switch, on the common rail LH side. According to a mechanic ( in Greece) it can produce that fault plus it controls the LPFP as well. This is a cheap on from eBay around 50E but it will take some time to arrive. Unfortunately can not source it locally. Once I'll replace it will late you know. I don't think that HPFP is faulty as my live readings show a very good range plus will take Robbie's propasalbthat is very rare to go bad.

In your shoes would go first for the sensor and then for the pump. Always start from the simplest to the most difficult.

Cheers,
Kostas.
  
Post #177081829th Jan 2017 8:17 am
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dd disco
 


Member Since: 08 Oct 2010
Location: S.E. Suburbs, Melbourne, Victoria
Posts: 9

Australia 2008 Discovery 3 TDV6 HSE Auto Stornoway GreyDiscovery 3

Hi Kostas,

Sounds like a good plan, however I was told by a mechanic friend that his first suggestion would be HPFP as he replaces a lot more of these than low pressure ones and sensors. I am hoping that it will be one of the cheaper options.

I will attempt to get some parts locally if not too expensive in the next day or two to see what I can find out.

Daniel.
  
Post #177083329th Jan 2017 9:02 am
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KostasA
 


Member Since: 23 Aug 2015
Location: nairobi
Posts: 286

Greece 

HPFP, as a spare part is the most expensive. you will not get away with anything less than 700E plus installation (which is a big job cause when you are there you will change the belt also). so the spare parts alone will go around 1,000E.
LPFP is around 300 to 400 E and job is easier. what needs to be addressed in your case is the flickering of the pressure while you accelerate, remember you measure before the HPFP and value is solo for the low pressure side.
  
Post #177084129th Jan 2017 9:24 am
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dd disco
 


Member Since: 08 Oct 2010
Location: S.E. Suburbs, Melbourne, Victoria
Posts: 9

Australia 2008 Discovery 3 TDV6 HSE Auto Stornoway GreyDiscovery 3

I was concerned about the flickering also, I haven't yet showed the images, or video to my friend so I will see what he has to say tomorrow.

I am hoping to replace which ever parts are required myself, I will try to get hold of a pressure switch and possibly a low pressure pump tomorrow depending on local price. Usually it is cheaper to buy from the UK even though that means waiting for shipping.
  
Post #177085529th Jan 2017 9:59 am
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AndyGreen
 


Member Since: 18 Jul 2007
Location: Tramore
Posts: 97

Ireland 2006 Discovery 3 TDV6 S Auto Zambezi SilverDiscovery 3
Re- Ohms law and current measurement

The resistance of that fuse must be wrong at 2.5 Ohms.
Using Ohms law again, where Power (W) = (IxI) x R would mean the power dissipated in the fuse at 6 amps would be 6 x 6 x 2.5 = 90 Watts! That would melt the fuse and the fusebox in short order!
You could, in theory, measure the resistance of the fuse, ( it is likely in the sub 1 ohm region) then measure the voltage across the fuse while the pump is running to calculate the current by Ohms law. Since measuring very low resistances is difficult as it will change due to lead resistance of the meter, pressure applied etc, it might be easier to make up a probe using an old fuse and soldering wires to it so that the current meter could be inserted directly in line with the pump
  
Post #177101429th Jan 2017 3:00 pm
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Discoeast
 


Member Since: 19 Feb 2008
Location: Boksburg
Posts: 800

South Africa 2007 Discovery 3 TDV6 S Auto Zermatt SilverDiscovery 3
Re: Please help! Fuel rail pressure on a D3 (2007) EU4

Junds wrote:
Hello everybody,
We are travelling in Nepal with our D3 TDV6 2.7 and there is no assistance whatsoever. We try to figure out what the problem is and need some help.

Could someone please measure the fuel rail pressure in idle (700-800 rpm) and maybe 2000 rpm (not driving) with the IID Tool?
I can't find any reference anywhere.

My values are:
6000 kPa engine off
30000 kPa engine idle about 750rpm
>30000 kPa when faster

Does this sound ok?

What I don't understand are the 6000 kPa (60 bar!) when the engine is not running, because then there should be no compression in the high pressure pump. Is it a sensor offset? And is such a high offset ok?

I don't read any low/high pressure error codes, just the P0191 Fuel rail pressure sensor range/performance. This might cause the system error resulting in driving in limp mode.

Thank you!

I've run into this issue as well, using the Icarsoft diagnostic tool on live data the fuel pressure is measured in Mpa, so I was getting a holding pressure of 0.04 Mpa ( 0.4 bar ) and an idle pressure of 25/27 Mpa ( 250/270 bar ) on idle, put the word out on our local forum for others input and came back with the same pressures, also spoke to a local well known landy indy and he confirmed said pressures. I get the same fault code, so in conclusion I point the problem to the fuel pressure regulator and not the hp pump. What I have seen running the live data full time is that when the error occurs the idle pressure is between 30/32 Mpa, switching the engine off, removing the key, putting it back and just switching on the ignition the holding pressure is 7.1 Mpa, start and goes to 30/32 Mpa,and only when the holding pressure drops back to 0.04 Mpa will the engine run normal with no errors and the same goes for the idle pressure. In my case the error would kick in while driving, the engine would die, pull over and cycle the key a few times and be on my way, this happened 3 times and was gone for months. Then came back with a bang, where the engine would start, but would be in limp mode and would not get far as the power would start a gradual decline till you have none. As the pressure regulating valve, as per LR, is not a service item the pump was replaced.
 D3 bullbar-spots-roof rack with spots-ladder-long range tank-swing out spare wheel carrier- upgraded tow bar-dash console-internal water tank-duel awnings-drawer system & T T.  
Post #17738084th Feb 2017 8:54 am
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dd disco
 


Member Since: 08 Oct 2010
Location: S.E. Suburbs, Melbourne, Victoria
Posts: 9

Australia 2008 Discovery 3 TDV6 HSE Auto Stornoway GreyDiscovery 3

I replaced the lpfp during the week, the P0087 error went away however once again after approx 45 mins to an hour of driving I started getting P2290 (fuel injector pressure too low) errors, it seemed to be worse when the ambient temperatures were higher. Same issue with it sometimes coming up again after a few hundred meters and other times 30+ kms.

Today I bit the bullet and replaced the hpfp with a heap of assistance, since my mechanic friend insisted that was still the problem. I have been for a 2 1\2 hour drive since fitting in 35c temps and all seems to be fixed. I will report back if I have any further troubles.

Good luck in finding the resolution to your issue.

Daniel.
  
Post #17738194th Feb 2017 9:23 am
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