Member Since: 07 Oct 2011
Location: Oslo
Posts: 54
How to replace the HPFP
Was helping out a friend with his 2007 Discovery 3 that went into limp mode. IID Tool was showing the typical faults:
Changed the fuel rail pressure sensor but this did not make any difference. Measured pressure and Amperes as shown i Robbies guide how to check the low pressure fuel system but was getting enough pressure and LP pump drawing 5 Amps.
The car was hard to start, especially overnight. Sometimes it drove normal for several hundred meters before the whole Christmas tree of warning lights and messages like Engine System Fault, Transmission Fault etc. would show, sometimes immediately after using the throttle.
Checked the transmission ECU:
Mild corrosion - hope arose - cleaned everything with contact oxide cleaner and.... no difference.
Based on what I read on this forum I took the plunge and ordered an overhauled HPFP from Nerings.
Fantastic service, got one delivered within 24 hours after ordering.
Since I did not find a how to guide I'd like to share the experience of replacing the pump. The rear HPFP belt needs to be removed (and use the opportunity to renew) as part of the process.
This little friend proved to be invaluable:
Most challenging task is to remove the oil separator but once you know the trick it actually is not that difficult. Remove engine cover, then remove the coolant pipe that runs across the rear of the engine (2 hose clamps, 2 bolts holding the pipe to the engine hoist mount (10 mm head). Undo and remove both glow plug leads and move these to one side. Remove the rear plastic RH engine cover support "stick" as it will interfere with your arm later. Remove the intercooler hose from the throttle housing and undo the electrical connectors, undo both EGR pipes from the throttle housing by removing their clips and 2 small screws (8 mm head) holding the EGR pipes to the front timing belt cover, remove the big circlip and remove the bolt lower left corner throttle housing. Unclip diesel return hose and sensor from rear of throttle housing. Finally remove throttle housing. Remove metal bracket that holds the big wiring loom and is sitting over the rear HPFP cover by undoing 2 nuts (10 mm head). Bracket indicated by arrow.
Cut through the tape (2x) holding the cable loom to the metal bracket. Remove the metal bracket.
Undo both fuel hoses with quick connect couplers from both fuel pipes from HPFP and diesel return hose.
Click image to enlarge
(Be carefull as these are quite easy to break, as I did as you can see on the photo's later on) Remove the electric connector from the HPFP.
Remove the oil filter housing and cover the opening.
Loosen the clamp holding the hose to the rear of the oil separator, unclip the hose and push it backwards towards the bulkhead.
Remove 3 plastic tie wraps holding the injector cable loom and remove the gray cable support on each side of the engine. Left side of engine shown with cable support tray removed.
Undo one bolt (8 mm head) at the back of the engine (grommet) holding the left metal fuel pipe that runs from the HPFP to the LH fuel rail.
Remove the fuel pipe between the fuel rail and the last injector (nearest bulkhead) so you can undo the next fuel pipe.
Loosen both fuel pipe nuts (17 mm) (fuel rail and HPFP) and pull the fuel pipe to the left and away from behind the oil separator. This will create enough space to now remove the oil separator.
Pull the oil separator up using the provided tie wrap. Now push the round head backwards towards the bulkhead as far as you can, making sure the fuel pipe is out of the way and pushing the wiring loom backwards as well to create more room. Lift the RH glow plug "rail" from the glow plugs and move it a little to the front of the engine, just enough to create space.
Then, as indicated by the photo turn the oil separator counter clockwise so that its left "leg" gets out first. Photos show throttle housing still in place but I removed it later to create more space, it makes removing the separator a lot easier.
Then push and pull and rotate the separator until you manage to free-up its right "leg" as well and remove the separator from the engine.
Moving forward you now remove the cover of the rear HPFP belt and remove the bolt of the belt tensioner (10 mm head) and the tensioner and belt as well. Then proceed and remove 2 bolts (8 mm head) and remove the left part of the plastic belt cover to enable removal of the HPFP.
Now remove the RH fuel pipe from HPFP, first remove the grommet holding the pipe (8 mm head) and from the back of the RH fuel rail. Blue arrow shows broken fuel connector.
Using a mirror and a head light locate both torx bolts (T40) holding the HPFP to its mounting, and remove them.
Click image to enlarge
Click image to enlarge
Then remove both front bolts (10 mm head) holding the HPFP to its mounting.
You can now remove the HPFP from the engine.
The new HPFP comes without its gear. To remove the gear land Rover has a special tool, however I blocked the gear with a big screwdriver and removed the nut with an impact gun. The nut uses normal threads and loosens counter clockwise. The gear itself sits on a conical shaft, it lets itself easily remove with a bearing puller. Then move the gear to the new HPFP and whilst holding the gear with for example a screw driver use the impact gun to fasten the nut. Then move the electric loom from the old HPCU to the new one and secure its connector with a tiny tie wrap.
Installation is of course much easier as you know all the steps by now.
Lower the HPFP in its bracket, losely fitting the front bolts first and then the rear torx bolts. Use some loctite on the rear ones as shown.
Then tighten all 4. Install the left section of the HPFP belt cover. Install a new tensioner, then the belt, check with the mirror that everything is installed correctly and remove the locking pin from the tensioner. Install the plastic belt cover and fasten 3 clips.
Now the oil separator gets back in. It gets in the same way as it got out, with its right "leg" first.
Push the separator as far as you can forward and turn it until you get the left leg in as well and install it in place, making sure the rubber grommet sits correct (see arrow)
Put the glow plug power rail back on the glow plugs.
You can now install 3 metal fuel pipes back to both fuel rails and the HPFP and remember to put the grommets back. Then connect the hose on the rear of the oil separator. Now put the metal bracket that holds the cable loom over the rear belt cover back and fasten it with both bolts. Use tie wraps and secure the loom to the bracket. Then the coolant pipe goes back, throttle housing and other parts, connectors etc.
Just completed the job. D3 is fixed! All errors i saw the last couple of days were spin-offs from the main cause: Worn out HPFP. The following errors were present together with limp mode:
Engine System Fault (Message Center)
Transmission Fault + big F (Message Center plus F in speedometer Display)
Suspension Fault (Message Center)
Suspension Lowering
Limp Mode
To note is also the exhaust smell. When the HPFP plays up the exhaust is smokey and smells like unburnt diesel. When I purged the air out of the fuel system and started the engine for the very first time this evening I immediately noted the sweet smell of a Discovery TDV6 with a hint of chlorine, indicating proper combustion.
19th Mar 2020 10:30 am
ekkypoo
Member Since: 24 Sep 2009
Location: Guisborough
Posts: 202
great write. I'm just at the last bit of getting the breather out. How the hell did you get to the rear pipe clamp
Last one I did on a car park in Liverpool in the pouring rain, but like all jobs once you have done a few its straight forward.
Flack
29th Mar 2024 7:18 pm
Gareth Site Moderator
Member Since: 07 Dec 2004
Location: Bramhall
Posts: 26701
Great write up, thanks. 🙏 I’m sure plenty of people will find it very useful.
30th Mar 2024 8:51 am
ekkypoo
Member Since: 24 Sep 2009
Location: Guisborough
Posts: 202
yay it's out. The new volume regulator looks a little different to the one that is in. Checking with the supplier. Although the pulley is not "notchy" it seems just a little stiff, but easily turns by hand,is that normal? Just checking before i put it all back together
4th Apr 2024 3:22 pm
ekkypoo
Member Since: 24 Sep 2009
Location: Guisborough
Posts: 202
So i found this on the FVCV harness, which I am almost certain was causing my original p0003 code issue.
Click image to enlarge
Everything back together nor but back at crank and wont start and getting p0191 fuel rail pressure sensor/performance. checked all fuses etc and not getting any pressure at the shrader valve, which i was before. rechecked the low pressure side and and all looks ok (I have replaced the pump) and you can hear the pump whirring away.
are there any pitfalls when putting it all back together that IO may have missed. spent a lot of time on this one so its head scratching time
6th Apr 2024 1:43 pm
ekkypoo
Member Since: 24 Sep 2009
Location: Guisborough
Posts: 202
Actually cannot hear the pump whirring. Checking the wiring as shown attached. There is continuity from the fuse to the branch of the wire to the EMS (highlighted). The only thing I can think of is that the new in tank pump I bought has failed, or that in the work on the HP fuel pump, when I was moving the harnesses around has somehow broken the wire going to the LP pump. Any idea where this wire routes to? I have found another WP wire on the other side of the engine but I am almost certain that leads to the generator
Click image to enlarge
6th Apr 2024 4:34 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4651
ekkypoo wrote:
So i found this on the FVCV harness, which I am almost certain was causing my original p0003 code issue.
Click image to enlarge
I did advise you in your other threads to check the wiring carefully before condemning the HPFP!
That looks to be the cause of the fuse blowing, but once you repair it (solder splice) and heat shrink the joint it will be fine.
As for the lpfp it's possible the relay is damaged, so try swapping another relay (black) from a neighbouring component in the BJB but only after you have repaired the wiring! Alternatively, a fused bridge on the contacts as per the image below. Don't get this wrong or you'll be needing a new PCM. This bridge will allow you to continuously run the pump outside of the timed PCM limit, and allow you to prime the system fully as far as the HPFP. It doesn't need to be as elaborate as the one in the image, just a fused and preferably switched bridge with spades at either end.
Click image to enlarge
yµ (idµ - eAµ) ψ=mψ
6th Apr 2024 6:09 pm
ekkypoo
Member Since: 24 Sep 2009
Location: Guisborough
Posts: 202
thanks again for the input. I can confirm that the LPFP is working, I have connected everything back as it was but I am still not getting fuel at the shrader valve. When I disconnect the fuel lines and turn ignition on I get fuel out of this pipe
Click image to enlarge
I have replaced the FVCV with one supplied by PF Jones. It was slightly different to the one I took out in that the holes were on the opposite side but they assured me that it was compatible. My question is that does the fuel coming from the tank go to the shrader valve first before the pump, or on the way back? If the orientation of the holes is an issue would that mean that fuel will not flow back to the tank, hence no pressure
Click image to enlarge
Click image to enlarge
7th Apr 2024 9:34 am
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4651
I have only ever replaced complete HPFP's so I can't offer you any advice on the sensor you bought.
It often does take a long crank for the HPFP to fill the rails and pipework. So make sure you have a fully charged battery and let the starter swing for 10 to 15s.
You may need more than one attempt and if it still won't fire you could try a sip of Easy Start.yµ (idµ - eAµ) ψ=mψ
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