Member Since: 31 Aug 2014
Location: corona , CA
Posts: 25
HPFP - high pressure fuel pump
Hi everyone,
just wanted to share with you guys what I've been through hoping this information might help others,
i own a 2006 discovery 3 2.7 tdv6 with 210,000km on it, a month ago while i was driving the disco it went into limp mode, it was stuck in 3rd gear and wouldn't accelerate, switching the ignition off and back on didn't help, i was able to make it home driving at about 20 km/h, hooked it up to my IId tool and read the faults:
i tried clearing the codes but would come back immediately after start up and enter limp mode again.
used the live values option to read the HPFP pressure and this is what i got:
knowing that the pressure should be in the 20,000 kPa range i figured that the HPFP was at fault (most likely the pressure regulator wasn't working which is a solenoid attached to the HPFP), there was no access to the pressure regulator without removing the HPFP, the pressure regulator is located at the bottom of the HPFP (the newer models have the regulator at the top of the HPFP for easy access), so the pump had to come out, it took me about 6 hours to get the pump out (if i new it was such a hard job i wouldn't have bothered doing it myself), i disassembled the pressure regulator and hooked it up to power to see if the solenoid is working and i could clearly tell it wasn't working properly, searched everywhere on the web for a replacement but sadly couldn't find anyone who sells it. i ended up installing a refurbished pump which i purchased through ebay, once i put everything back together, i gave the ignition switch a try and it fired up right away, it was a bit shaky at idle but was finally out of limp mode, hooked up my IId tool to check the HPFP pressure and it was at 22,270 kPa which is perfect:
took the disco for a ride to see how it runs, after reaching operating temperature the car would accelerate perfect but was still shaky at idle, looking at the cylinder balancing offset values i could tell something is wrong with injector number 5 (the value was too high and not close to the other cylinders), i tried using concentrated diesel cleaner in the fuel tank hoping to solve the issue but that didn't help, to make sure that injector number 5 was the one causing all of the trouble i ended up doing a spill test:
these are the readings after 13 minutes while the engine was at idle:
injector 1 - 82 ml
injector 2 - 84 ml
injector 3 - 81 ml
injector 4 - 83 ml
injector 5 - 100 ml
injector 6 - 89 ml
the spill test did confirm that injector number 5 was at fault, i ended up replacing injector number 5 with a used one, and now the disco runs fine, here are the cylinder balancing offset values after replacing injector number 5:
now injector 4 is giving a high reading but the disco starts, runs, idles and accelerates perfect, so for the time being i wont be replacing anymore injectors.discovery 3 , 2006 , TDV6
15th Jun 2021 1:19 pm
discovery3ski
Member Since: 25 Dec 2012
Location: leicester
Posts: 735
That’s pretty clever. How much was a recon pump? Are they exchange?Discovery 3 tdv6 HSE 2007
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16th Jun 2021 8:02 pm
tareqyounis
Member Since: 31 Aug 2014
Location: corona , CA
Posts: 25
Member Since: 28 Jan 2021
Location: LEICESTER
Posts: 134
Good to see a diagnostic path being followed here.
The only things different I would have done is sent the pump off to a diesel specialist who would run the pump up for a proper test on on a test bench to confirm fault. I know this service is easily available in the UK, wouldn't know about in the States though
And its always possible a failing HPFP can create debris in the fuel system that then can cause previously good injectors to fail.
Be worth replacing the fuel filter now, and again in a couple of thousand miles.1994 Defender 300tdi 110 commercial
2007 Disco 2.7 XS Buckingham Blue
1959 Standard 10 Coffe & Cream
1974 Vauxhall Magnum 1800 estate Olivine Starfire Green
1994 Renault 19 Cabrio
1995 Kawasaki GPz 1100
17th Jun 2021 11:53 am
tareqyounis
Member Since: 31 Aug 2014
Location: corona , CA
Posts: 25
since i couldnt find anyone who sells regulators for this certain HPFP, i found a local diesel shop who said he could fix the pump for me, the diesel specialist confirmed it was the regulator but couldnt get his hands on one, diesel filter was replaced as well.
thanksdiscovery 3 , 2006 , TDV6
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