Member Since: 28 Nov 2018
Location: PENZANCE
Posts: 51
Fuel pressure regulator
Evening all. Following on from my thread about my Discovery 3 TDV6 taking longer to fire than it should I think I've found the cause. The fuel rail shows a pressure of 130 kpa (1.3 bar) engine off, my understanding is that this should be held by the fuel control valve on the high pressure pump at 100 bar. When cranking the pressure builds until at diagnostics showing about 9000 kpa it fires. This is below the injector trigger pressure but I think this is a delayed figure due to the diagnostics frame rate as once running it is about 22000 at idle.
This seems to suggest that the fuel pressure control valve spring has weakened. Is this a replaceable part it is it a new high pressure fuel pump needed? If the latter I'll live with it taking a bit of time to fire I suspect.
Thanks in advance.
8th Dec 2018 8:14 pm
hugeviking
Member Since: 08 Jun 2010
Location: cotswolds
Posts: 1482
I think leaky injector (s) can cause this as well, on the leakoff side.
Andi.
9th Dec 2018 2:33 pm
Ratty43
Member Since: 28 Nov 2018
Location: PENZANCE
Posts: 51
Thanks Andi, I'll have a double check that there's no leaks.
10th Dec 2018 11:38 am
hugeviking
Member Since: 08 Jun 2010
Location: cotswolds
Posts: 1482
I meant internally.
The injectors would need checking with a leakoff kit. But i am not entirly sure so check before spending any money. Hopefully someone on here will confirm
Andi.
10th Dec 2018 8:28 pm
Ratty43
Member Since: 28 Nov 2018
Location: PENZANCE
Posts: 51
I see your point, I had one that was well below specs which I thought might be the cause but it's made no difference sadly. I'll keep an eye on the oil level as an internal leak should show that way logically. Thanks for your help.
10th Dec 2018 9:17 pm
philm
Member Since: 02 Oct 2016
Location: Manchester
Posts: 732
Leak off test
L633 Defender
Range Rover Velar-gone
Discovery 4 Landmark-gone
Gap IID Tool
10th Dec 2018 9:33 pm
Ratty43
Member Since: 28 Nov 2018
Location: PENZANCE
Posts: 51
Thanks for that. I do think if I had a faulty injector I should have more symptoms though as other than starting it runs incredibly well. Worth investigating though as it seems the kits to do it are pretty cheap and I have a set of seals for the leak off pipes.
11th Dec 2018 8:40 pm
philm
Member Since: 02 Oct 2016
Location: Manchester
Posts: 732
Did my mates freelander with bits of tube into pop bottles.
His run great ounce started, just didn't like starting, two injectors leaking badly, change them and he's had no problems since.L633 Defender
Range Rover Velar-gone
Discovery 4 Landmark-gone
Gap IID Tool
11th Dec 2018 8:50 pm
Ratty43
Member Since: 28 Nov 2018
Location: PENZANCE
Posts: 51
That is very interesting, thank you for replying. I had really discounted the injectors as all are well within trim limits and it runs so well otherwise. Leak off test it is.
11th Dec 2018 8:53 pm
FakeTan
Member Since: 17 Aug 2017
Location: Cork
Posts: 39
Any update on a solution. I'm having the same problem.
6th Aug 2020 12:12 am
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4651
Can you provide more detail of exactly what's going on?yµ (idµ - eAµ) ψ=mψ
6th Aug 2020 1:16 am
FakeTan
Member Since: 17 Aug 2017
Location: Cork
Posts: 39
FakeTan wrote:
Any update on a solution. I'm having the same problem.
I've narrowed down the cause most likely to be the high-pressure fuel pump, less likely to be the low pressure fuel pump.
I just got pricing from an official dealer:
➤ Low Pressure Fuel Pump €1500 including VAT and labour (£1200 approximately)
➤ High Pressure Fuel Injection Pump and Drive Belt €1700 including VAT and labour (£1400 approximately)
6th Aug 2020 3:05 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4651
Quote:
FakeTan.
I just got pricing from an official dealer:
➤ Low Pressure Fuel Pump €1500 including VAT and labour (£1200 approximately)
➤ High Pressure Fuel Injection Pump and Drive Belt €1700 including VAT and labour (£1400 approximately)
They're not just pulling your leg there FakeTan, but more like having both legs off after they've first had your pants down. yµ (idµ - eAµ) ψ=mψ
6th Aug 2020 3:15 pm
FakeTan
Member Since: 17 Aug 2017
Location: Cork
Posts: 39
I have to agree with you
6th Aug 2020 3:32 pm
Lrsg
Member Since: 10 May 2020
Location: Norway
Posts: 77
Search ebay for a refurbished used hpfp. Should be available for £350-400. I just bought one.
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