Advertise on DISCO3.CO.UK
Forum · Gallery · Wiki · Shop · Sponsors
DISCO3.CO.UK > Technical (D3)

Fuel Pressure (Solved)
Post Reply  Down to end
Page 1 of 2 12>
Gazza_Magoo
 


Member Since: 20 Apr 2015
Location: South Australia
Posts: 8

Australia 2006 Discovery 3 TDV6 HSE Auto Zambezi SilverDiscovery 3
Fuel Pressure (Solved)

Hi everyone, I have recently bought a Discovery 3 TDV6 2006 HSE and now have the following problem.

The engine cranks but won't start unless it gets a sniff of aerostart (cold or hot engine)
Fuel pressure on cranking is only 9,000 kpa so from what I have read this is not enough to activate the injectors as they need 150 bar (15000kpa). So Problem isolated to fuel rail pressure, however cause of this unknown. I have done the following checks

- Battery is good and cranking speed is ~200rpm
- Fuel filter replaced
- LP fuel pump is supplying 7 psi up to the check valve.
When the car starts fuel rail pressure is ~22,000kpa on idle(750rpm) and 59,000kpa at 2700rpm.

The car drives a bit rough as the engine surges, no misfires or anything and if I accelerate hard I will get an engine fault/ limp mode. This clears with a restart. This surging can also be observed in park when holding engine revs at ~2000rpm on a cold engine. The surging almost completely goes away when the engine warms up and then it drives well. I can still get an engine fault if I accelerate real hard for a while.

From all my research on this site it could be HPFP or LP FP.

Could anyone please advise of an additional check for the LP Pump before I buy one and fit it just to rule the cheap option out before I go down the HPFP path.

The engine is only 30,000 old. It was a complete long engine with everything except alternator, starter motor and air conditioner.

Appreciate any advice on this
Garry

 

Last edited by Gazza_Magoo on 15th Jun 2015 11:14 am. Edited 1 time in total 
Post #147835425th May 2015 11:27 am
View user's profile Send private message View poster's gallery Reply with quote
Lost for Words
 


Member Since: 03 Sep 2013
Location: Warminster, Wiltshire
Posts: 6375

United Kingdom 2006 Discovery 3 TDV6 HSE Auto Zambezi SilverDiscovery 3

Welcome. Thumbs Up

Have you checked the injector values? If so, what did you get?

I think, 7 psi from the LP pump is fractionally low but not too far off.
 Current: Discovery 3 06MY (55 reg) HSE Auto Zambezi Silver Zambezi Silver Allisport Fast Road Intercooler, V8 Brakes, Silicone IC Hoses, EGRs Blanked, Remapped, De-Cat pipe, FBHIC
Freelander 2 2007 HSE Manual Tambora Flame
Previous: FL2 56 reg SE Manual Black (written off Sad )
Disco 3 06 reg B7S Manual Rimini Red Rimini Red
Disco 2 TD5 Y reg ES Manual Blue - Chipped Very Happy
Several Discovery 300 TDis
 
 
Post #147836125th May 2015 11:43 am
View user's profile Send private message View poster's gallery Reply with quote
Gazza_Magoo
 


Member Since: 20 Apr 2015
Location: South Australia
Posts: 8

Australia 2006 Discovery 3 TDV6 HSE Auto Zambezi SilverDiscovery 3

Thank you Thumbs Up
No check on the injector valves at this stage.
  
Post #147838225th May 2015 12:21 pm
View user's profile Send private message View poster's gallery Reply with quote
Robbie
 


Member Since: 05 Feb 2006
Location: Waiting for my old avatar to be allowed back... we miss her!
Posts: 17537

United Kingdom 2013 Discovery 4 3.0 SDV6 HSE Auto Baltic BlueDiscovery 4

Don't forget the basics such as sensor data, including ECT and oil temps as these are used during start. It would be good to know that the glowplugs are working correctly too.

Thumbs Up
 Land Rover - Turning Drivers into Mechanics Since 1948

Battery & Quiescent Current Drain Testing

Diagnostics for:
Defender, FL2, D3, D4, Evoque, RRS & FFRR
A not-for-profit enterprise


 
 
Post #147838925th May 2015 12:44 pm
View user's profile Send private message View poster's gallery Reply with quote
Gazza_Magoo
 


Member Since: 20 Apr 2015
Location: South Australia
Posts: 8

Australia 2006 Discovery 3 TDV6 HSE Auto Zambezi SilverDiscovery 3

Thanks Robbie
After reading many other threads on this and other sites I decided to remove the tank and pump.
I checked the amp draw at F1 this was only 4.1 amps, oil temp and sensors working.

Tank and module out...pump is the walbro GSS503.

Any tips on taking the black fuel line off the LP PUMP. I spent a while trying to free this up and remove, didn't want to go to hard and break something.

Thanks
  
Post #147900226th May 2015 12:47 pm
View user's profile Send private message View poster's gallery Reply with quote
Robbie
 


Member Since: 05 Feb 2006
Location: Waiting for my old avatar to be allowed back... we miss her!
Posts: 17537

United Kingdom 2013 Discovery 4 3.0 SDV6 HSE Auto Baltic BlueDiscovery 4

Sorry I've only done this once and that was years ago with 2 of us at it and neither of us particularly had a clue as to how it was all going to go. I don't recall the workshop manual being that helpful either when it came to remove the clips and lines.



4.1 amps does not sound too bad at all if the fuel is reasonably warm. 7 PSI is not bad either and I have seen them start with a lower figure.

The book figures are:

50 kPa (0.5 bar) (7.25) lb/in²

You can also do a flow check to see how much fuel comes through in a given time. The ideal is around 70 litres an hour ~ 1666 ml a minute.

Thumbs Up
 Land Rover - Turning Drivers into Mechanics Since 1948

Battery & Quiescent Current Drain Testing

Diagnostics for:
Defender, FL2, D3, D4, Evoque, RRS & FFRR
A not-for-profit enterprise


 


Last edited by Robbie on 26th May 2015 1:23 pm. Edited 2 times in total 
Post #147900526th May 2015 12:56 pm
View user's profile Send private message View poster's gallery Reply with quote
Gazza_Magoo
 


Member Since: 20 Apr 2015
Location: South Australia
Posts: 8

Australia 2006 Discovery 3 TDV6 HSE Auto Zambezi SilverDiscovery 3

No worries Thumbs Up
I have removed the module from the tank as pictured in your post. The lines that clip on are easy to remove. The problem one is a barbed outlet from the pump and a hard plastic line to the manifold for the regulator.
I sure with some more perseverance tomorrow all will be well
Thumbs Up
  
Post #147901426th May 2015 1:20 pm
View user's profile Send private message View poster's gallery Reply with quote
Gazza_Magoo
 


Member Since: 20 Apr 2015
Location: South Australia
Posts: 8

Australia 2006 Discovery 3 TDV6 HSE Auto Zambezi SilverDiscovery 3

Flow check ~ 3L / min so I guess that rules out the LPFP, all looked ok with the pump filter, nice and clean.
Just finished fitting the fuel pump back in the tank (bit awkward) and tank installed back in the car.
Car runs just as before......no start on crank unless assisted with aerostart.

Just wondering could it be an injector leaking and therefore preventing the HPFP reaching the required fuel rail pressure for start up?
  
Post #147947527th May 2015 12:11 pm
View user's profile Send private message View poster's gallery Reply with quote
Robbie
 


Member Since: 05 Feb 2006
Location: Waiting for my old avatar to be allowed back... we miss her!
Posts: 17537

United Kingdom 2013 Discovery 4 3.0 SDV6 HSE Auto Baltic BlueDiscovery 4

A healthy HPFP could easily overcome the effect of a leaking injector - remember that almost all the fuel output from the HPFP goes back to the tank.

With a low rail pressure and healthy LPFP it does look like the HPFP is at fault. As the sensor readings appear to match your symptoms it does not look like a sensor issue either. As the PCV and VCV appear to be responding to ECM commands then the PCM itself looks ok.

So I think we are left with a mechanical HP pump issue or a bad PCV; perhaps contaminated or partially blocked. It is possible to test the resistance on the valves (1.5 to 15 ohms) but I would have expected a fault code for the rail pressure so I am scratching my head a little.

I've not seen a bad HPFP outside of a petrol misfuel event so perhaps someone with more experience can offer their thoughts.

Thumbs Up
 Land Rover - Turning Drivers into Mechanics Since 1948

Battery & Quiescent Current Drain Testing

Diagnostics for:
Defender, FL2, D3, D4, Evoque, RRS & FFRR
A not-for-profit enterprise


 
 
Post #147949627th May 2015 12:53 pm
View user's profile Send private message View poster's gallery Reply with quote
lynalldiscovery
 


Member Since: 22 Dec 2009
Location: Maidstone
Posts: 3918

United Kingdom 2006 Discovery 3 TDV6 Metropolis LE Auto Bonatti GreyDiscovery 3

Not sure on disco, but used to be dead common fault at work a for an injector with excessive leak off preventing engine start, they used to start them the same way as you easystart etc and they would run fine all day long until you switched them off again!
Leak off test kits for 6 cylinders on ebay 40 quid.
Ive even seen people just remove the leak off pipes and crank the engine and whichever injector Censored the most diesel out got replaced and that fixed it.
  
Post #147957327th May 2015 4:22 pm
View user's profile Send private message View poster's gallery Reply with quote
Robbie
 


Member Since: 05 Feb 2006
Location: Waiting for my old avatar to be allowed back... we miss her!
Posts: 17537

United Kingdom 2013 Discovery 4 3.0 SDV6 HSE Auto Baltic BlueDiscovery 4

For interest, my D4 fuel pressure at idle:

Click image to enlarge
 Land Rover - Turning Drivers into Mechanics Since 1948

Battery & Quiescent Current Drain Testing

Diagnostics for:
Defender, FL2, D3, D4, Evoque, RRS & FFRR
A not-for-profit enterprise


 
 
Post #147957827th May 2015 4:43 pm
View user's profile Send private message View poster's gallery Reply with quote
Gazza_Magoo
 


Member Since: 20 Apr 2015
Location: South Australia
Posts: 8

Australia 2006 Discovery 3 TDV6 HSE Auto Zambezi SilverDiscovery 3

Thanks for the replies. I think I will pursue the injector path fist before the HPFP. Took it out for a today, surging whilst cold but once all was warmed up the car ran well. I give it a boot full and got the check engine fault. Codes were low fuel rail pressure. I will let you know how I go with the injector tests.
Thanks again for all the help Thumbs Up
  
Post #147997628th May 2015 1:40 pm
View user's profile Send private message View poster's gallery Reply with quote
Gazza_Magoo
 


Member Since: 20 Apr 2015
Location: South Australia
Posts: 8

Australia 2006 Discovery 3 TDV6 HSE Auto Zambezi SilverDiscovery 3

Well all fixed now. Turns out it was the HPFP. New one fitted and she starts again first time and no surging at all. I can accelerate at full throttle with no engine faults Very Happy
Thanks for helping out guys.
  
Post #148740114th Jun 2015 10:42 am
View user's profile Send private message View poster's gallery Reply with quote
Robbie
 


Member Since: 05 Feb 2006
Location: Waiting for my old avatar to be allowed back... we miss her!
Posts: 17537

United Kingdom 2013 Discovery 4 3.0 SDV6 HSE Auto Baltic BlueDiscovery 4

Glad it is all fixed and thanks for the update.

Thumbs Up
 Land Rover - Turning Drivers into Mechanics Since 1948

Battery & Quiescent Current Drain Testing

Diagnostics for:
Defender, FL2, D3, D4, Evoque, RRS & FFRR
A not-for-profit enterprise


 
 
Post #148740714th Jun 2015 10:56 am
View user's profile Send private message View poster's gallery Reply with quote
Dartmoor Dave
 


Member Since: 08 May 2017
Location: South West
Posts: 17

United Kingdom 

I've come in on this very late but because I'm wrestling with my neighbours D3 LPFP I got the hose off the pump barb fairly easily by washing the fuel away with cleaner and warming, I said WARMING, the end with a hot air gun when it relaxes a bit and can be wiggled off. It goes back on tight enough on the next pump.
  
Post #184592610th Aug 2017 10:51 am
View user's profile Send private message View poster's gallery Reply with quote
Display posts from the last:  
Post Reply Back to top
Page 1 of 2 12>
Jump to:  
Previous Topic | Next Topic >


Posting Rules
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum



DISCO3.CO.UK Copyright © 2004-2017 Futuranet Ltd & Martin Lewis
DISCO3.CO.UK RSS Feed - All Forums Follow DISCO3.CO.UK on twitter

DISCO3.CO.UK is independent and not affiliated to Land Rover.
Switch to Mobile Site