Range Rover L322 4.4 V8 petrol fuel pump diagnosis at JAS LR with Picoscope!

Time for some in-depth nerding!
40 minutes of nerding 😅
All electrical components have an electronic signature that can be read with the right equipment...understanding that signature and interpreting it correctly can be a very powerful diagnostic aid.
Granted...there are many ways we could have diagnosed this particular fault, but techniques like this can be applied across the board and used to diagnose other faults too!
If you know what you’re doing 😇

[@SuffolkCraftsmen]

Hi Joe, 4 years on I found this video after fixing my 05 l322 that had the same problem. the HP injector pump senses the lack of pressure on its feed and if its just dropped a bit will put the engine into low power mode with the 'Fuel Injector Fault' on the dash, if the feed pressure drops any further it cuts the engine to stop the HP pump running dry. fixed in 30 mins with a new in tank pump! Also, thanks for the insight into the difference between the BMW and LR relays, my 03 has the BMW ones and the 05 has the LR ones!🤣

[@heyitschinoable]

Well made video! You are well knowledged

[@jetskirob9779]

Thanks for the video a great help

[@michaelchristofi3213]

That's the reason they charge you the earth, messing about with diagnostics, basically knowing and having knowledge of the common error with range rover fuel pumps. Well, that's another £500 added to your bill! 😂

[@Ian-ij4of]

I'd like to see a short video on how to remove the two fuel line clips that attach to the fuel pump, I managed to get them both off today but it took about half an hour, they were a pain in the behind, I think it's the same clips on the fuel filter, I'm kinda dreading that...so yes a nice video on how you remove those fuel clips would be great...
Thanks.
Ian

[@Mike-yq6jg]

another great vid ,off the track a bit have you ever turned off or by passed the front air bag in a 55reg freelander ,we went to fit the baby seat and found theres no way of doing so .

[@johnshuttleworth6879]

Awesome video joe just out of interest at what other point in the circuit could the low amp clamp be connected in the absence of the specialist relay current loop tool to get the same waveform ?

[@joehodgy]

Hey John 👍👍
You can just make a male spade to male spade jumper lead and use that - the relay things are available from Mac if you want them :)

[@kevwatkins]

Awesome video as always Joe! Thank you! Why do you think that two out of the eight the commutator segments are drawing less current? Do you think this is just down to tolerance or could it be an impending future failure?

[@joehodgy]

Kevin Watkins hiya and thanks!
Yeah at a guess just a slight difference in manufacture of those segments and/or a difference in the windings attached to them - it could even be the pumping elements that the motor drives are less effective at the point where we have the lower current - every motor I’ve ever scoped has had an identifiable repetitive pattern - not always 2 lower peaks in a row...but always something :)

[@juancarlosromero1862]

​@@joehodgy😊😊

[@markpewsey]

Fascinating.
Out of interest Joe, did you consider it could be some kind of issue with the LPG side conflicting with the petrol? Sorry, I have no real idea how they work, other than being separate systems that come together at some stage.
Or was the car running fine on LPG, just not on petrol, along with the nasty sounding fuel pump?
Really impressed though how you can prove/disprove exactly what is going on.

[@joehodgy]

Mark Pewsey hi! Yes we did consider it! The LPG system on this car is connected to the petrol fuel pump circuit but purely by way of a changeover relay that either connects or disconnects the fuel pump relay switching circuit - ie if the LPG system is “allowing” the engine control module to control fuel pump operation then the original fuel pump circuit should work as intended 👍
You’re right though - definitely something that we needed to consider ☺️ the LPG system also piggy-backs off the original injector wiring ... so if we had misfires and poor running due to an injector fault (for example) then we’d have needed to go a bit further in depth with the LPG installation 👍

[@markpewsey]

@@joehodgy Thanks for that. As an exercise in demonstrating what Picoscope can do for you that was spot on. I have no need for one but, boy, do I want one!!

[@joehodgy]

Mark Pewsey not forgetting that in the real world it would have taken minutes! Thanks for the replies ❤️

[@markpewsey]

@@joehodgy lol, not at a main dealer workshop!

[@MrBLANNY1]

hi do you have apart number for them relays please .

[@gerrygorman273]

Hi would a failed fuel pump on my 08 tdv8 not start my car even with easy start, I can hear pump running underneath, only a,squirt of fuel from schrader valve when not crancked, then loads under crank.
Cheers
Gerry

[@RPAUTOS]

Hi joe where did you get those relay current loops from?

[@joehodgy]

Rick's Auto Shop hey! These were from MAC Tools 👍👍