TD5 cut out none start

hi guys,

I have took my engine out of my disco td5 auto & stripped it down, as it was leaking with oil from everywhere...replaced head gasket (wasnt gone in first place, just while i was there) and replaced seals all round. Now it is bone dry.

Drove it for 2 days not an issue, then on the motorway doing 70, no warning or noises, just died as though ran out of fuel. Just cranks over & doesnt even try to fire...tried bleading procedure umpteen times & nothing...one thing I can say is, my fuel pump sounds alot quieter than usual (i think) & usually when doing the blead procedure, i can hear the fuel purging into the head now i cant, i can hear something, but not what you usually hear.

Ive taken the fuel pipe of the fuel pressure regulator & when ignition on it does squirt out, but doesnt seam at a high rate as you would maybe expect?? also worth mentioning, i do have a nanocom.

Hi if no codes logged and you can see at least 250rpm engine speed input while cranking it can be that the pump is running only on LP which in some cases will not let it start either, a multimeter is needed to check that https://www.landyzone.co.uk/land-rover/check-td5-fuel-pump-hp.358086/

sierrafery said:

Hi if no codes logged and you can see at least 250rpm engine speed input while cranking it can be that the pump is runing only on LP which in some cases will not let it start either, a multimeter is needed to check that https://www.landyzone.co.uk/land-rover/check-td5-fuel-pump-hp.358086/

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thanks sierrafery,
love how your always the first the scene

I literally just wait for your replies lol...might aswel just title my threads to you haha...thanks pal, that was my thought that maybe its only running on low pressure, ive just came home to get the nanocom then going the unit to have a look. thanks mate

sierrafery said:

Hi if no codes logged and you can see at least 250rpm engine speed input while cranking it can be that the pump is running only on LP which in some cases will not let it start either, a multimeter is needed to check that https://www.landyzone.co.uk/land-rover/check-td5-fuel-pump-hp.358086/

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Ive checked the fuse F10 on 200mv setting...im getting 15.6 see pic attached

At that voltage IMO the engine should start even if the pressure is low but if the battery got weak from much cranking it can be normal so your problem is something else, charge well the beattery then check rpm with nanocom while cranking

Jaykay1987 said:

Ive checked the fuse F10 on 200mv setting...im getting 15.6 see pic attached

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and does voltage rise as you increase engine revs

im getting as follows

topside switch failed post injection
open circuit on injection x5

i put a new injection harness on it, when rebuilt...going to try my old injector harness back on.

Jaykay1987 said:

topside switch failed post injection

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Then struggle no more, you need a replacement ECU that's 100% sure...unless you are a very skilled electronist to fix your's

sierrafery said:

Then struggle no more, you need a replacement ECU that's 100% sure...unless you are a very skilled electronist to fix your's

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just changed injector harness back to normal & still getting same codes...what makes you say Its ecu? there wasnt any oil in the plug when i took it out during rebuild

I've seen myself topside switch failure not once, it's intermittent untill it ends up permannent and you'll be stuck with a non starting vehicle, google out "Td5 topside switch failed" cos it's full of info, here's a relevant one https://www.ecutesting.com/common-faults/land-rover/land-rover-defenderdiscovery-td5-ecu-fault/

sierrafery said:

I've seen myself topside switch failure not once, it's intermittent untill it ends up permannent and you'll be stuck with a non starting vehicle, google out "Td5 topside switch failed" cos it's full of info, here's a relevant one https://www.ecutesting.com/common-faults/land-rover/land-rover-defenderdiscovery-td5-ecu-fault/

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How do they fail, isit something ive done, or sh*t pot luck? as ive attached a photo, theres no oil made it in there at all!

My dad used to be an electrical engineer at delphi, retired now like...but sure he could help repair it, if we're half sent in the right direction... although i have just spotted a burnt out resistor, circled in attached.

Yes that resistor is part of the problem, nobody has a clear answer why this happens and it's no clear pattern for it. It's not your fault, it just happens

sierrafery said:

Yes that resistor is part of the problem, nobody has a clear answer why this happens and it's no clear pattern for it. It's not your fault, it just happens

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any idea where i could find a schematic or wiring diagram for nnn ecu, need to find the value of the resistor to replace it

NO such thing available for public...i've digged hard end never found

Jaykay1987 said:

any idea where i could find a schematic or wiring diagram for nnn ecu, need to find the value of the resistor to replace it

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Something has killed that resistor unfortunately. Just replacing it will not help, it will go up in smoke again.

when gettin a replacement ecu,

Mine is an 15p NNN 000130

but When getting an ecu, does it have to be the same numbers, or aslong as its nnn it will work?

The ECU must come from an Eu3 automatic D2 which afaik can be NNN000130 or 500030 or you can send your's to a specialist who has experience with them

Just a little update, took my ecu to mastaz in stockport, mans a genius...he repaired it, turned out he had to change a volt regulator, resistor & 16 pin chip as it was causing a short.