purchased my first land rover few weeks back and was running great,
3 days ago i ran a errand to the store and drove back home perfectly.
next morning, it cranks until it stops on its own and wont start. has no faults codes, battery was almost new, all fuses underhood are good. i tried jump starting it thinking battery might be bad, but just keeps cranking. i have read it could be a crank or cam sensor, but wouldnt they show in the fault codes?
any advise would be great before it gets towed to the get serviced, thanks in advance.

 

Many possible causes for this.

Most common is fuel. Both the pump going out, or the fuel level sending units failing, causing it to read that there is gas in the tank, but it's actually empty. Step one, unless just recently filled up, would be to throw a few gallons in the tank.

I have also seen several times where carbon build up on the throttle body will not allow enough air to flow in while starting, which will cause the engine to flood out. Try pressing the throttle down half way(all the way will cut all fuel delivery) while cranking and see if it tries to start, if so, expect a fair amount of smoke.

What year and engine?

 

its a 2005 V8 4.4 HSE.
it has a new fuel sending unit replaced 4-5 weeks ago, i would read empty all the time.
i will try hold the gas down half way thanks.

 

after trying to start it with throttle half way i get a message in the display
"HDC FAULT SYSTEM NOT AVAILABLE'
checked the manual but does tell me how to fix it. the vehicle was in the driveway when this issue began but now its on a flat surface on the street.

 

The HDC fault is most likely the battery getting weak from cranking, but not the main concern here.

Did it try to start at all with the throttle depressed, even a stumble?

 

Your comment on the fuel gauge intrigued me. Some time back, an owner in Africa had a temperature gauge that most often either was showing full hot or full cold.

Bottom line was his 3 would just stop for no reason and then later start again.

It turned out to be that the big electrical connector plugging into the rear of the instrument panel was loose - why, no one knows, and the only indication was the temperature gauge acting up. Replugging it resolved a year of ownership frustration.

The reality is that there is a backup memory chip for what I will call the engine computer and LR calls the ECM, mounted on the instrument panel printed circuit board. No backup memory, no start if seems. Well, it would crank, it just would not start.

 

the dealer was able to fix it, and turns out it was the fuel pump relay. weird because i would hear the pump but wouldnt feed to engine? funny thing after that was fixed now my fuel sending unit it bad, after it was replaces about weeks before. it would show always empty and now after the fuel sending unit relay was replaced it, empty is is at 1/2 way....

 

I do not know if the two pdf's below may help but they do explain the operation of the fuel system a bit.

This 6 page pdf below shows the Fuel Purge Valve and associated hoses and describes how it is supposed to work. There are lots of good drawings of the fuel system. It is more complicated than one might think - well maybe you have too good an introduction to it already.

http://www.disco3.co.uk/gallery/albu..._Operation.pdf


This 10 page pdf below shows views of the fuel tank internals, what the various pieces do and describes how the fuel storage system is supposed to operate.

As usual, you can download it, save, and print as required.

http://www.disco3.co.uk/gallery/albu..._Operation.pdf