TD5 Fuel Pressure problem

If nothing else, owning a LR helps you develop a sense of humour! Ran ok all day then started to take longer and longer cranking to start from hot. Got home afer 50 mile drive and switched her off. Had a brew came to start up and wouldn't fire. Cranked fine so not battery, but only started using jump leads off my 2.0 diesel car �� the extra "juice" enough to fire her up...
I think the starter motor is pulling too much current and depriving the pump of power. I am fitting a new starter at the end of the month after my hols, to see if that cures it! I have also read about electro-magnetic fields affecting the crank sensor when a starter motor is worn on TD5s, so makes sense as looks original.
Keep you posted
Andy

First of all when it makes the trick again measure the voltage on the battery while cranking cos if it drops below 10.5V then it becomes hard or impossible to start, it's not about depriving the pump's power but the ECU doesnt open the injectors with low voltage while the starter will happily spin even with 9V... make sure the alternator is properly working (around 14V on the battery at idle) and if it is IMO get a powerfull battery before you replace the starter cos if it was crank signal disturbance it wouldn't have started jumped either.

If the voltage is good you should plug in a tester though to read the FT(fuel temp) sensor's input(or just replace it cos it's not expensive), this sensor's erratic input can give hard starting symptoms cos when the engine is hot the battery is supposed to be charged by the alternator so it might not be a voltage but a management issue, also if it's crank signal problem there should be a "noisy crank signal" fault code logged

Thank you and a different take on the problem
I will change the temp sensor as cheap enough and not something I had considered. What difference would this make if faulty to the way it starts, under/overfueling maybe?
I have never had any crank sensor messages, which suggests that is OK. Would i get a message though if the starter was only interfering through magnetic disturbance? I will look again at the battery voltage when cranking, although it is a brand new HD battery and i was getting around 13/14 volts with the engine running at idle on the old battery. What i cannot fathom is why with the assistance of a jump start it wil start! This is why i am looking starter motor based on current draw.
I am away till 23rd so will update you once i sort this.
Thanks again
Andy

Andy Springthorpe said:

Thank you and a different take on the problem
I will change the temp sensor as cheap enough and not something I had considered. What difference would this make if faulty to the way it starts, under/overfueling maybe?
I have never had any crank sensor messages, which suggests that is OK. Would i get a message though if the starter was only interfering through magnetic disturbance? I will look again at the battery voltage when cranking, although it is a brand new HD battery and i was getting around 13/14 volts with the engine running at idle on the old battery. What i cannot fathom is why with the assistance of a jump start it wil start! This is why i am looking starter motor based on current draw.
I am away till 23rd so will update you once i sort this.
Thanks again
Andy

Click to expand...

to refresh my memory I have re read some comments but not all
you have mentioned you had 7 bar of pressure 100 psi from the fuel pump this is not possible .....I do agree the pump its self can produce 100 psi of pressure so unless you plugged direct into the fuel supply without a T piece this will give max pressure what the fuel pump can supply
now giving the fact the fuel pump is under high pressure pulling max amp load any voltage drop will show on the pressure gauge
based on current draw

before purchasing a new starter use the jump leads once again but only this time using the vehicle battery to by pass any bad connections or bad wiring

for example connect the jump leads from exiting battery direct to the starter motor as well as the earth cable ..also run this same test direct power to the relay box using the existing battery giving the fact every connection gas been cleaned

I wouldn't really worry about your fuel temp sendor but if your in doubt disconnect it then try ..mine still starts and runs disconnected

my charging is normally 14. to 14.5 at idle consistent my aux batt in the rear sees 13 /14 consistent due to power loss length of leads

Right, back off hols and did some electrical testing. Battery on charge all night, shows 13.22 volts, with ignition glow plugs and pump running drops to12.60 . When cranking dropped to 11.66, but didn't start. Second attempt battery now at 12.95, drops to 12.6 then to 11.25 when cranking but started after around 5-7 seconds. Ran engine for 5 mins alternator charging at 14.35 volts.
Switched off and tried restart, 13.2 drops to 11.3 starts after 5 secs cranking.
Connected jump leads, now at 14.10 volts but drops to 12.3 when cranking starts after 3-4 secs. Repeat same figures. Once running, no issues and faultless.
Is a 2 volt drop when cranking excessive, and could this be my problem, i.e. starter drawing excess volts/amps and either interfering with crank sensor or ECU so it doesn't fire injectors. Or is it more likely the crank position sensor playing up, I can't check this for couple of days though
Thoughts please.
Thanks
Andy

Update Hip Hooray it is finally sorted! Having left it 3 weeks due to holiday it came as no surprise that it wouldn't start. I went with swapping the crank sensor first. The old one was very oily and you couldn't see the sensor tip! However the recess it fits into was clean which surprised me. . The O ring was not present either which probably didn't help. I fitted a new CPS and it started, but still required some cranking. I then changed the starter motor, top bolt a fiddle but got there eventually. She started first turn of the key, with less than a seconds cranking. Switched off left it and tried again after 5 mins, immediately started. No doubt all the other things I have done have contributed to finally sorting this problem, but it certainly looks like the starter was the main culprit.
Thanks everyone for your advice and support. It has took a while but I finally got there in the end.
Kind regards
Andy

Mine is the same strggles to start when fuel less than half. I'e put a genuine New fuel filter housing with filter air value and non return valve fitted. New aftermarket fuel pressure regulator. New aftermarket fuel pump and now its got a second hand genuine fuel pump. Injector loom replaced and injectors seals done a not long ago. Don't know what else it can be please help

My issue was the same regardless of fuel levels, however, why not change the CPS for new one as not hugely expensive and see if this helps. If not then a new starter motor fixed mine.

What' CPS crank possision sensor?

Andy Springthorpe said:

why not change the CPS for new one as not hugely expensive and see if this helps. If not then a new starter motor fixed mine.

Click to expand...

That would depend on if you want a reliable one, the cheap ones are not reliable apparently and a genuine one is approx £225:00 as being discussed here:

https://www.landyzone.co.uk/land-rover/td5-crank-position-sensor.326635/