I finally found some time to spend on the rrs today so I thought I would give an update for anybody interested, I went for a drive in it first and it started instantly as usual, it drove faultlessly and didn't hesitate or give any reason to think there was anything wrong at all which is a vast improvement since replacing the pump module in the tank. I stopped for around half hour and when I came back it wouldn't start and was just spinning over furiously, after around 2 mins it started up like nothing had happened at the end of about a 30 second cranking session I then drove home without fault and turned it off and it refused to start, I set about checking it over and started with the fault codes the only fault shown since replacing the lp pump is p0191 which comes straight back as soon as it cranks over for any length of time so I decided to scope the rail pressure sensor which was spot on but in the process I flattened the battery cranking it and as soon as I connected my booster it started instantly so I kept shutting it off and re trying it and with the booster there was no p0191 and it would start but without the booster no start and p0191. Also if the booster was turned on whilst cranking there was an instant spike in fuel pressure on the scope and it would start right up.
Now I know the battery subject has been covered a million times and I thought I'd ruled it out earlier but the lp was obviously causing the starting issues at that point but can it really be that simple? I guess we will find out tomorrow as I have a Bosch S5 on order just to be sure,
Failing that has anybody heard of the crankshaft sensors giving trouble and causing fuel rail codes only I had a diesel transit come in that wouldn't start without a jump even though the battery was good and that was the ckp sensor

Battery didn't help but it still starts fine with the jump box attached and not without it after the initial start up, When monitoring the live data with the iid the fuel pressure is exactly the same with or without the jump box so I'm now certain the P0191 is just a spoof code and the fuel pressure is fine which now has me convinced it's the crankshaft sensor but I will have to scope it when I have more time as it looks like a pig of a job to replace so I want to be certain.
Also to note the battery voltage with new battery is 10.6v when cranking and 11.1v with the battery and booster together which I would consider normal but open to opinions.
The new battery is 110ah and 920cca
The booster is 1200cca and 3000amps peak Clickadeeclick

I had the rrs on the lift today and located the crank sensor and all I can say is WOW, I also spoke with a friend from Lr and he told me that it's possible to do it without removing the gearbox and sent over some details of how to do it but tbh it looks easy from his how 2 but tbh in practice I can't see that it can be done as it showed that you removed the starter & cat heat shields (done) then remove the turbo support bracket 5 bolts and this is where the picture he sent wasn't to clear but looking on the car there ain't no way I can see to get at 1 bolt as it's right behind the turbo against the block and even if you could get a spanner on it and somehow turn it then you would run out of room before the bolt came out as there's only around 8mm between the bolt & turbo so unless I'm missing something im wondering if the how 2 is for a ffrr or something.
If anyone has any experience with this then feel free to give your opinions or even better if anyone has the how 2 with a clearer pic of the 5 bolts I would be grateful and in the meantime I will try and post a pic of mine Clickadeeclick

I finally had some more time to look at the rrs today so I thought I'd scope the crankshaft sensor due to the amount of work to replace it, the results weren't what I expected the car started perfectly from cold and had a perfect square wave so I let the car warm up until it wouldn't start and it still had the square wave with no drop outs etc so I'm now at a loss as it still starts fine with the booster connected and the battery is new and the ecu voltage is the good when cranking the fuel pressure is the same at cranking when it starts and when it doesn't. Any ideas welcome? Clickadeeclick

Maybe it's time to trade it in for another ffrr!! Clickadeeclick

Oh no you won't like the FFRR handling after the RRS, very rolly polly unless you go for a supercharged one which has the Dynamic Response handling pack that TDV8 RRS and S/C RRS have. I went from TDV8 RRS to TDV8 FFRR Vogue in 2010 and while the inside trim was beautiful (much better than the RRS)the handling and stopping isn't a patch on a TDV8 RRS 2020 Pangea Green 1st Edition D240 New Defender 110 is here and loving it
2018 Melting Silver Mini Countryman PHEV - soon to be replaced
2015MY Corris Grey SDv6 HSE Dynamic, the best car I have ever owned, totally reliable only a cou0le of rattles in 3 years, now no longer in my care
Also in my garage is a 1996 TDi300 Defender 90 County HT made into a fake CSW

Your probably right as I would probably have to go for an earlier td6 but it's just frustrating not being able to use it, I've toyed with wiring up my boost box permanently lol, Clickadeeclick

Well after some deep thought about the options I have left with the rrs I have decided I need to rule out for certain a few components that I have previously ruled out as I felt sure they wasn't the cause of my problems. The first thing on the list is the starter motor and it's going off to be tested so I decided to quickly pop it out ....... ahem well er why do we all love these things so much? I just wished I'd realised what was involved as I would have took some photos, it probably only took about an hour or so but aside from the usual starter related bolts/wires I had to take the fuel pipes to the cooler off and disconnect the hydraulic pipes to the anti roll bar before a long battle with manouvering the starter out, I just can't wait to try and get it back in

Also while doing this I realised the heat shield for the starter was missing which got me thinking could the heat from the turbo be overheating the starter causing it to draw more current??

Also would anybody with a tdv8 and a IID be willing to check the ecu voltage during cranking??

Cheers in advance Clickadeeclick

The starter came back from testing and is apparently all ok and passed the load test and current draw tests but they couldn't open it up to check inside due to corroded bolts, I am still tempted to replace it while it's out though as it's not
something I want to do twice. Clickadeeclick

If the car is starting perfectly from cold but not from warm, have you tried running tests on the coolant temp sensor and oil temp sensor?

I know the oil temp sensor can cause issues on the TDV6 (more with cold starting I think) and I know on different marques (ie VW) the CTS will cause an issue very similar to what you've described if faulty. MY08 RRS TDV6, Chawton/Black, sunroof, hk, 268k km
2001 Audi A4 1.8T quattro 5mt sport, 340k km
1990 Nissan Pintara TRX, lots of mods, 438k km

No I hadn't given them much thought tbh I will check them and report back, cheers for the input  Clickadeeclick

There's a strong possibility you may have a faulty crank position sensor, well known for causing hot start issues.
Edit to add, just read through more of your posts and can see you've already suspected the crank sensor. Doh. Must read threads properly before posting my previous car (V6 TDI Touareg) had the exact same issue which a new crank sensor solved, hence my hasty post

I was so convinced it was the CPS that had it no been such a bitch to do I would of replaced it in a heart beat I had even priced it from Dan @ Duckworths ready but alas it wasn't to be, the results from the scope were spot on, I have decided to replace the starter just because it's out not because I think it's the cause of the problem it's just peace of mind that I know it's done, I say it now I bet it's something so silly an obvious, I just wish there was more time to spend on it thanks for your input  Clickadeeclick

When checking the injectors leak off rate yesterday I noticed that the plastic return (leak off pipe) is carrying supply fuel from the low pressure pump in the tank when the ignition is on and engine is off which doesn't seem right to me I'm thinking that maybe the pipe work at the filter maybe wrong so I was wondering if anyone has any info on checking this or if somehow this is regarded as normal? Clickadeeclick

Finally sorted the hot starting issues, the starting ok on a booster was just a unexplained spoof, it had 4 injectors leaking off too much fuel which didn't affect the cylinder balancing or the cold start, quite frustrating as that was one of the top of list after the low pressure was sorted but I get led down the electrical route, damn that booster box lol.
At least it's all sorted now maybe I can start enjoying it now.
Thanks for all your help and advice Clickadeeclick