Range Rover l405 rough idle

hi guys
I’ve got a Range Rover 4.4sdv8 L405
I’ve had nothing but problems, can u please help.
It has been to a specialist who have said it’s a low pressure fuel fault, they replaced so many sensors and now it’s showing a high pressure fuel fault. I then took it to Land Rover who have said it sounds like a high pressure fuel pump and maybe injectors. I don’t want to be spending a fortune. It starts fine and runs ok when it’s cold, as soon as the temperature reaches half it’s got a rough idle. Also last couple of days when I press the ignition off button it has a 10 second delay to turn the engine off.
I have also noticed a strong fuel smell outside the car.

What exactly do the diagnostics say?
It might be injectors as they can cause rough idling but, basically , it's all guess work without codes.
I know on my L322 , I had the fuel smell, outside, when the fuel rail was 'flooded'. Sadly, can't remember the cause but someone here will know
You've picked the wrong vehicle if you don't want to be spending a fortune