Non starting disco 300tdi

Hi guys this is my first post so be gentle,my problem is in the morning my disco starts first time I can go for a drive but if i
stop the disco and leave it for a short while it won't start again the motor spins over but that's all I had my mechanic look at it and he changed the fuel solenoid but after I picked it it fired first time drove it home stopped it and it won't start again my mechanic is a general mechanic and not a specialist Land Rover mechanic as these a hard to find in rural Spain so any help would be appreciated
Izzy

which year is the motor though?, is it EDC auto? cos it seems like a crankshaft sensor issue, these used to make tricks when they get hot then when they cool down will work again

My 97 manual had this, it would start cold but not hot. I eventually traced it to the black box covering the fuel stop solenoid which was breaking down(part of the immobiliser). The hotter the weather, the worse it was. If you have 3 wires going to to fuel cut off, it could be this.

Thanks for the information I will give this a go

Having investigated the engine it does not have an Edc,where is the fuel stop solenoid? Is it on top of the diaphragm that you alter for the fuel mixture

Search for discovery 300TDI fuel stop solenoid on t'internet. There is a video by Land Rover Tool Box videos showing the solenoid. It also shows the single wire. If yours has this, try running a wire from this to the battery and try and start it. Does your glow plug light come on and then go out?
Fozzie.

Thanks for the reply if I am looking in the right place mine has three wires and the glow plug light comes on and after a few seconds goes out . if as a previous reply suggests it is the black box with the three wires that needs replacing where do I buy it and how much does it cost??

I've just read your original post properly, I missed the bit where your mechanic had changed the fuel stop solenoid. The black box I'm talking about is a security device that completely covers the fuel stop solenoid on the injector pump, so presumably yours cannot have this if the solenoid has been replaced (it's designed to be a nightmare to remove it!)