Vito 110 cdi 2002 - hard to start when hot
 

Hi,
I am an Englishman living in Spain. I own a Vito 110 cdi, 9 seater, year 2002.
She is okay starting cold but as she gets hotter she struggles to start.
I usually have her serviced by Mercedes, Almeria but due to finances I wish to sort this problem out myself.
Any help very much appreciated.
Thanks in advance,
Paul