It appears my fuel cap isn't venting properly so after we had stopped for a break and with the scorching hot temperatures I had developed a vacuum in my fuel system. Not knowing all this at that time tho. Richard (blow-in) came back and was having a a we look suggested to open the fuel cap a very large whoosh As the pressure realeased and the car started every time after although I was opening the cap ever time we stopped. Once I had got home and the temperature cooled tried the cap again and it was fine no longer vacuuming. Think ill have a look at the vent today tho.