Richard Salisbury

For the last 5 months after a long journey of at least 100 miles I have has great difficulty starting. It's intermittent - sometimes starts first time, at other times it won't start at all but mostly it starts after about 10 minutes of trying. Once it goes it runs perfectly. It will also start again if only left for half and hour or so, but any longer than that it won't start. The strange thing is that it gets over it after about a week of the long run and is then perfectly OK. My local village mechanic in Norfolk has checked the battery, the fuel filter, the heaters, the fuel pump and can't find anything wrong, but believes me that there is a problem. They took it to the Ford main dealer who I don't think believed the story and said there was nothing wrong with it. Long journey last weekend, same problem. This is getting beyond a joke. Anybody out there who can suggest what might be wrong so I can point them in the right direction?