Hi, My focus has developed a problem where upon starting the car runs for a few seconds then cuts out stating 'engine system fault' and will not restart. RAC plugged in and seems the fuel pressure was too high with error code referencing the fuel pressure sensor. Having reset / cleared the errors the car re-started and after a short time pressure went to normal. RAC suggested a bit of dirt as seemed to sort its self. The issue has occured again but my local garage are not confident of what the issue is. Once running the car runs faultlessly with no issues. I do most of the maintenance myself but never had to get involved in the computer of fuel system side! As there are no symptoms when the car is running could the issue be the pressure sensor on the rail, mass air sensor... cant see it being the pump if the pressure is too high or the filter as surely if there was resistance their I would have hesitation/loss of power under high rev?

Suggestions greatfully received!