I can't figure this one out. Car has done 110k. Cold starts in the morning are no problem. Drive the car up to temperature. Do a short stop off, such as a shopping trip - about 20-30 minutes, car will start, but almost fails to 'catch' and splutters on startup. Drive is perfect. Drive the car up to temp, for a long journey, stop engine for a longer period (hour or more, or until next morning) and car will start perfectly. Only seems to be warm starts. On one occasion it 'caught' and then cut out. Fired right back up after that. High pressure pump is brand new, as it was lazy starting on cold mornings which cured it.