Engine Troubles
Not an Aston Martin problem but food for thought.
My company in the garage most weekends is Robert. He’s supposed to be restoring a Rochdale Olympic (strange glassfibre monocoque car from the early 1960s) but more often gets distracted by his Davrian (strange glassfibre monocoque car from the late 1960s).

Robert’s Davrian has engine trouble. The problems started off with a head gasket failure, due (we think) to crazy cooling pipe routing which didn’t allow the cooling system to be blead. A lot of modifications followed and the car now has a problem with cold starting.
Robert spent several weekends investigating and replacing all the obvious things, but still the problem presisted.
Finally we’ve twigged. “How long has the car been standing here?” The petrol in the car was bought in September when it was lovely and hot. But petrol companies change the petrol grade through the year as it gets colder, and winter fuels are much more volatile than summer fuels. Add that to the petrol being stale (the useful hydrocarbons having evaporated) and we have our answer.
A new tank of fuel and the car now starts.