Hi Deanyel
When I pulled the line out of the fuel pressure regulator the engine was cold (after a frosty night).
Now, what do you think of this?
When I went back to the garage to pay the bill the boss told me he had been thinking of my problem. He said there was another possibility to explain the symptoms.
He said my engine had some difficulty with the oil reaching the top of the engine. That could lead to the hydraulic valve lifters being starved of oil. As a result, the valves could not open properly to the point of the engine being unable to fire up. At the same time, as fuel would still be injected in the manifold, once the valves resumed normal function a significant excess of fuel would get in the combustion chambers causing them to flood. He thinks this could be serious enough to render the ignition system unable to ignite this over rich mixture, hence the strong smell of unburnt petrol.
According to him, this could explain why the problem occurs first thing in the morning but never throughout the rest of the day even if it was cold and the car was not in use for hours. This could also explain why it does not correlate well with outside temperatures.