Good fuel - really don't know, but that has not changed, tank is 1/2 full or so - so was running on that fuel for at least 100 - 150 miles.
As for the cold start valve - not really sure. But when removing the spark plugs there is fuel smell (and injectors spray) - so no fuel is not the issue. If it wasa hard to start - then maybe.

I am wondering about three things (and I am sure there are others)
1) can somehow the timing be so far off that the engine won't start - and how could I verify on this car that the timing is off or not?

2) qaulity of spark - how does one identify a weak coil - where you get a sprak, but it is not hot enough. The coil resistances measures as per spec (with a multimeter). How else can I determine a weak coil?

3) Is it possible that the catalytic converter is clogged - how would one determine that?

Klaus