Longgg crankinggg 400E BUT THEN?

[88260e]

So my 92 400E cranks "I think" a long time before it starts hot or cold! Every time its Rer-Rer-Rer-Rer-Vroom, the other day it was -2 here and it would not start in the morning, cranked strong but would not turn over! So after 4 or 5 tries I gave up. But when I came home from work with a can of starting fluid to try it again. I said let me try it once before I spray it with the starting fluid! So I jump in crank it and I get an instant VROOOM fired up instantly. WTF 14 degrees sat all day and fired right up??? I'm confused, new Battery plugs,caps,rotors,coils,fuel pressure reg and fuel filter,and new engine harness! Why would it fire right up after not starting in the morning.