M20 here too 1989 263,000

new injectors, new fuel pump and long cranking times exactly as you describe
my theory is moisture condensation inside the rotor cap which may be caused by bad gasket or a tiny crack, no spark no engine start;
this condensation can occur only when the engine warm and started to cool off just a little bit temperature gradient and there it goes; before and after this moment this moisture is gone...


have you ever replaced the idle control valve or AFM?