As Ferdman mentions, there are many options to choose from.

However, I just remembered that I initially thought I fixed my problem by pulling the Idle Air Control Valve and cleaning it out. Did make a huge difference, but I still have the missing start with rumbling idle. Since I became aware of the issue with fuel boiling in the fuel-line when the engine is shut off, the error observations make more sense. I find it typical that starting in warm wheater or after driving a while is bad. So starting the car for a short while at night, it will fire right up next morning, but driving it home from work and leaving it untill next morning will make it tumble. So I have bought the theory on the boiling fuel and will replace the two contra valves on top of the fuel pumps.

Oh yes, I did try replacing all the ignition components (coils, HT-cable etc. )
and while it may have been due, it did not help my starting.

Regards