I also have this problem.

I have spark to the plugs, lay them on the head.
I have fuel pressure in the fuel rod.
Replaced spark plugs, air filter, distributor cap, spark plug leads.

I am assuming that because I have spark the cam position sensor is working.

The engine spins under starter motor ...

I have the same connector and I wondered what it was. I think it's for powering headlight wipers.

Just a guess of course