Difficult cold start
Thanks slantsixdan.
I have tested carburetor and it makes strong shot of gas even after a week so I think there is enough fuel in bowl.
There is also thick gasket between carb and intake. But I think heat control valve is stuck, I haven't have time to check it yet, as I thought that it dose not affect this problem.
I have also checked choke. But it starts better without it (warm climates now), so I have disabled it temporarily now.
With choke on, car might not start at all, I assume that it gets too much fuel and wets spark plugs.
With choke, it does not even promise to start. If I pump pedal, it looks that it wets spark plugs.
Without choke, it starts "promising" to start when I pump pedal, but it still takes long time cranking and pumping until engine stays running after I release starting.
I try to take video next time.
Why I want to add relays to coil circuit is that my opinion is that under 10v when cranking is too little. I think that volts are lost in ignition switch circuit and wires so wiring relay direct from battery would help voltage not dropping so much. I am electronics engineer so electrical circuits are not problem.
This thread is also my checklist for things I need to do next winter.