1994 Renault 1.1 monopoint startup problem

My old car is giving me headaches again. This is what happens, especially around the damp, rainy days.

Crank the car, it immediately starts, cranks right away without any hesitation…idles normally, calmly…and after 10-20 seconds, it turns off, just dies.

Then I try to crank it again, and I have to turn and turn and turn the engine over until it starts giving some signs of possible ignition…then you hear the 2 cylinders catching on and finally after 20 seconds of cranking, the engine starts but this time the idle is shitty, and if I press the throttle it just kills the engine.

Cranking it again, turning it over for 10 seconds, the car starts and I can gradually give it throttle, if it starts to give the signs of shutting off I press the throttle and rev the engine and it finally starts to idle normally and drive normally.

Where do I look for problems? I know this is a hefty question when dealing with 20 year old rag but still…I’m in that kind of situation right now. I want to fix this because few days ago I had this scenario on the road, not on my parking lot where I can stall the car whenever I want. I cranked the car, it started normally, I drove uphill to the first stoplight and the car was idling at the stoplight and then just died. I somehow managed to get it running just when the green light came on but this is not something I want to experience in city traffic again.

Thanks for any suggestions