Problems with cold start?

Hello everyone,

My Mercedes 190 w201 (90 hp petrol) from 83 has been having cold start problems for some time.

If the car is parked overnight and I start the engine (the starter works perfectly), it starts for two or three seconds and runs perfectly. Then the revs drop and the engine starts to jerk. If I give it some gas right from the start, it stays running and runs smoothly.

Sometimes when I start driving and give it a lot of gas the power goes away and it jerks again and threatens to die until I take my foot off the gas.

If I start it at lunchtime after work there are no problems at all.

It's especially bad when I don't drive it at all over the weekend.

At the moment I just let it warm up for a while without driving and then everything goes relatively well.

However, I would really like to fix the problem. Does anyone have any ideas what I could try? I recently replaced the spark plugs because I thought that might be the cause. The engine and transmission oil have also been recently changed.

Best regards