Engine goes off

Hello first of all, I really hope that someone here might have a tip for me. Drive a Fiat Seicento Sporting from 1999. On the way to work my little one went out 5 times today. Each time I had to stop or if the speed was relatively low. 4 of the 5 times he then jumped perfectly again at the last time but it didn’t work at first and after a minute I tried again and then it just went with a lot of gas. Before the engine started to get around I already had a distance of about 25 km almost all the highway behind me (so the engine was definitely not cold anymore). For the way home I had already set myself up for the worst, but oh miracle he stayed nice on. What can that be, about 4 weeks ago this happened to me already and afterwards he ran like a lukewarm again. Does anyone have an idea or a good advice? Thanks already.