Record E1 Injection problem

Dear Opel municipality, I’ve got a fire-fighting guide vehicle record E1 Caravan 2.0E with automatic. The vehicle stood there for about 2 years still. A jump was very heavy, but the engine runs great and has a really good performance with its 110 hp. The record still has the L-Jetronic and is original from Jan. 1981. 50tkm. When the car stands 1 day, it starts just as hard as originally after 2 years. I made the AU today and he had a CO value of 0.28 Super like I mean, without a cat! Why does he always start well, except after more than 24 hours? Does anyone know advice?