Skoda Felicia 1995 monomotronic,revs rising and falling at idle

 I have a 1995 Skoda Felicia 1.3 mono-motronic  and I have  trouble, the engine starts fine and then runs alright , after car warmed up it start revving high at idle for minites, also the same situation when driving at first gear at very slow speed, and engine needs to stop and smile more gasoline  however,  if engine stopped it difficult to start again  .

I changed the upper  injection unit complete  (including throttle, TPS sensor ,injector, , idle motor , ...etc ) and still problem not solved .

Any help or thoughts much appreciated

thanks,