HELP: Sometimes he doesn’t start and sometimes he jerks…?!

Hi, as Newbi here in the forum I hope that someone can help me here. My Punto Cabiro Bj. ́95 88PS sometimes doesn’t start and squirts sporadically during the ride…sometimes the fault light for the injection goes on. What can that be?? and here the detailed version: I have the Punto for about half a year and I am quite satisfied. After 2 weeks I had to make the ADAC efforts because the fuel pump had acknowledged the service. With a new (used) n) then everything was OK again and he was driving… A few weeks ago the red light for “injection” went on during the ride… but it also went off again. Since that time again and again with more or less jerks paired. And since about 3 weeks he sometimes does not start, if you have stopped briefly and want to start the engine again after a few minutes (e.g. after refueling). If you wait then 5 minutes, he starts as if nothing had been done. However, it was now one morning that ic He then checked whether: – Zündfunke is there –> OK! – Signal for the injection nozzles is there –> OK! so he closed on the fuel pump…and with a few hammer strokes the box ran again. So I ordered a new fuel pump and today -after he didn’t jump on again and extremely jerked off when driving – the new pump was installed. But now he doesn’t start at all?! But I don’t really know which line he had to call again. nau for what is and which sensor does exactly what and which valves there might still be. Is there any hose diagrams and block diagrams?? Then I scraped off the fuel line, which goes to the distribution rail, which supplies the injection valves with fuel. There is fuel in it! I then let it run out and after a new (successless) start attempt was again fuel in it. seems to work…?! he me nem laptop over RS232 read out the error memory? I am very curious for your tips!! Thank you!!