M103 starting issues

Hello! I replaced the head gasket on my w124 260E M103 from 1992. I made a lot of pictures during the process. Put everything back together as it was. The car only starts with a lot of brake cleaner. As soon as the brake cleaner is out the engine dies. In my oppion the engine does not get any fuel. But what could have gone wrong? I didn't disassemble the injection system, except removing one fuel hose. But the air must have been out after all the starting attemps, or not? I don't know what to do... feel kinda hopeless. Here's a video of the running and dying engine: