My daughter has a 1985 (according to the door sticker) 240DL station wagon. It has been stalling at stop lights and at low RPMs. It fires up sometimes for 30 seconds or so and dies. When you get it up to speed and give it too much gas it makes some sort of sucking sound and loses power. I've replaced the in tank fuel pump, the in line fuel pump, the fuel pressure regulator, and checked everything on the fuel lines. I am at a complete loss!! Does anyone know what may be the issue? I also cannot see a visible flame trap, which I was told needed to be cleaned. Any help would be greatly appreciated.