Most of the time, it's because people don't trust each other that your helping become your death, or no one saves you even though you can be saved. At least when I played with people I know of their capability, I can feel the trust between us that I will turn around and fight with my sliver of health. So when I'm playing solo, building trust is the first thing I must do
. Let them know what you can do, what you will do, and which signal (like if I ping 3 times, it mean I, as Pantheon, will jump there). It's not that bad when people anticipate what you are going to do.
Btw, which timezone are you guy at? I hardly see anyone in LoL (well, I haven't had time to play much these days either
).