If the casa is too expensive for you. You can try Delta Motors. There's 1 near Cubao, 1 in Marikina, as far as I know. They specialize in Toyota cars but significantly cheaper than Toyota casa itself.

I had my idling fixed there too. My problem was only a clogged throttle body and the whole thing was solved by cleaning. I don't know exactly what's the problem with yours but I'm pretty sure the mechanics there can provide you with a remedy.