I Have a 1990 Subaru Loyale Wagon and when i start it up it runs fine but after a while it starts to idle really low like 500 and below. i was having a problem with it over heating down the highway and had to limp it home by driving then letting it cool off. i found out it was the thermostat, it was all magled and messed up. so i just took it out. my car runs colder but it doesnt over heat. so does anyone know what might cause it to idle low. i was thinking timing or something like that but im not sure.