Hi, got some problem with my 1993 1.3 toyota corolla carbureted engine. First of, the idle when set to 800rpm engines shakes, i replaced everything, plugs, wires, dist cap, fuel filter. I've already ask a mech to set timing to 10 btdc but still shaking so i opted to set to 1000RPM, it works ok, but after running engine for long drives, idle increases to 1100-1200 rpm. after setlling down for a while it goes back to 1000RPM, is this normal? with this setting, when i turn the lights on, idle goes from 1000 down to 700 and below and becomes erratic with the engine running really rough. what could be the problem? need some help. thanks.