my car's rpm will drop from normal 900 to 500-600 when driving in the hot weather, especially noon time. and d car performs damn sucks at that time! bt during early in the morning o at nite, d car is ok, i mean d rpm idles stable all d time. anyone driving 4g91 facing d same problem? another thing, i dunno other 4g91 engines, but my engine, when i'm cruising, no matter in highway o street, d rpm will suddenly drop a bit, for like 2 sec, den goes bec to normal. is tat normal 4 a 4g91? pls pls......need help here!!