Update for this problem
Problem : RPM auto rev 800-1200 unlimited times until off
temperature.
Day 1 (01062019) - I went to one of the aircond workshop. The boss uncle say it might be my valve or throttle body dirty, so he remove it and wash it, then wash the front radiator as well, total charged me rm8x. But after I reach home,
if i use aircond the engine also rev up down again,
if i no use aircond the engine RPM go down to 300-500 the car keep shaking, like manual car no press clutch

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Day 2 (02062019) - Before I go to workshop again, early the morning I start the car, the car keep RPM at 500 and no cold start feeling means no high RPM while I doing cold start.
if i use aircond the engine RPM no go up and no aircond means the compressor stop function because RPM too low, until I press pedal, the aircond comes immediately but once I stop at traffic light then RPM low again and aircond automatically shut off.
I went there and ask him again, then he say maybe the RPM set too low, let him adjust abit, so after adjust, without ON the aircond, the engine keep at 2000 rpms, when ON aircond it will magic drop until 1000 rpms, after half day, the auto rev problem not occur again but the RPM will suddenly keep at 2000 rpms.
I dont want to adjust the RPM to forever 2000rpm, it is ridiculous, he say put higher in order to dont shut off the compressor. But how come all the while no this issue. Only happen after he do something on the engine part on the day 1.
idle in 2000rpm is too much even with compressor kick in, the factory idle rpm for avanza is 750rpm, u can see this inside yr hood. normally if compressor kick in, it will rise to about 1000rpm, in early morning cold start engine is about 1.5k rpm, after engine heatup, it will drop to 750rpm. i suggest u adjust back to 750rpm, sry but i cant help much on the aircond issue though, have u chg the compressor as well?