Just change my Autronic SM4 to Vipec V44. The idling is so much better now! Actually, I fried my SM4 thus bo pian have to change ECU. Didn't know that my SM4 is actually giving me idling problem on my car, the car will vibrate alot but now with the vipec its much smoother, I no longer see my bonnet vibrating.
Was told that Vipec controls the idling much better than SM4 and has a much more powerful CPU as well (SM4 uses an old Intel 20MHz 16bit ECU, I suspect its 8086.... ancient)