Neutral to Drive -- bad idling
When i put my automatic transmission from Neutral to drive, the rpm of my car drop alot to maybe 100- 250 to 700-800 in a matter of second. This happens to my car for some years now and recently my car stalled on a red light. Restarting wasn`t an issu, just turned the key a second and the car was idling..normally...
This happen only when i start the car and drive right away, when i let the car get warm for some minutes, this never happens.
The reason why i put it to neutral when i come to a stop is because my engine mounts, which are new, seems to be really stiff because in my car, it has a little vibration which because worst whenever it`s cold out. When it's getting hot, i feel just a little vibration which i considered normal for a 4 cyl.
That vibration on drive on a stop sign might be link with my issu discribed earlier.
What could cause this situation ? Idle air control valve comes in mind...what do you think ?