I don't believe in throttle body actuator.
The throttle is operated by a computer following situations:
- In idle to control idle speed
- In cruise mode to control vehicle speed
If you have electronic accellerator and antislip, it will also control the throttle in normal driving mode instead of a mechanical link.
In any case the actuator will simply act as throttle control, whereas your problem more sounds like an ignition or mixture problem.
I once had similar symtoms, where it would run without problems for long time. But in certain temperature/humidity conditions it would stumble and stop being very hard to start again, and then driving perfectly alright for another period of time. That turned out to be the ignition coil.
But a manifold vacuum leak could also create your symptoms, so try first to look for any leaks.