It might be worth downloading the data from the Fadec and e-mailing it to Sara. They are pretty good at diagnosing problems from this data.

If you have fluctuating RPM readings when the engine is stationary then this can be caused by servo interference. You can get a lead to go in the RPM line that stops it. It is not a problem as the sensor signal when the engine is running is much stronger than the interfering servo. I have it on my L39 due to the close proximity of the elevator servo but it does not cause any problems with engine running.