kind of gravedigging, but for others that may run into this, if you are on P3D and still have the default vanilla traffic files being used, a couple of the planes included in the p3d base install are from Carenado/Alabeo, and when they built the models, they put in code to randomly shut player engines off if the plane was being used for ai traffic. I ran into this and just renamed the titles of the Commander 114 and the Extra, and never had the issue again.