I have been trying to figure out why I'm having such a hard time tuning the engine. The other day we ran the plane on the long taxiway and it did not sound stable. We had occasional pops and the mixture kept going too rich or too lean.
Today I was thinking if it has something to do with the fuel pressure regulator being controlled by the manifold pressure. As the MP varies, the FPR changes the fuel pressure. So the computer is trying to compensate the injector output for manifold pressure, but the fuel pressure is changing at the same time. I have seen the FP changing from 35 psi at low RPM to 50 psi at high boost?
I wander if I should set the FPR at one value and let the EC2 take care of the rest?

Buly
Resealing the oil pan/engine mount to cure oil leak
Welding a tiny leak in the radiator