You CAN be 2 rich

I had my fuel flow reset to spec recently and have noticed that I am no longer able to hold 10-12in of mp with anything close to a full rich setting. The engine sounds like it is drowning in fuel. .When I turn final, I must lean aggressively to keep a smooth turning prop. I also can not hit the boost pump as called for in the chk list as this will give the same result. I had it checked again today and the Mech said it was on the numbers…any suggestions would be appreciated…thanks