Sounds to me like you have no vacuum applied to the FPR.
59 is reasonable from a stock fuel system with a walbro at WOT but at idle it should be pulled off to around 45psi, maybe 49psi with your numbers. That is what the pcm is expecting, an automatic enrichment when you hit the gas. The boost will make it rise a little bit but not significantly.
I had mine hooked up to vacuum/boost and I was always able to dial in my AFR pretty easily.
Nice round torque curve you got there.
What boost level?
