In contrast to the Continental system, the Lycoming (Precision Airmotive, a.k.a. Bendix) system only needs enough pressure to supply the fuel - the pressure level has no influence on the fuel flow rate.  The system needs something over 11 psi to operate, and 15 is more than enough.  There is usually no reason to turn on the electric pump unless fuel flow is interrupted.  I think your system is behaving normally.