A vane-type camshaft phaser for varying the timing of combustion valves including a first torsional bias spring disposed on a cover plate spring guide and grounded to the cover plate and to a slot in a spring retainer to urge the rotor toward an intermediate locking position from any position retarded of the locking position. A second torsional bias spring also anchored to the cover plate and spring retainer urges the rotor in the advance direction over the full range of phaser authority to compensate for added camshaft torque loads imposed by non-valve actuating functions such as driving a mechanical fuel pump.