I complained of this with my 2000 Sport under warranty. The dealer said," Don't turn the the pump on and off briefly without running the bike. Don't run the motor briefly like just to listen to the pipes, The remaining pressure in the lines will give the leak."
Guzzi then, under warranty, replaced the entire injection rack ( throttle bodies , injectors, TPS and linkage ). The motor had to be loosed from the frame to do this. What a project! The RH TB still dripped after( maybe not quite as bad). I give Guzzi credit for trying all they could do to make it right.
Now I am careful not to * briefly * run the motor as this appears to increase the drip.