An ink delivery system for an inkjet printer includes: a positive ink line; a negative ink line; and one or more print modules interconnected between the positive ink line and the negative ink line. Each print module includes: an inlet port; an outlet port; a printhead interconnected between the inlet port and the outlet port; a control valve positioned at the inlet port for controlling an ink pressure in the printhead; an ink pressure sensor for sensing an ink pressure in the print module; and a controller for receiving feedback from the pressure sensor and controlling the control valve. During printing, the ink pressure sensor, the controller and the control valve cooperate to control a backpressure in the printhead within a predetermined backpressure range.