A fluid delivery device and system configured to regulate delivery of fluid through a fluid delivery port to a target site within a patient, such as to identify, locate, dilate, etc., an opening in a tissue wall at the target site. A side port is defined in the wall of the fluid delivery device adjacent to but upstream of the fluid delivery port. If the fluid delivery port is partially or fully obstructed by contacting tissue, the side port provides a relief valve reducing the pressure of fluid from the fluid delivery port impacting the contacted tissue. The fluid flow path upstream of and adjacent to the side port may be tapered to create a Venturi effect which may cause entrainment of excess fluid at the target site into the fluid delivery device. Such entrained fluid may be recycled out the fluid delivery port.