[RustyLugNut]

Use ethanol rated solenoid fuel injectors. They work well for water injectors. Use a water pump that is rated at 80 psi and pressurize a working chamber that has an elastic buffer (spring or gas). Use a basic Arduino to deliver your needed flow between 55-80 psi through a hexfet with a capacitor bridge using pulse width modulation. Easy peasy. The pump does not need to run continuously and the Arduino can be programmed to cut in the pump below 55 psi to replenish your reservoir.