I have an RV-9, 0320 D2A. Fuel pressure on start up is normal (4.5 psi) but goes to zero after 10-15 min of operation. Fuel flow indications are at normally expected levels. Fuel system is an inline boost pump, gascalator, fuel flow sensor, then to engine driven pump to carb. Pressure sensor is at engine driven pump discharge. I have changed fuel sensors to no avail. Do I have a small air leak or is vapor lock the problem due to excessive suction at the boost pump? Engine runs normally at all power settings including full. Any ideas welcome as this is very frustrating!
Doug Dahl N959RV
Doug Dahl N959RV