On April 25, 2009, about 1040 Pacific daylight time, an experimental homebuilt Stanton Glastar, N518PV, nosed over during an off airport landing following a total loss of engine power near Redding, California. The pilot was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The private pilot was not injured; the airplane sustained substantial damage. The local personal flight departed Redding about 1000. Visual meteorological conditions prevailed, and no flight plan had been filed. The builder/pilot reported that during the flight the engine lost fuel pressure. He activated the second electric fuel pump, which corrected the problem, but only for a few seconds. The engine subsequently lost all power. The pilot initiated a forced landing to a dirt field where during the landing roll the airplane nosed over. It was determined by the personnel on scene that the airplane had more than 10 gallons of fuel on board. The builder/pilot reported that during the post-accident examination of the experimental 2.5L Subaru automotive conversion engine, he was unable to determine the exact cause of the loss of fuel pressure. The pilot opined that air somehow got into the suction side of the fuel system causing the non-self priming fuel pumps to stop supplying fuel to the engine.