On July 27, 1996, at 1728 hours Pacific daylight time, an amateur built Thompson Long EZ TR airplane, N42DJ, nosed over during a forced landing after takeoff from the Yucca Valley, California, airport. The forced landing was precipitated by a loss of engine power during the initial climb. The aircraft was owned and operated by the pilot and was beginning a personal flight to Palm Springs, California. Visual meteorological conditions prevailed at the time and no flight plan was filed for the operation. The aircraft incurred substantial damage, and the certificated private pilot, the sole occupant, was not injured. The pilot reported that the aircraft was about 300 feet agl in the takeoff initial climb when the engine suddenly quit, restarted momentarily, then quit altogether. The pilot attempted to restart the engine but had insufficient altitude and he landed in soft desert terrain. The aircraft nosed over during the landing roll. An FAA airworthiness inspector examined the aircraft. He reported that the left fuel tank was selected, and that tank contained about 3 gallons of fuel. The right tank contained 5 gallons. No mechanical discrepancies were identified with the engine during the examination. The pilot is an airframe and powerplant mechanic and reported that his aircraft is equipped with both engine driven and electric fuel pumps which are plumbed in series. He stated that following recovery of the aircraft he performed functional tests on the fuel system. With the electric fuel pump turned on very little fuel would flow from the pump outlet line. When the electric pump was removed from the lines, the flow rate to the gascolator was measured at 12 gallons per hour.