The experimental, amateur-built airplane was in the Phase 1 flight test phase and had accumulated about 4 hours flight time when the accident occurred. The pilot reported that he had noticed low fuel pressure during the accident flight. He activated the fuel boost pump, which returned the fuel pressure to within normal limits. As the airplane approached the intended destination airport, the pilot smelled smoke and observed a fire in front of his right foot. He discharged a fire extinguisher, which put out the fire; however, the cabin filled with smoke. He closed the fuel valve and opened the pilot's side door. The door separated and some of the smoke dissipated. The pilot observed a pasture off to the left through the open door. He subsequently landed on an uphill slope, causing substantial damage to the fuselage and right wing. A postaccident examination of the engine revealed a loose fuel line fitting at the mechanical fuel pump. The fire occurred along the lower fuselage skin in the center console area, which ran forward to aft between the pilot and copilot seats. The lower fuselage skin was burned through as a result of the in-flight fire.