Prior to the flight, the pilot preflighted the airplane and recalled observing the fuel gauge indicating full; however, he did not visually check the fuel tanks. The airplane departed and the en route portion of the flight was uneventful. During the downwind leg of the circling approach, the engines began to surge and the pilot added full power and turned on the fuel boost pumps which "seemed to resolve the problem..." While abeam the approach end of the runway on the downwind leg, the engines again started to surge and subsequently lost power. The pilot executed a forced landing and the airplane impacted terrain short of the runway. Examination of the airplane by Federal Aviation Administration inspectors revealed the fuselage was buckled in several areas, and the left wing was crushed and bent upward. The fuel tanks were intact and approximately one cup of fuel was drained from the single fuel sump. Fueling records indicated the airplane was fueled 3 days prior with 135 gallons of fuel or approximately 4 hours of operational time. Flight records indicated the airplane had flown approximately 4 hours since refueling when the engines lost power.