THE PLT RPRTD THAT DRG TAKEOFF, THE RGT ENG LOST PWR AS THE ACFT WAS CLIMBING THRU APRX 50' AGL. HE ELECTED TO SHUT DOWNBOTH ENGS & ABORT THE TAKEOFF BY LANDING WITH THE GEAR RETRACTED. THE ACFT SKIDDED OFF THE RGT SIDE OF THE RWY. AN EXAM OF THE RGT ENG REVEALED HVY SOOTING OF THE SPARK PLUGS & EXHAUST SYS. WHEN THE RGT ENG WAS RESTARTED AFTER THE ACDNT, IT INITIALLY RAN ROUGH, APPEARED TO HAVE A RICH MIXTURE & BLACK SMOKE CAME FROM THE EXHAUST. EVIDENCE OF EXCESSIVE FUEL PRESSURE WAS NOTED. THE FUEL INJECTOR PUMP WAS CHANGED, THEN THE ENG RAN NORMALLY. AN INSPN OF THE PUMP REVEALED THE LOW PRESSURE ADJUSTMENT BOLT COULD BE ROTATED WITH FINGERS. DISASSEMBLY OF THE PUMP DISCLOSED THE INTERNAL LOCK NUT WAS WORN & UNSERVICEABLE. MAINT RECORDS SHOWED THAT ENG PROBLEMS HAD BEEN RPRTD ON PREVIOUS FLTS. ON 6/21/89, THE (RIGHT ENG) TURBOCONTROLLER & FUEL PUMP WERE ADJUSTED FOR BOTH HIGH & LOW PRESSURES. PROCEDURES AT THE MAINT FACILITY FOR TURBOCHARGED ENGS WERE NOT IAW TELEDYNE CONTINENTAL SVC BULLETIN M89-10.