WRONG RWY APCH LNDG.

Narrative

I HAD JUST DEPARTED ON A MAINT TEST FLT AFTER INSTALLATION OF A NEW FUEL CTL UNIT. I HAD REMAINED IN THE ATA AND DURING AN NTS CHK THE ENG WITH THE NEW FUEL UNIT WAS PRODUCING APPROX 250 POUNDS MORE HORSEPWR IN THE LNDG CONFIGN THAN THE OTHER ENG; CALLING FOR A GREAT DEAL OF DIFFERENTIAL PWR TO MAINTAIN DIRECTIONAL CTL. THE TWR CTLR HAD INSTRUCTED ME TO FOLLOW ACFT Y ON L DOWNWIND FOR RWY 11. AT THIS TIME; I WAS LOCATED ABOUT MID-DOWNWIND FOR RWY 29. THE OTHER ACFT LANDED AND CLRED THE RWY. I HEARD HIM TALKING WITH THE TWR; WHEN I TURNED APPROX A 4 MI FINAL FOR RWY 29 AND COMPLETED THE APCH AND LNDG UNEVENTFULLY. AS I WAS TAXIING TO THE RAMP; THE TWR REQUESTED I CALL THEM ON THE TELEPHONE. UPON SPEAKING TO THE TWR OPERATOR; I REALIZED I HAD LANDED OPPOSITE THE INSTRUCTIONS GIVEN. THERE WERE NO OTHER ACFT IN THE AREA AT THE TIME OTHER THAN THE OTHER ACFT Y. I FEEL THE FACTORS RELATING TO THIS INCIDENT WERE THE FUEL UNIT PROBLEM; ALSO THE FACT THAT ALMOST ALL ARRS I HAVE CONDUCTED AT PORTLAND HAVE BEEN ON RWY 29; I WAS IN A HURRY TO HAVE THE FUEL UNIT PROBLEM CORRECTED SO THE ACFT COULD BE RETURNED TO SVC; AND WX AT MY DEST AFTER MAINT WAS DETERIORATING. I ALLOWED MY ATTN TO FOCUS ON THE MAINT PROBLEM IN CTLING THE ACFT TO THE EXTENT THAT I FAILED TO PAY ENOUGH ATTN TO THE LNDG RWY INSTRUCTIONS.