B757-200 RIGHT ENG FAILED TO RESPOND TO THROTTLE MOVEMENT DURING CLIMB. FLT CREW DECLARED AN EMER AND DIVERTED.

Narrative

WE HAD DSNDED THE ACFT FROM FL370 TO FL310 BECAUSE OF TURB. THE RIDE HAD IMPROVED AT HIGHER ALTS; SO WE WERE CLBING BACK UP TO FL370. FO WAS FLYING. I NOTICED; SHORTLY AFTER WE BEGAN TO CLB; THAT THE ACFT WAS NOT CLBING AT ITS NORMAL RATE; ONLY ATTAINING ABOUT 500 FPM. AT THAT POINT THE FO POINTED OUT THAT THE R ENG EPR WAS NOT ANYWHERE NEAR EQUAL TO THE L ENG'S NORMAL CLB PWR; ONLY POWERING UP TO ABOUT 1.4 EPR. THE 2 THROTTLES WERE TOGETHER ON THE QUADRANT; AT A NORMAL CLB POS. WE ADVANCED THE R THROTTLE TO THE FORWARD STOP; AND THE R ENG EPR DID NOT ADVANCE WITH IT; AND OTHER ENG INDICATIONS ON THE R ENG WERE ALSO NOT EQUAL TO THE L ENG. IT WAS OBVIOUS THAT THE R ENG WAS NOT DEVELOPING PWR. I FOUND LITTLE GUIDANCE IN THE QRH; AND PREPARED FOR A SINGLE ENG LNDG. WE NOTIFIED ATC THAT WE WOULD BE DIVERTING TO ZZZ1; DECLARED AN EMER; AND ASKED FOR THE ARFF EQUIP TO STAND BY. I DID NOT SHUT THE ENG DOWN; IT WAS OPERATING NORMALLY AT LOW PWR SETTINGS. WE DID PREPARE FOR A SINGLE ENG LNDG AND GAR; HOWEVER; JUST IN CASE THE ENG QUIT ENTIRELY OR WE WERE REQUIRED TO GO AROUND WITH LITTLE PWR FROM THE R ENG. WE DID A NORMAL 2 ENG LNDG; WITHOUT INCIDENT. FO WAS A GREAT ASSET IN THIS INCIDENT; WAS FOCUSED AND DID A GREAT JOB OF FLYING THE ACFT.