As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 2 ENGINE WAS VERY SLOW TO SPOOL UP TO 40 PERCENT N1. ACFT GROUNDED. PERFORMED ENGINE ACCEL TEST, 3 TIMES FAILED, EACH TIME WITH ACCEL TIMES OF 11.6,11.4 & 11.2 SECONDS IAW MM 71-00-00-700-824-F00. REPLACED NR 2 ENGINE HMU IAW N8473000 AND N8473001. PERFORMED TEST ACCELERATION CHECK AND NR 2 ENGINE OPS CHECKED GOOD. ACFT GOOD FOR CONTINUED SERVICE.