JT8D-9A slow to spool.
Need help trying to figure out why our JT8D-9A is slow to spool. It is taking about 9sec to spool up to 1.2EPR. Fuel Control(replaced), trim checks good, PRBC-Replace, P&D valve replaced and all bleed valves are opening and closing. All PS4,3 lines and moisture trap checks good. I am at a loss. Also, combustion chamber boroscoped and no problems noted. This is a duplicated gripe and it has followed with a new engine being installed. Any ideas?