Tipan

Hello,Dears we have installed  a GTC(85-71A) on C 130B aircraft having T56- 7B engine. After installation,GTC started normal &produces 34 psi press with 4100 ft elevation & 26 °C temp in the air field.But during main engine start GTC press drops to 15 psi,gain slowly up to 22 psi before starter release.The main engine takes time to become on speed 75 sec which is out of limit. For rectification already we have changed GTC load control valve,two thermostat, acceleration limiter, speed switch, FCU,air press regulator but found no joy. In this situation i seek your valuable opinion to rectify the GTC,so that main engine could be started with in 60 sec approx.