This frame 5 unit is 40 years old or so. During attempted starts the unit lights off ok, but fails to get to 60% to break away. Fuel rate increases and exhaust temperature rises towards isothermal. We suspect the torque converter or diesel. We are checking diesel engine speed. for the torque converter there are a number of check valves in the feed from AC & DC pumps to prime the charge pump, and check valves in the tank for charge pump suction. these too are being checked. Does anyone have data on what pressure should be seen on the charge pump discharge while the diesel is operating at 2300rpm. This data will let us check that device. The torque converter has no 20TU fitted.