***Case 480F LL with Cummins 4b engine and Delphi pump. Hi everyone I’m new to this forum! So what I have is a machine that has sat several years. In the beginning it will start right up and then take for ever to throttle up and after about 2 qts of transmission fluid in the fuel it has gotten much better on throttle up but still not as responsive as it should be. And also it will die if the throttle is not slowly let off then sometimes restarts right up and sometimes cranks a bit and then starts. It has all new fuel and filter.
Welcome to HEF @Chipw If the machine has been sitting several years, it is possible that a hydraulic funtion lever is not fully returned to it's neutral position - this will cause the engine to be under hydraulic load. On a loader there aren't too many to check - loader lift, tilt, 4in1? Are the skip bin controls binding in any way?