Case 1840- starts sometimes- usually not. If it starts it will run all day at full throttle- no hesitation etc. Cranks fast when trying to start. Is there a solenoid that is easy to find or tap etc. When it does start and you shut off- no guarantee it will start anymore than a cold try.
Ray, our SF Engineman will be contacting you directly about your question. He said his response would likely be many pages and he would like to dialog back and forth with you about it in order to answer your question effectively.
It could be the injectors not putting out a fine mist to start, but it`s good enough to keep it going once started. Or the pump, pieces of a seal floating around in there that settle in places that make restarting tough. Just some guesses.