I was experiencing the same issue with my M7060HD with 210 hours.
Engine would die like the key was turned off. After a few minutes with the
ignition on, it would start and run for 15-20 seconds and die again. Frustrating.
I spoke with the technician at our local dealer and he pointed me to the
fuel shutoff solenoid. This wasn't the problem. I also noticed the water separator
was slow to fill or would not fill completely. I removed the fuel line at the separator
from the tank and found it was completely blocked with grass and debris, severely restricting
fuel flow to the separator. Remove the separator, removed the stop cock stem and cleaned
out the debris from the entry to the fuel separator. Instantly cured the problem of no
fuel getting to the injectors. We purchased the tractor from a rental fleet with 105 hours,
so I presume the former user(s) left the fuel cap off while cutting with a disc cutter.