Combines 8820 fuel bleed down problem

The electric transfer pump, hand primer check valves, or the filter check valve could all be the culprit. There might also be a check on the fuel return line on the injection pump. Most likely the check valve on the filter base.

I don't know what year your 8820 is but some of the earier ones had a steel fuel line. They would get a hairline crack that was impossible to see but cause all sorts of starting problems. Ihope that helps.

Thanks for all the info. I will inspect the fuel

The line goes from the frame to the fuel pump. If it is steel get a steel braided hose. There is a change up to this thru JD. I hope this works.