Massey 1105 fuel problems

Ive been having problems with my 1105. Twice Ive ran it low on fuel and had this problem but this time its not working. The tractor would lose power but stay running then it would boost back up where it should be. Then sometimes it would die, the only way to get it started again was with either. We changed the fuel filters and pick up pump. Once we got it running again it ran fine until yesterday. I ran it low on fuel and it started giving me problems I filled it back up with fuel tried bleeding the system and no change, except instead of staying running it would die. I would start it again with either run it for a few minutes and it would sound great then I would take off and it would lose power then die. Today I changed the filters, bleed the system again and now it will start with either run for a min. and die. Im dont know if its the injection pump dirty and will need rebuilt or the injectors. When I crack the lines at injectors the tractor loses a small amount of power and fuel its spraying out, I tighten it and it powers back up. So everything fuel wise seems ok but I dont know. I just need this thing to run long enough to get me to spring time then its going to auction. Its been nothing but trouble. Ive replaced all the hydraulic pumps to get good pressure to my attachments and so I have some steering which still sucks and the steering pump whines like crazy but its a new pump and all pressures should be set right. Any help would be great.

Remove the fuel pump outlet line, work the hand prime lever to see if there is good air free flow. May need to turn engine over slightly if cam lobe is holding lever up. Should be a good shot of fuel with each stroke, have seen supply pumps with loose check valves, which upsets flow. Also check the constant fuel bleed orifice on top of filter base, has a line to injector return. When it plugs air that should go through goes to injection pump instead, causing it to shutdown as pump can't handle air in fuel.

Thanks for the advice. I found the problem lastnight. I didnt have a good flow of fuel from the tank to the pick up pump. I took the line off from pick up pump on the tank side blew some air in the line, I waited awhile to let the trash settle then it fired up with no problems. Now if I could just get the steering working like my case I would fall back in love with my Massey.