560sel won't start unless I pull the fuel pump relay?

[nestomicon]

Hi, I've been tracking down various problems with the fuel system and I think it's almost figured out. I replaced the fuel distributor with a spare and am getting pressure to it, and the piston is not stuck. Everything seems to be normal, and I adjusted the mixture screw so it should at least start. When I try to start it, it runs very rough on maybe 4 cylinders or won't start at all, but if I pull the fuel pump relay out it will start and run perfectly for a few seconds.. Could this be a fpr issue? I don't know what else to check, any help is greatly appreciated.