Look at this link.
http://www.peachparts.com/Wikka/OM606DeliveryValveSeals it's pretty much the same as this:
http://www.peachparts.com/Wikka/OM602InjPumpFuelLeak
If you put it with the numbers up. It's correct. Air in the system/lines takes a bit to work out.
I might be totally wrong. But K.I.S.S. applies here. Unless the pump was wonkered up to begin with.