As already said top dead mark on outer edge of pulley can be out , also if engine does get turned over without chain connected to cam shaft , diesel pump can end up firing on number 4 instead of number one.
There is pump marks on the diesel pump ,you have to take brakes vaccum pump out and they are there, there is a nick out of one of the teeth and a mark on the case but they are difficult to see.
Hope this helps.

Lee