Hello! I just rebuild my engine. Its a m104.990 that is in a w124 now.

Just got the new rods and head gasket inn, and when i started cranking it to get oil to the turbo nothing happend, and the oil pressure sensor shows nothing eighter. Did pull out the filter to se down there while cranking, but no oil comming..
everything worked fine before i pulled out the engine.
And im sure i got everything right back together.
Anything else than a bad oil pump that it could cause this?
Got another oil pump, but hope that it would be somthkng else so i dont have to pull out the engine again for that.

Would be really thankfull for any answer!