I had same starting problem. Turned out it was fuell housing. ( this is a part on the engine from driver side where you attach fuell filter )
He said it pumped fine. When they are holding pressure and not bleeding air it will be pretty stiff primer pump.
It was finally repaired 4/24 replaced 3 injectors even though they tested ok, Volvo's warranty covered repairs, dealer did try and charge for a fuel filter they said was leaking, until I told them they put it on .
