Check to see if your engine oil smells like diesel fuel. Sounds like the diaphragm is out of the fuel lift pump. When the diaphragm goes bad, it will leak fuel directly into the crankcase.
It's an easy fix, lift pump is external. Remove a couple of lines, a couple of bolts, clean the mating surface. Install new pump with gasket. You may need to purge the line of air, from the lift pump, to the first connection beyond the lift pump.
IIRC, I found an aftermarket pump for around $35.00 plus shipping.