Yancheng is the MFD for Jinma tractors. Since you say it has a Y385 , that engine is MFD by Yangdong.
All the Y385 I have seen have had glow plugs ..... not all have had compression release.
The white smoke indicates it has fuel deliverly.
Look under 254LE Glow Plugs here .......
Jinma Dealer, Wood Chipper , Compact Jinma Tractors
The fuel return line runs/lays on top of the injectors. If the return is leaking... not really good but doubt if that will effect cold start. If the injector itself is leaking could??
A lower radiator hose coolant heater works nice as a pre-heat.