Par Ave hard starting when cold

I have a friend that bought my PA and is having a hard time starting it when it gets cold. It always starts-eventually. You just keep trying it, stall, start, stall, then it will eventually run beautifully. It did it last year, and now again tis year, BUT it has a new engine in it. Thus I have deducted - water in the gas, easy fix with dry gas. OR...............fuel pump. Does anyone have any ideas???? It is below 0 here in western New YOrk!!!!!

A bad fuel pressure regulator can cause this problem it is the first place I look when I get this condition on a car with a 3.8l engine.