Car won't accelerate after it runs about 10mins or it is had rainef

The problem appears to be related to the rain...something got wet, and hasn't dried out yet. Scan for fault codes which may lead you to the cause of an apparent misfire. The PCV valve is in a tough spot, and it will not be the problem. It only vents engine crankcase vapors over to the intake to be burned off. I am also thinking fuel pump or the fuel rail pressure sensor (P0193 code). That's not the regulator...just the sensor...you have both. If code P0193 appears, the scanned will show fuel pressure. Normal is about 50-60 psi.

Another thought. Since all this started after driving through rain, water may have entered the gas tank through a rusty spot on top, or possibly at the fuel pump assembly seal. Water will settle to the bottom of a gas tank. Maybe you can siphon out into a gallon glass jug and look for water at the bottom, and continue to do so until it is removed. You can separate gas/water by carefully pouring this gasoline off the top and discard the water at the bottom. Water won't damage anything. It just has no energy and won't power the engine one bit. And don't run the car with less than 1/4 tank gas. Bad for the pump.....pump runs hot....picks up sludge. I have the same exact car, 2004 Taurus w/Duratec engine.