Miss fire/running rough. Water pump went out and blew coolant all over engine. Had it replaced and it ran fine. Washed truck but not under the hood and now it runs rough/misfires.

You are shorting out on your plug wires and coils from the coolant being sprayed over the engine. I would get some electrical contact spray and pull the plug wires and spray them and the coils. I would even clean the battery posts and the ground.

I have a 2002 4.7; got water down one of the plug chambers, and it caused one of my coils to misfire. Blow compressed air into each plug chamber after removing coil/plug wire the remove plug and check for replacement

I have that problem right now. I just changed my plugs. Mine only seems to do it when it's real cold.