My car does the same thing on start up. I believe it is the 2 step colder plugs that cause this on my car. When the combustion temp is low the spark plug is not hot enough to ignite the gas everytime, unlike a stock plug. I just let my car warm up and then drive her easy every morning.
I pulled all the boots and sprayed them with an ignition spray that lubricates and dries any moisture. I then sprayed the harness down that is inside the cover.