On the Fords. the Triton motors have COP (coil) issues. a lot that have a misfire are due to a bad coil. rain can create a problem, but most coil failures are on the engines that haven't been maintained properly. the gap on the plug gets large and the col has to work harder to create a spark. that is when the coils start going bad. I have 91k miles on my V-10 and the plugs were done at 50k, will be done again at 100k. I have the OE COP`s and boots. I do however carry 2 spares with me, because they can fail. but the chances are slim on a well maintained engine!
And BTW, I forgot about this before when I posted. on a lot of the late 90`s and up engines (usually OBDII), when the PCM sees a hard misfire it can shutdown the fuel injector on that cylinder to protect the engine and cats!
Good luck on finding something.
