I don't know if all the coils are directly attached to the spark plugs, or if there is a wire. I had a friend complain that he had some spark plug wires replaced recently, and although all the spark plug cables are only about 3" long, some are 'long' while others are 'short'. Even though all are within 1/4" of each other.
So what was happening with his car was the spark was not reaching the plug properly. He has coil packs on his car too. So the next mechanic could tell what wires where short, and has spark burn marks on the end of them.
You can take the RV to a Auto Zone or many other parts stores, and ask to borrow a code reader. Usually they will allow you to borrow it for a few minutes. It should tell you what cylinder is not firing correctly, or what might be wrong with it.
My 5.4L Ford work van had a leak on the coolant line going to the intake manifold, and that also zapped out one of the coil packs. They did not find it until the second one went out in a week.
Good luck!
Fred.
Money can't buy happiness but somehow it's more comfortable to cry in a
Porsche or Country Coach!
If there's a WILL, I want to be in it!
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