First, that vintage engine may be computer controlled fuel injection, but On Board Diagnostic were not installed until 1996MY.
IHMO, not likely the fuel pump. They tend to work or not work and usually "announce" their "departure" by making load noises in advance.
That vintage engine would have a TFI ignition module which don't like to get hot. Some were mount on the side of the distributor just below the cap. Others were mounted on a thick aluminum heat sink bolted to the fender. Again, these tend to be a hard failure.
Find an old fashion repair shop and determine if your motohome has the HD radiator. It should also have the auxiliary transmission cooler. If not, get them installed. Also check to see if the fan clutch is working properly.
I think most of the other items are red herrings.
