intermitten missfires on acceleration/downshift also

2001 Tundra TRD with fifth wheel receiver hitch in bed for Scamp 19' 5th wheel trailer. My baby.
I have a new issue this year with repeated, mostly after refueling that my truck motor will die and everything stops including the power steering. Good clue I guess. Battery light comes on. HISTORY: open hood wiggle battery connections and ensure tight NEXT Starts right up so think I have electrical issue. Repeats again 4 times in 3 months and the last after even changing the battery connectors. BOTTOM LINE: I DON'T BELIEVE IT IS AN ELECTRICAL ISSUE and no codes have been checked. Sorry but it does fine after getting it started if I would mess with the electric connections. AH, A CLUE. Don't mess with connections but just sit tight waving the traffic around for a minute or two and it would START RIGHT UP. Warmed up in park watch tac slowly climb to 2600 and it misses. Go 50 mph in a 65 and tromp on it and it misses. When it is done MESSIN with me I can drive interstate at 70 to 75 mph for an hour with no issue. But after next refuel we have issues again. Interested to know if these symptoms ring a bell with anybody. I think this is my new member introduction. Married - 76 years old - fiddle player and need to get to my gigs 100 miles away with my camper to have fun and let the wife have the cabin to herself. Twice a month I make the trip and sleep in the camper so I don't have to drive the 100 miles home in the dark. Now I am stuck home. Poor wife.......
EDIT: 250k on truck original motor runs great until this happens.

 

Welcome from NY.

Wish I could help. Try posting that question in the first generation forum or Ask the Toyota Mechanic forum.

 

Welcome from LA (Lower Alabama)!

 

Thank you very much. Will be looking in those particular forums (soon as I figure out how to get to em - which I am capable of) and I will do a search in those forums for the miss firing as instructed in my introduction to this site. If I can't find the subject I know now to repeat this post in them. Thank you I want to be a good user and not an annoyance of course. Just been a bit frazzled by all the you tube videos but it is fun learning. I am taking the unit to a reputable shop with diagnostic equipment today to also get there take on this situation. A young person I know said it might be the fuel pump and we discovered the complete replacement apparatus for the tank was over $615 at Auto Zone and around $300 at Rock Auto and same price discrepancy for just the pump. I will be asking for a quote from the reputable shop before approving the work to include parts cost. Just wanted to share that unusual price difference with you.
Thank you I will now go find those individual forums. Have a great weekend.

 

Love the Critical thinking from Bakershack also.
Quality people and communications here so far.