Wow, you have already done a lot to the vehicle that I would have suggested. Since it runs normally when you turn it off and then on for a short period of time, it sounds like it could be related to an electrical issue.
I realize you replaced the fuel pump, but have you confirmed it is within spec? Also, are there any odd smells or smoke from the exhaust when this happens?
Let me know. Also, try scanning the computer to see if there are diagnostic trouble codes stored. This vehicle has an OBD1 system and doesn't require a scanner to get codes. All you will need is a short jumper wire or even a paper clip.
Here is a link that explains how it's done:
Try scanning and let me know if there are codes and what they are.
I will watch for your reply.
Friday, March 11th, 2022 AT 8:30 PM