When you have that kind of thing happening to the instrument cluster, it sounds like a cluster problem in itself, or a short to ground or short to power in a wiring harness.
This car was designed and manufactured before the use of CAN networking, and is OBD-I for diagnostics. As such, the instrument cluster is not influencing the starting of the vehicle in any way. This vehicle does not even have a PSOM -- a programmable speedometer / odometer module.
Wiring issues and a short of some kind the circuitry to the instrument cluster -- looking perhaps in the ground circuit, is it would influence everything more than likely -- is a main area I would focus on.
For engine performance, check the inertia switch first to see if it has been tripped accidentally. This cuts off fuel supply from the engine. Following this easy check, normal engine diagnostics are in order. Good luck.
Unfortunately there is no way to determine exactly what repairs the “others” have attempted.
I’d start from scratch and move forward with normal diagnostics - spark - fuel - air, etc..
I too suspect a ground circuit issue concerning the instruments.
This is likely to be a tough one - good luck indeed!
