Oil pressure gauge is stuck on 80

Hello,

This could be due to a faulty pressure sensor or a bad stepper motor for the gauge.
The oil pressure sensor is located on the top part of the engine, behind the distributor cap.

Test the sensor by using at multimeter. If the resistance reads out of limit for the sensor that it is a bad sensor and needs to be replaced.

I have attached diagrams for your reference.

Please let me know if you have any questions.
Thank you.

https://www.2carpros.com/articles/high-oil-pressure