Simple fix is usually a new oil pressure sending unit. It could be unplugged or the line broken somewhere. If none of these are the case, it's probably a bad gauge and will need to be replaced.
Bad oil pressure sending unit?
Your temp gauge is a very simple circuit with few things to go wrong. Your temp sensor may be bad, the gauge maybe bad, or the connecting path may be bad. Sometimes if you have taken the gauge pack out, it does not seat right when it is reinstalled. The connection inside the dash is all pressure and prayer.
A bad sending unit in the gas tank.
It is most likely the oil pressure sensor, located on the front of the engine block near the oil filter. There is also a slim possibility that the gauge in the instrument cluster is defective.
Reverse airflow feels a chamber inside the gauge and reads the pressure equal to the inside of the tyre its that simple. Same for air compressure, when the pressure is applied it seals the valve on the gauge end then back pressure fills the chamber inside the gauge when you release the gauge from the tyre valve the pressure has gone!!
More then likely you need to replace the Thermostat.
Get a rod done.
The problem could be a dirty sensor or the sender is no good.
it will work but you have to use a pressure regulator in line so you can set the fuel pressure down to 6 psi. for the carburetor
Pressure gauges work based on the principle that a fluid or gas exerts a force on the gauge's sensing element, which then deflects or moves in response to the pressure. This deflection is converted into a reading that indicates the pressure being measured. The gauge is calibrated to provide an accurate and precise measurement of the pressure exerted on the sensing element.
The fuel tank pressure sensor is for the EVAP system. It has nothing to do with the fuel gauge sending unit.
1984, Corvette the fuel gauge stays at 1/2 full all the time. Plaese help.