Bad groung and or bad sending unit.
1990 Chevrolet Lumina temperature sender is located on the back side of the thermostat housing. The sender has a wire that goes to the temperature gauge.
It is an electrical device that tells back the engine temperature to both the temperature gauge and (where fitted) the engine management system.
The fuel sloshes back & forth as you accelerate.
Decomposers causes the fourth consumers to decay, causing it to bring back its nutrition to the environment... (:
Could be, sticky thermostat or low coolant level.
If the temperature gauge needle doesn't go back to zero when the car is shut off, it is possible that the needle is sticking. A little WD-40 or electronic spray on the gauge might fix the problem. There could also be a problem with the MAP Sensor or a Radiator Pressure sensor in the engine.
It is an example of resonance.
Could be low on coolant or a sticky thermostat.
check your conectors or the float might have a hole in it
on top of the engine in the back " not for beginings" the upper intake must be removed!
The temperature gauge is right in front of the fuel injection screwed into the intake just unplug the wire from the top of it and screw it out and screw in new one plug back up just tighten about a half turn past hand tight.
The gauge sender is located on the back driverside top of the head.