Temperature alarm and codes 14 and 43

I have a 1991 Oldsmobile Cutlass Cierra with 3.3L engine. On unpredictable occasions the engine dies just after the Temp lamp and Service Engine lamp comes on. It appears to be flooded with fuel. It also has a temp guage which remains unchanged but works properly under all other conditions and there is no indication the engine is hot. After 10 or 15 minutes the engine starts and runs fine and the service engine and temp lamps are out. I assume both the light and guage work from the same sensor but there appear to be two sensors in the right side close to the water pump. Unplugging both do not kill the light when the switch is on. It appears the ECM is getting a low temp input. Is there a test to further define the problem and which sensor is the one to use?