Hello and welcome to 2CarPros. Being a 1995 you cannot easily scan it for codes, however I would suspect a faulty coolant temperature sensor or the wiring to it being it isn't a constant problem. Your vehicle uses two sensors, one goes to the ECM and the other to the gauge in the dash.
GM # 15326386 is the ECM sensor. It screws into the intake manifold next to the thermostat housing. A trick to changing it out without draining the coolant is to have a cold engine. Start removing the sensor until it is almost fully out. Now squeeze the top radiator hose hard. Release it and as soon as you do remove the sensor and screw the new one in, if needed a helper on the hose can make it much easier. Squeezing then releasing the hose will create a small vacuum inside the engine for a couple seconds, that is usually enough time to swap the sensor and only get a tiny amount of coolant out of the system.
You can test the sensor first if you have a multi-meter. Simply check it's resistance using the table I posted. However, you would need it to be acting up while this happens to be sure it's the part that's failing.
Another option would be to find a shop with an older scan tool that can read the data from the PCM and see what it shows while it is acting up. However that could take a while unless it always acts up.
I would also look at the connector real close, corrosion or damage can cause a lot of problems, many times more than failed parts.
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Wednesday, February 6th, 2019 AT 6:20 PM