YotaTech Forums - Which sensor to replace?

I have 88 4runner 22re. I am getting an engine code 4 which is the water thermal sensor. Not sure which switch to pull. There are two black connectors sensors just under the thermostat and a green connector sensor that sits under the intake manifold. Any idea which one it is. Getting the no start once engine warms up will crank but not start. Will start with a little gumout sprayed in the TB. validates the water thermo switch