on ae92 the temp gauge has an earth wire to it
if this earth aint hooked up it reads hi off the gauge
the earth wire (brown) runs thru the yellow plug which is below the stereo on left hand side
these wire run thru the firewall to the engine and earths on the block
and the idling stalling prob could be due to idle or fuel cut solenooid havin no earth
so check to se eif that brown wire and the wires on the carby have an earth