Maybe the sensor. But first I'd get a working ECT sensor. You say it shuts off because of it getting hot? How do you know it's not shutting off from something else if you don't know the ECT temp.
98.5 SVT
91 Escort GT (almost sold)
96 ATX Zetec (i brake to watch you swerve)
FS: SVT rear sway bar
WTB: Very cheap beater
CEG Dragon Run - October 13-15