The '74 has the 311 906 161 C thermoswitch (not a thermo-time switch). Actuating temperature from my D-Jet parts page:
311 906 161 C : -6 to -14 deg. C / 21 to 7 deg. F
The cold start system is designed so that the CSV will be actuated only during cranking, and only when the temperature of the thermoswitch is below the setpoint above. The thermoswitch and the CSV operate independently from the ECU.
https://members.rennlist.com/pbanders/DJetParts.htm