Same problem

[VTChavez]

Replaced ECT sensor and truck still won’t run until engine warms up. Will start and run if you keep accelerator depressed to at least 1000 rpm.
97 ranger, 4.0. Any suggestions anyone?

 

[RonD]

Was it the ECT(engine coolant temp) sensor or ECT sender you replaced?

ECT sensor will have a grey/red stripe wire
ECT sender a red/white stripe wire

ECT sensor is used for the Choke, cold engine operation

ECT sender is used for dash board temp gauge

You may need to test the ECT sensor wires, because outside of a computer issue thats the only sensor that is used to set cold start choke mode

 

[VTChavez]

I am pretty sure I did The right sensor. Has two wires on it, one gray and red, the other is green and red. I checked with the schematic and verified continuity between the sensor and the PCM connector. I will double check the wires again. Anything else I can check that you could think of let me know. Thank you.