Common problem on early CFI units. Put a 1.1k ohm resistor between the two wires for the ECU coolant temp sensor under the inlet manifold. A new sensor will not work. There was a technical bulletin on this when I was at Ford in the early 2000s.

What is happening is the car thinks it is too cold all the time so never gets off choke completely. This removes the full choke sonbrings it back into tolerance.