Cold idle stalls

[scott4tel]

1988 2.8 v6 107k miles runs strong. Problem is in cold start situation it will not idle. I changed IAC Valve an no change with exception of opening (compressing plunger by hand) valve manually then it will idle. Logic tells me the IAC is not getting signal because a related sensor is non op. The IAC does not know its in cold choke so it does not open.
Which sensor could do this?
What other ideas to you have?
Thanks

[woody90gtz]

If it is non-operable it sounds like a problem with the wiring to the IAC? The IAC will be open several counts even when the engine is warm. Cold should not matter. A bad CTS will cause an over-rich situation, but it will actually be less noticeable cold than warm.

[scott4tel]

Thanks for the response. I did buy a Coolant Temperature Sensor but haven't installed yet. I wanted to ohm out both side by side to see if there is difference. I get 2600 ohms at room temperature on the new CTS.

I was hoping somebody had "been there done that" with this issue.