Does IAT sensor influence engine idle speed?

[austinrick]

How much does the Intake Air Temperature Sensor impact engine idle speed, cold and hot? Since replacing the battery with new, my '93 3.0L has been idling really slow. New IAC valve hasn't changed idle behavior. She starts up cold (summer cold, that is), idles up for a few seconds and drops down to where I worry a little about oil pressure.
Throttle Position Sensor shouldn't affect idle speed, but it was just replaced too, due to a TPS code (new one really perked up the engine!).
OBD1 reader hasn't shown any IAT sensor related codes, but you never know. Some readings:
4.65V coming from ECM to sensor (Haynes calls for 5V)
30K ohms at the sensor pins cold (Haynes wants 27K)
12.5K ohms at the pins after 5-6 miles of driving (Haynes wants, I think ~8K at ~170°)
Could the IAT sensor be sending signals that keep the idle way low?
TIA

p.s.- While I'm at it, how can those of us without any sort of tach on our Rangers get a reliable rpm reading?

 

[superj]

no idea on your main question but you can get an inexpensive tach from the local auto parts place or get build one from some computer parts that is a bar tach.

i think the bar tachs look super cool so i would do that

DIY Tachometer (RPM Meter)

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here is a portable one for while you are working on the engine, it uses a piece of reflective tape of the front of one of hte pulleys

Build a Simple Tachometer at Home

Build a Simple Tachometer at Home: Hey there, in this instructable I will show you how you can make a simple tachometer at your home, to keep this simple i have given great details with simple explanation that anyone could follow. What is a tachometer? well to answer this let me expl…

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