Have a 1997 Ford Ranger 2.3liter 5 speed 235000 miles. Have intermittent stalling , engine not up to operating temp., when stopping. after engine get to proper temp. no problem. Replaced IAC Valve. Checked oxygen sensor, seems to be ok. Used propane to check for vacuum leaks,. None found.

What would be the next step? TPS unit? Water Temperature sensor to Computer?

Thanks, Bill