More likely you have a bad idle speed
controller or possibly the valve. This is common way for the controllers to
fail.

  Slight thread deviation here...

  My Digifant engine has begun to occasionally idle very low, like just
above dying...this began after an O2 sensor swap from a heated sensor to a
single wire one.   This low idle condition occurs when I have re-started
after enough time for the exhaust system to cool down but the rest of the
motor is still fairly warm....like a highway trip, then 20 minutes in a
store somewhere and back to the van...it starts and runs fine, normal...but
when I let it idle down for the first few minutes after the restart....it
ticks over at about 3-400RPM, just barely stays running...Once it's run a
minute or two, all is again good.

   I have not yet opened the lid to listen for the Idle control valve's
hum...nor have I ever figured how to test my throttle control switch, but
that switch does "click" fine