my car has been idling funny since i got a ported throttle body. so i ataped to check my iac to see if i needed to drill out my throttle body hole. well it read 0 all the time. so i thought i had a bad sensor, but put my atap on a friends car and the same thing zero? what gives? <img border="0" alt="[Banging Head]" title="" src="graemlins/gr_banghead.gif" />

 

I noticed the same exact thing with my car. I also have a ported tb but the IAC always reads zero as stated before. I have autotap v2.03.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by DailyAluminumBlock:
<strong>I noticed the same exact thing with my car. I also have a ported tb but the IAC always reads zero as stated before. I have autotap v2.03.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Are you reading the "desired IAC position" one? That is the only one that returns non-zero on mine.

-Dave

 

Nope.

 

The IAC is NOT a sensor it is a STEPPER MOTOR that moves a pintle (valve) in or out to raise or lower idle speed. Pintle goes IN, air flow is reduced, idle speed drops. Pintle retracts, air flow increases, idle speed goes up. The PCM tells the IAC whether to move the pintle in or out. Numerous devices give info to the PCM to help the PCM decide what the IAC should be told to do.