I think the topic basically says what I want to know. I have suspicions that my IAC is wore out and that I'm possibly maxing it out but generally that I'm not getting the proper IAC counts. I have a scan tool to check it, I just need to know the approx range that I should be in. When fully warmed up, the engine idles at 700rpms in drive and just over 1,000 rpms in park.

 

At operating temp you should see ~20-30 IAC counts.

Much lower than that and you want to take turns out of the min air screw, which will cause the IAC to open more, showing a higher IAC count value.

Much higher than that and you want to turn the min air screw inward, which will cause the IAC to close more, showing a lower IAC count value.

 

Wow, thanks for such a detailed answer. That's exactly what I needed to know. Much appreciated.

One quick question though, is that 20 - 30 in park or drive? or does it matter?

 

in drive.

 

Actually, I adjust min air to get 20 counts IAC in park at operating temp.

 

oh i was told by tpis to do it in drive ,but im sure alot of you know they are not always a great source of info.

 

Well I'll just try it both ways and see which one works best for me and go with it

 

Hello. I know it's an old thread but I wanted to ask if changing the minimum idle position screw could hurt the air fuel ratio? I have a 383 that was dyno tuned with the chip burned for that tume along with the idle controlled to 800 rpm since the cam.is big. My IAC count is just about 0 at normal operating temperature and the tps voltage is .73 volts which for speed density is ok. If I close the blades to get the IAC count up to maybe 20 or 30, would that cause the car to run noticeably richer at WOT based on the map of throttle position to fuel?

 

No. Air is air no matter where it comes in from... throttle blades or IAC.

 

Thanks, makes sense.