how critical is 10-30 for iac values???

[Maltman]

I can send you the tlink file if needed, but what I'm seeing on the beginning of my "tuning" mission is that my iac counts are high.

I set the iac per red's method (set idle speed at 650 with iac disconnected). IAC plugged in and car idles fine and isn't stalling or suffering from a stumble.

Should I focus on getting those numbers lower, or is this trivial?

Specifically, the warm idle in gear gives me iac counts of 50-52 or 20-22%. Int and Blms appear ok. Before I start going into the wot tunes, I wanted to make sure the basics are correct.

What do you think?

 

[MistaScott]

Those aren't terrible numbers. You should be below 40 ideally. The number is really just a measure of how hard the ECM must work to maintain idle RPM.

The idle RPM is dicated by the ECM. The idle screw just partially opens the throttle body to let more air in at idle, as I recall...

 

[scottyb]

I've never seen Red's method, so I can't comment on it.

I've been pretty happy with ~10, TPS ~.40

www.vortexbuicks-etc.com is the gory details.

 

[strikeeagle]

The CHIP commands the idle speed, PERIOD. You do not adjust IDLE, nor do you adjust IAC, you adjust MINIMUM AIR. IAC is the result of your MINIMUM AIR adjustment, and the condition of your car.

The idea is to back off the minimum air screw until it no longer contacts the throttle linkage. Then, turn the screw in until it just starts to contact the throttle linkage and you achieve the desired value of IAC, all the while keeping TPS within range. Everything should be done with a COMPLETELY warm motor.

Why this is such a mystery to so many folks is beyond me. A car in poor repair typically has one or more of the following "issues":

1. Misadjusted TB minimum air screw.
2. Dirty or weak IAC motor.
3. Vacuum leaks.
4. Worn or faulty TBs (e.g. blade does not seal bore).

 

[GNRick]

I couldn't get my IAC down to the desired level until I removed the up pipe and sprayed the throttle body with carb cleaner to clean it out. IAC came down to around 20-30.

 

[Maltman]

...just trying to figure out this count business. Just setting the car to idle "without" the iac helping at all was established as a way to prevent the rapid decel stalls....I guess it worked for me, but that was with my stock intake setup and 009s. Maybe I don't need to do it that way anymore?

However, I have another potentially dumb question: Is it possible that my "angle boss" deal could change the iac counts so I won't see the "normal" iac counts?

In the meantime, I'll set it like you all are saying and see how it responds.

Thanks,