PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

IAC too low

Thread Tools
 
Search this Thread
 
Old May 7, 2007 | 11:14 AM
  #1  
marthastewart's Avatar
Thread Starter
TECH Apprentice
iTrader: (1)
 
Joined: Apr 2006
Posts: 301
Likes: 0
Default IAC too low

My 99z runs great but the afr at the idle rpms is very rich. I posted this on tuners but have not gotten much response

I read how to adjust the IAC but it does not do much. The following is what I read to do and what I have.......

Said to get TP Voltage between "40-60" My TP voltage 55. Thats good. Said that the IAC count is suppose to be between "60-80 non cam cars" mine is 16 when warmed up. Now I did not actually see the "IAC Count" for a selection. I did see and log the "IAC Desired Position" and "IAC Position". Both of those are 16.

The car runs/idles great, I just dont like to see a 12.11 afr at idle. I think this might have something to do with it. I do have a ported TB but did not mess with drilling that hole they said to do if your IAC is too high. How would I make this go up, fill inthe hole a little? And am I even logging the right things?

TIA
__________________
Reply
Old May 7, 2007 | 01:00 PM
  #2  
SSpdDmon's Avatar
TECH Addict
iTrader: (10)
 
Joined: Jun 2004
Posts: 2,918
Likes: 0
From: Commerce Twp, MI
Default

Fueling doesn't really have much (if anything) to do with the IAC valve. That's corrected with the MAF, VE, and commanded AFR tables. Either your car is commanding a rich condition at idle or your fueling is off.

To get the IAC steps up, you want to back out your throttle body set screw to close the blade slightly. This will make the IAC valve open more to compensate for the reduced airflow around the blade, which will read as a higher number of steps. If your set screw is backed all of the way out, then there's little you can do. If the IAC steps were too high, you would open the blade some with the set screw. You follow?
Reply




All times are GMT -5. The time now is 07:54 AM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE