Another idle question

[Bird]

98 SS Camaro - H/C/I - having idle issues. RAFIG / RAFIN are all good, fueling and VE are good, desired idle speeds are set to 900 rpm, but idle won't stabilize at 900 - stays at 1000 rpm instead. I can bi-di the IAC steps to 75 and the idle is perfect, but the minute I release control, the idle goes back up and the steps show 102. Cannot bi-di the idle rpm - stays at 1000 no matter what I enter. I can decrease desired idle air and the correction starts kicking in. It's almost like something else is commanding added air - what other parameters would affect the IAC steps to cause this?


Bird

[odd boy]

As far as I know the rpm at the dashboard is different than the real one for 98 camaro and trans am. Just confirm it with the scanner.

[Bird]

Everything is through the scanner - have rarely ever seen an OEM tach that reads close.


Still waiting for actual info for my question..........................


Bird

[joecar]

Under PCM control, the PCM thinks there isn't enough airflow so it steps the IAC open until it thinks the airflow is sufficient...

so this points to idle airflow.

Some of these threads may help:

Idle Tuning
showthread.php?4661-Idle-Tuning-Helpful-Info-Inside
showthread.php?14439-Idle-Tips-amp-Tricks
showthread.php?14153-scan-tool-wont-log-rafig-or-rafpn
showthread.php?14435-Need-help-Can-Start-Car-but-dies-when-I-give-it-any-throttle-before-going-to-CL
showthread.php?7011-ETC-cars-and-IAC-parameters
showthread.php?14544-Working-on-my-idle-tune
showthread.php?14794-Help-with-open-loop-%28cold-start%29-tuning
showthread.php?149-Idle-%28Transition%29-Tuning

More Idle Tuning
showthread.php?t=149
showthread.php?t=5866
showthread.php?p=86553 post #17
showthread.php?t=2630
showthread.php?t=473

Throttle Cracker/Follower
showthread.php?t=3568
showthread.php?t=4081
showthread.php?t=5406
showthread.php?t=5940

[WeathermanShawn]

Bird, if your actual question is "Are there other Tables that effect Idle Airflow", the obvious answer is yes (many).

This Tutorial may help you out:http://forum.efilive.com/showthread....ips-amp-Tricks

If your question is specifically related to IAC Steps through the Bidi-Control..I don't tune that way. I tune directly through the EFILive Airflow Tables listed in that Tutorial.

Idle is about a 8 hour job to do..even on a M6, so you may not just get an easy answer you can do in 5 minutes...

Hope that helps..Good luck..