[Gmecm] Re: Vortec L31 oscillating at idle

[Darren Freed]

I had the same idle problem with my 3.4 DOHC v6.  This problem occurs
because there is a discrepancy between the desired idle rpm and desired idle
airflow values.  The OBD-II idle algorithm is very different than the OBD-I
algorithm: both desired rpm and desired airflow are used.  If they disagree,
the IAC hunts for an idle speed that will satisfy both criteria.  The only
way to fix the problem is to change the desired airflow and/or rpm tables in
the flashrom.  Hopefully you can do that with OBD-II TunerCat.

HTH,

Darren



On 3/19/07, Andrew Gibson <andrewsharyn at yahoo.com> wrote:
>
> The scan tool proceedure is in the functional tests menu. It has you start
> with the key on engine off, start the engine, then it initiates the learn
> commnad, and asks you to snap the throttle to get the engine up to the fuel
> cut out limiter. Then it's done. Takes about 30-45 seconds if your scan tool
> is capable. Mine is the Mac Mentor (OTC Genisis platform) Gm's OE scan tool
> of course should be able to do it.
>
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