[Gmecm] $8D IAC stalls engine on decel

[Tomas J. Sokorai Sch.]

On Sunday 27 August 2006 20:38, David Allen wrote:
>
> Set the idle speed high at minimum airflow screw; then turn off engine and
> want for ECM to power off. Connect ALDL program.
> Then re-start and allow engine to be FULLY warmed up.
> Now lower minimum airflow until you see 4 or 5 IAC counts on the scan data.

I'll try that, thanks.

>
> The reason to start high and then lower the min airflow setting, is to
> prevent the ECM's IAC throttle-follower function from defeating you.
>
> What kind of throttle body are you using?  The original Bosch one?

The original that came with the BMW. I adapted it for a TPS from a GM TBI and 
adapted a V6 IAC & housing to be externally attached with hoses to the TB's 
idle bypass attachments. 
The only way to set the minimum airflow is by means of the throttle stop on 
this TB.

>
> What kind of VSS did the Bimmer have from the factory?  If any?  Even if it

None, mechanical speedo. The E21 is as simple as a car can get ;)

> had one dedicated to the Cruise (or 'tempomat' IIRC) you might be able to
> adapt this to your system using a divider or buffer of some sort.

Maybe the E30 series has a VSS I can adapt ....

>
> I have run without a VSS with no stalling issues.  Really it is not
> necessary; but it is nice to have! My EFI Boat has no VSS (BSS?) and it
> never stalls.

Well, I think the minimum airflow will do the trick ... but I still think the 
code should get sanity checks, and not let the IAC get to zero.

>
> Glad your project car is working well!

In part because of you, thanks for the ideas! :)

-- 
Tomas J. Sokorai Sch.