A GN Promdata Question

[Mark Romans]

I spend a bunch of time messing with the PID for idle and iac control and
what ended up fixing my idle problems was smoothing the spark map
transisions in the area of the map used for idle.
I had advanced the timing in the low load areas of the map and when rpm's
were high there was a lot of advance, so the iac would retract to try and
bring the idle speed down.  Then when rpm's dropped the timing retarded and
the iac couldn't catch the idle before it dies or it would occillate up and
down, drove me crazy!
Maybe this little direction will help.
Mark
-----Original Message-----
From: JTesta1966 at aol.com <JTesta1966 at aol.com>
To: gmecm at efi332.eng.ohio-state.edu <gmecm at efi332.eng.ohio-state.edu>
Date: Saturday, June 26, 1999 5:40 AM
Subject: A GN Promdata Question


>Well guys, actually 2 things
>
>1) What is an "Idle speed inverse quantizer" for? What does it do, and what
>can be effected if you screw with it? I'm having a hell of a time getting
my
>cold idle right in my 86 GN. I've tried everything I understand in the chip
>and nothing seems to help. The peoblem happens warm too, but slightly
>differently. On cold start I get  fast idle after a few secs. Which BTW
seems
>to lower itself too much, I believe this is the lean calibration GM used? I
>played with low coolant A/F and moved it in a couple steps to its current
>13.8:1 but didnt really make a difference. I've tried playing with IAC
park,
>warm idle IAC park, low coolant temp A/F., but nothing I touch seems to
make
>a difference. I write down all the changes I make so I know what to put
back
>and whatmade a difference and so far I think that quantizer thing is the
only
>thing I havent screwed with. Do any of you guru's have any suggestions? If
>any are willing, I'd be happy to send the bin for this chip and get
>comments/suggestions on where my tuning has fallen short. Oh, BTW its an
86-7
>cal.
>
>Thanks in advance
>Jim
>