IAC modifications

[bruce plecan]

In response to JZarli.  I'd tried to reach you before but never heard
back from you.
     The ECM, as I see things has a certain latitude with timing,
mixture, and IAC counts at idle, there is a "suggestion" in the ECM
for the IAC count, it will juggle the mixture, and timing to get
a specific idle speed, then if that doesn't work will start changing
the IAC count which is a metered vacuum leak.  Now the ECM knows this
so goes rich as it opens, but then since you have a "big" cam the
vauum signal/or grams/sec changes, and the computer then tries to
juggle even more.  So now it's trying to make "large" changes to
smooth out the idle, and look for a suggested speed.  By reducing
the amount of taper, it can make these wholesale changes without
this large vacuum/gram/sec change, and then blend the timing/mixture
to get the idle right.  When I first started the IAC count was 
initially 30something, and then would go to like 50, and then 10.
This is with a slow sampling scanner, so I can only quess about some
of what the ECM was doing.  Once I got the tapers right, it would
immediately be at 30 and then rapidly drop, and now usually rests
at 5 or less (off the top of my head).
    One other thing (for everyone following this), you might think
about is your PVC valves.  I don't know what all your running, but I
went thru looking for the smallest orfice that I could find.  At
one time on a Sunday, used a 1/4" restrictor.
    On some other cars that I've done, I also put a restrictor in
the brake booster line.  As I recall it was 5/16", you'll know
if it's too small by how large your calf bulges, when trying to stop.
    Ya'all ask too many questions (jus kiddin), I've wound up startin
to give alot of my secrets away. 
    Please remember there are some programs, and other cures for
some of what I've discribed.  I'm not a ME, EE, or anything related
to them, just spent a bunch of time on a couple cars, and am relating
what worked for me.  
    Once I got as close as possible with injectors, I'd get ahold
of Jeg's (800) 345-4545, and get an adjustable regulator.  If your
real good with a dremel, and can con your dentist out of a used
1/8" grinder, you can grind the weld, out of the FPR cover, take it
apart, clean up the adjustement screw put it back together.  Just
to make tinkering easy, I removed the FPR cover, and cut a 3/32"
peice of steel to replace it.  Then I used a Mallory adjustable
FPR, Use Earl's fillings, and AN line if you go this route.  But,
I was able to make adjustments quickly.
   Before I shoot my mouth off about the numbers you mention, I gotta 
look at some parts in the garage.
  Hope this helps  Bruce