CIS basic idle/mix ballparking advice

[jdbubb at verizon.net (Dan Bubb)]

I'd start by backing off the primary throttle plate stop screw. It's right 
on top with an 8mm locking nut and usually some yellow paint to hold it.
Back that out until the plate is fully shut then screw it in just enough 
that you know the plate has been opened some. The plate will tend to bind if 
it's allowed to close all the way and I believe that is the purpose of the 
stop screw, to hold it just a tad open. Alot of times people don't realize 
there is an idle adjustment screw and use the primary plate screw to adjust 
idle, so maybe that's it..
Also, make sure the secondary plate is closing all the way. Sometimes they 
will bind open just a bit.
If those two aren't it, then it's either a vacuum leak, auxilliary air valve 
that's not closing fully or an intake duct not fully seated.

(If I were you I'd ditch the CIS and go to Megasquirt. It doesn't care about 
all those goddamned leaks ;^) jk!!

Dan

----- Original Message ----- 
From: "C Boyko" <roccit_53@scirocco.cs.uoguelph.ca>
To: <scirocco-l@scirocco.org>
Sent: Saturday, July 30, 2005 9:01 AM
Subject: CIS basic idle/mix ballparking advice


> Okay, this is a straight CIS car, no Lambda/O2 sensor, no frequency valve,
> no DPR. No magical mutlimeter/dwell meter number to offer assistance.
>
> Just trying to get it ballpark set up for mix, it will get it's knock
> sensing ignition put back in before I take it for proper gas analysis.
>
> Right now the timing is advanced from the stock 6*BTDC, maybe like at 10 
> or
> 12. This is straight TCI-H.
>
> I've installed a new auxilliary air valve, since the other was FUBAR
> (and this is one of the few times I've been glad to have that Fox 
> manifold,
> it puts the AAV in a spot that's easier to access) . Anyway,now I have to
> reset idle, and adjusting idle with the idle screw on the TB doesn't 
> change
> it much, and even with it fully closed, I can only get the idle down to
> 1500. I've checked for vaccuum leaks (and that almost sounds like a 
> massive
> one eh?) and can't find anything. So that leaves the mixture screw on the
> fuel distributor. Any helpful tips for setting this up? Thanks...
>
> Cathy
>
>
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