IAC

[ARTHUR OKUN]

You wrote: 
>
>
>     I'm using a Wolf 3D system which doesn't allow for control of the 

>     standard IAC, thus I was thinking of either using:
>     
>     1. the old style solenoid switch that opens the throttle a bit 
when 
>     power is applied.  Requires the original IAC mounting hole to be 
>     blocked off.
>     
>     2. a temperature sensing bi-metal type air by-pass valve as used 
on 
>     many Nissans.  Requires blocking of the original IAC mounting 
hole 
>     also.
>     
>     3. Nothing at all.
>     
>     Dan        dzorde at aesprodata.com.au
>
>
>______________________________ Reply Separator 
_________________________________
>Subject: Re: IAC
>Author:  diy_efi at coulomb.eng.ohio-state.edu at INTERNET
>Date:    05/2/96 4:25 PM
>
>
>You wrote: 
>>
>>
>>     
>>     On the subject of the GM IAC(idle air controller) for the TPI 
>engines. 
>>     Does anyone know of a replacement, working of sensing the 
>temperature 
>>     or similar, ie. some sort of bi-metal spring system.  The 
problem 
>is 
>>     that I need some sort of idle stabilisation on a TPI system but 
>the 
>>     ECU does not allow for control of the standard IAC.  
>>     
>>     Is it possible to leave the IAC off all together?  
>>     
>>     Any ideas will be appreciated.  Preferably the parts should be 
>>     available of Australian cars, since US parts are to expensive 
>over 
>>     here.
>>     
>>     
>>     Dan        dzorde at aesprodata.com.au 
>>      
>>
>the iac is just a little stepping motor  gm bottoms it shut at start 
>and then backs it off a a certain number of steps to control idle 
>mixture air and also as a deceleration valve during throttle release 
>closing. what sort of ecm are you using?
>ford uses a solonoid thats pwm to do the same thing  but ive heard the 

>gm stepper works better and smother as long as the valve lead screw is 

>kept clean (i own a iac gm ).
>maybe i could design a little gaget using a pic16 up.
>Does that wolf unit have any output that could control   throttle air 
input   you realize that its a multiphase ac  stepping motor
could   probably make a circuit using cheap ics  that  would  open it 
realative to tempature or how about a super simple circuit to open or
close it  with just   a pair of push buttons  when you read it  with
a scan tool it just tells you the number of  counts open   80 is pretty 
much maximum but it will send it more if it thinks the iac is sticking
so i guess you could concider it a feed back loop .>