<VV> Production ECMs Re: EFI Info Re: OBD-II for Corvair

[FrankCB at aol.com]

Mark,
 
For you guys using ECMs from production vehicles, how do you go about  
CHANGING A/F ratios and ignition timing from the stock NON-Corvair settings to  
fit what's needed in your Corvair, especially if you've made modifications 
to  the stock Corvair?  On the MegaSquirt units you can take advantage of the 
 feedback from wide-band O2 sensors for the A/F and can use Ray Sedman's  
SafeGuard with optional display to help you set the timing.  Unless, of  
course, you simply put the Corvair on the dyno and use the results to change the 
 MegaSquirt settings you start with.  But how do you change factory  
settings of production ECM units that are designed to work with NARROW-band  O2 
sensors that try to run the engine at stoichiometric A/F and timing that is  
set for combustion chambers much different from Corvairs??
 
Frank "old dog trying to learn new tricks" Burkhard
 
 
 
In a message dated 10/11/2010 2:16:14 P.M. Eastern Daylight Time,  
62vair at gmail.com writes:

Thanks  Frank, its actually Charlie who is the receiver here. I've already 
am
about  half way through my EFI project. And, I've already been on the DIY 
EFI
site  quite a bit. Rather than building my own board, I bought a rebuilt
1223370  GM 90-92 Camaro stick ECM and chip for $50. I just finished my
wiring  harnesses for the ecm (3 of them) and have acquired most of the
parts. I'm  modifying the carbs to straight throttle bodies boring out the
venturi and  ecpanding the bore to 1.33", will make a new set of throttle
plates for it.  Have all the sensors, etc. Just waiting for bad weather to
bring the car  inside (I still want to drive it on sunny days) and the
conversion will  begin!
Mark Durham

On Mon, Oct 11, 2010 at 10:16 AM,  <FrankCB at aol.com> wrote:

>  Mark,
>
> A good  idea to get started with this is to go to    www.diyautotune.com
> and click on the "Tech Articles" button to access  a number of detailed 
(with
> pics) articles.  The first is a  conversion of a carbureted Chevy V-8 to
> throttle body EFI.   Others cover multiport EFI. Whether you use the
> MegaSquirt or go to an  EFI from a production car, these articles will 
give
> you a lot of  insight into what's needed and how to go about it,
>  step-by-step.
>
> Incidentally, you can build your MegaSquirt from  a kit of parts OR buy 
one
> already assembled.  If you build it  yourself, I recommend getting a
> Illuminated magnifying glass light as  well as a temp. controlled 
soldering
> iron with a VERY small tip.   If you don't have experience soldering micro
> circuit boards, I suggest  buying the already assembled unit.
>
> Frank  Burkhard