New to list, have a question.

[cloud at peaches.ph.utexas.edu]

At 01:43 PM 3/6/99 -0600, esc <esc at firstnethou.com> wrote:
>>Eric,  I also have an early ProJection  ....  doesn't have the EGO

  ..... snip

>The main problem I have with the Closed loop kit has to do with how it
>modifies the TPS voltage.  Generally the baseline mixture is too rich so it
>leans it out.   If it(closed loop kit) leans the mixture very much then
>when you give a little more throttle it gets very lean and does not
>accelerate properly.  This kit does not function above 2/3 throttle, so I
>find myself often applying a lot more throttle than would otherwise be
>needed just to avoid the closed-loop-kit-induced flat spot.

 1 . my setup, without the EGO feedback, goes very lean at the slightest
increase of the throttle from cruise. Best I can figure is the slight
opening of the throttle plate adds enough extra air to make it lean
but the tps voltage increase isn't adequate to be sensed as an increase
in fuel ????

 2 . the 2/3 throttle thing is probably just a voltage divider somewhere,
should one want to modify it

 3 . are you aware that I have made a parts list for the 502 (or is
a 520 ??) and a PCB drawing for it ??  Someone has a web site for
the Holley ProJection (lemme look .....  yeah, check with
Andy <mpc at genevaonline.com>.  He had the stuff I did on that site. Dunno
if he still has it or not. If you want what I have on the ProJection,
holler and I'll send it to you

>>  . then, consider that a MAP input might be more logical ??   I had
>>entertained the idea of either building my own ego feedback unit or
>>a map feedback unit -- or could actually sum the two together ??  All
>>that's needed is to sum the input from the tps with the conditioned
>>voltage(s) from the other devices.  To me, the map input makes more
>>sense and would elevate the unit from the status of simple alpha-n
>>controller to a simple speed-density unit (which their literature
>>claims it is anyway!).
>>
>
>
>I agree that a MAP input is what I need.  Without it the Ram-air system
>will always be troublesome.
>The problem is how do I do it?
>
>I really like the throttle body part of the ProJection, but thats the only
>part I really want to keep.  I'm not all that happy with the controller.  I
>really want something that I can have more control over and that will
>accept input from more sources.
>
>Eric

You are in the right place, IMO  ....  there's several who have
adapted the GM ECM to the ProJection TB.  "Bruce Plecan" <nacelp at bright.net>,
who is on this list, is probably your best contact, IMO.


Tom Cloud <cloud at peaches.ph.utexas.edu>