749 in a 730 - troubles

[Ludis Langens]

CSH-HQ wrote:
> 
> What ecm in 93?.
> If not 730 for forget it

93 J-car 3.1 uses a 730.

Jeremy Gonyou wrote:
> 
> Searching the archives, I found a lot of talk about putting the Syclone bins
> in 730's.  Having a 93 sunbird with a 3.1, I decided to go ahead and try
> it(after some quick modifications with promgrammer).

I haven't quite figured out what the second interface chip (34984 or
79435) in a 749 does.  It for certain runs the second P+H injector
driver.  But it has been reported that the SyTy doesn't use that
feature.  The 2nd chip might provide an extra input port or peripheral control.

Perhaps the SyTy code expects the functionality of this extra chip, and
gets confused when it is missing.  That might be why 730 chips work in a
749, but not the other way around.  (730's are missing the 2nd chip.)

> The car runs pretty well, actually, but the ses light is on and it won't
> give me code.  Also, the speedometer won't work.

Sounds like the chip/CPU is totally out to lunch and you're running in
limp home mode.  Did you verify your programming of the EPROM?  And that
there are no bent pins and so on?

> Also, the speedometer won't work.  Do I have to set a byte
> for the type of speed sensor I have?

Yes.  That's a known byte(s) in the SyTy, so promgrammer ought to know
how to set it.

-- 
Ludis Langens                               ludis (at) cruzers (dot) com
Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/