why the big difference in ECUs?

[Romans, Mark]

There is more to it than this.  (I'm not saying that the ecu's aren't
different, I don't know) it's probably the code.
I have a friend who has an 89 TA GTA that he installed a 6 speed in.  (He
also has a vortech)
When he installed the 6 speed he started having a problem with the idle
speed flaring on hot start and
hanging for a while at about 1800 rpm's. I tried an 89 305 5 speed bin and
it resolved the hot start problem,
but obviously wasn't right for the350. I tried to apply all the settings
from the fully dialed 89 Auto Trans 350
to the 305 bin.  All the fuel settings, spark, injector constants.
Basically every setting available in the latest
version of GMe.
Then I did a file compare.  About 11,000 differences out of 16,384!!!!!!
Turns out the whole fuel strategy is different.  The 305 was set to single
fire for starters.  I finally took about 60
iac control settings and plugged them into the 350 bin.  Seems to have
reduced if not eliminated the problem!
On second thought, it's probably not the ecm, it is differences in the bin
file from one year to another that
may not show up in the tuner.
Mark
----- Original Message -----
From: <KasaRyan at aol.com>
To: <gmecm at diy-efi.org>
Sent: Sunday, September 10, 2000 12:15 PM
Subject: why the big difference in ECUs?


> Ok. I had a pretty good bin set up for the 94 7427 ecu in my truck.  I
> thought I would use tunercat and take all the table values and duplicate
it
> for the 93 8625 ecu that goes in the truck.  I opened the stock 93 bin up
and
> set to changing table values, saved it, burned it, ran it.  The only
things
> that worked right were idle and wot.  It bucked and jerked and wouldnt run
> right and was not very friendly - a digital throttle.  It didnt get any
> better or worse when it went into closed loop.  Yesterday I took the 93
bin
> and modified the injector size only and tried to run it.  It ran like
crap,
> so I decided to change all the table values.  It still runs like crap, but
in
> a slightly different way.  When I originally got my howell setup, they
made
> me buy a 94 7427, because Troy said they couldnt work with a 93.  There
must
> be some truth to this.  Obviously there is some sort of damping factor
value
> somewhere in the Howell bin that lets this combo work that is not in the
> factory bin.  Either way I can't get to it with tunercat.
>
> Does anyone have any ideas of what is wrong - I can zap you my bins.
>
> Thanks for listening to my electroyappin!
> Ryan Hampl - a K-State Grad!    kasaryan at aol.com
> 139 Hoover Ct.                  Controls Engineer (tubes rule!)
> Salina, KS  67401               97 B12 / 86 V65 / 93chevy truck EFI 383
> phone  (785) 825 5831           I'M ALWAYS FIRST TO THE GROCERY STORE!
> --------------------------------------------------------------------------
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