[Gmecm] Hmm, interesting...
botboy60 at hotmail.com
Tue Mar 29 00:41:26 CST 2005
Ok so I'm getting better at tuning some basic things on my '72
Cheyenne/350/454 TBI/350 injectors with a 7747 & moates G2.
Anyway, I started out with an ASKM broadcast code chip, which is for a
4.3L/auto vehicle, which made the truck run at least better than the couple
of 350 broadcast code chips I had lying around when I first did the swap and
didn't have any programming tools.
So I did a few changes on my 2nd to last chip, including upping some
sections of the adder VE table and disabling EGR and changing the IAC park
position on the advice of another member of this mailing list. With this
chip the truck idled reasonably well at a stable RPM and was at least better
accelerating cold than it was before with the unmodified ASKM chip.
So on my last chip, I dropped the ALDL/Closed loop spark from 8.086 to 000,
and realized that the cylinder select was still at "6" and not "8".
When I tried running this chip cold, the idle was way worse than before, and
seemed to be "hunting" between about 500 and 1100 RPM, and would eventually
die out after hunting kept dropping the RPM's lower and lower. As I
understand it the ALDL/closed loop spark variable is only brought into play
when a scanner is hooked up or pins A&B are bridged (which wasn't the case)
so changing the cylinder select from 6 to 8 is exclusively responsible for
The only thing I can think of is that this modified the injector firing
ratio in async firing mode, but my curiousity is how I can correct this so
that I can have the cylinder select at 8 and keep my idle at least
relatively normal. Any ideas?
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