Programming 101

[Bruce Plecan]

Well if you have missed any of the prior postings on this I would
recommend you read the archives, and catch up with this subject.
Again, this is for educational purposes, and should only be done
with adult supervision.  Changes can lead to engine damage,
loss of performance, and increased emissions.  Any experiments
with this subject manner should be for off-road use.

  In a great number of gm ecms there is what is called Power
Enrichment, commonly called PE.  There are numerous conditions
that must be meet for it to be enabled.  The trigger (if you will) is
a percentage of TPS.  Based on rpm once this theshold is
exceeded it puts the ecm into PE, and the O2 sensor is ignored,
and the engine answers the helm with a max effort.  Now. there
seems to be several opinions on how the ecm executes the
mixture for this.  One train of though is that the ecm basiclly goes
open loop.  Next is that the ecm applies a correction to the WOT
mixture from the block lean correction.  The third view is that the
ecm applies only a correction of richness from the BL correction.  IMHE,
it's one of the later two.  It also appears to vary from
application to application. If you follow the tune-up procedures from my
earlier postings it is really a mute point.  The percent of TPS to enable PE
appears to be at 047D-0485.
  We covered the WOT spark adder, so now we must look for a
WOT Air/Fuel Ratio.  That would be at 0487-048E..
  Hmm, maybe next we'll talk abit about the math used in some
of the tables settings we've found.
  Again I invite any and all to contribute any information they might
have about tables, enables, switchs, and there addresses.
  No worries mate
Bruce    Again when refering to this text please edit the rely.
              nacelp at bright.net