Re: Memcals

["Bruce Plecan" <nacelp@bright.net>]

Memcal. is used on P-4, and some later ecms.  It holds the prom, and then at
least one netres (gmese, for resistor network).  Some have two netres, and a
printed circuit board.  The second netres, and circuit board are for knock
filtering.
  The first netres holds the limp home mode "calibration".
Usually starting with a "close as possible" memcal will get at least a
drivable car in limp home mode.  Results vary, by engine mods..
Grumpy
   In round MYs, 88-95 will yeild memcal ecms.   This has exceptions, but
just as a time pointer.   If you go to syty. page they have some neat info.,
piccs of what they look like.

| for us newbies out here-- what exactly
| is
| a MEMCAL-- a hard wired chip or are they
| programmed chips? If they are hard wired
| - are they resistor/capacitor (analog?)
| wiring? the reason I am asking -- if a
| car is modified ( cam and headers) will
| the memcal be able to provide a limp
| home mode. if not is there a
| resistor/capacitor combo in one that
| would adjust the base fuel amount so
| that limp home mode would work? The
| assumption I am making is that they are
| hardwired resistor/capacitor
| (differentiator and integrator)
| circuits.
| I read the gmecm archives but could only
| find a lot of assumptions.. no real hard
| info.
| yea well...(curiosity killed the cat)
|
| byE
| Mike S.
|
| JTesta1966@aol.com wrote:
| >
| > In a message dated 1/14/00 7:02:42 AM Eastern Standard Time,
| > gerich@one.net.au writes:
| >
| > << List
| >  I was reading through a memcal application chart and found different
memcals
| >  for the same vehicle depending on whether heated or non-heated o2
sensors
| >  were used.
| >   >>
| >
| > Probably something to do w/closed loop timer....stuff like that. My GN's
| > original chip had one timer, the recall chip for the same car is like
2/3 of
| > the time, and the coolant temp to enable closed loop was changed as
well.
| > Other that that there wasnt much different that I recall. Most likely
| > something like that in your case.
| >
| > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| > Jim Testa                                         TType86 on #BuickGN
| > jtesta1966@aol.com                               buick.fiendish.net:6667
| > ASE Master Technician            NJ Lic. Motor Vehicle Inspector
| > L1 Adv Eng Perf Certified     NJ Licensed Emissions repair Tech
|