[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Engine swap computer & wiring question



Was testing a 2000 Mexican GM truck chassis auto.
transmission with US engine and parts of a Romanian SUV
body  in Feb. for federal certs.  Were in a big rush and and
customer could not hook up transmission electronics.  On
dyno driver is instructed to stay on driver trace no matter
what.  I heard a very high reving engine at 56 mph and saw
the exhaust system cherry red to the rear muffler and
interior starting to smoke, so aborted test.  Transmission
was in drive but never got out of 1st.  Must of also entered
a rich default mode since engine sounded strong and sweet
and had high modal emissions.
Alex
----- Original Message -----
From: Bruce Plecan <nacelp@bright.net>
To: <gmecm@diy-efi.org>
Sent: Wednesday, July 12, 2000 2:08 PM
Subject: Re: Engine swap computer & wiring question


> Subject: Re: Engine swap computer & wiring question
>
> Somethings to look at:
> The 96 uses a pcm.
> They control the powertrain not just the engine, as in
tranny shifting,  do
> you think the oem tranny is going to last with this new
engine?.
> I'd think about going engine and tranny,  then just use
the harness as a
> whole,
> For the dash end of it ya need to get the manuals and see
what hooks to who,
> and then what signals they are to see if they are the
same.
> If you go to a manual tranny was that an option with that
engine?.  If not
> you might spend some serious time getting things running
right.
> Any thing is possible, just some things not practical.
> Man gotta know his limits, and then work on em.  ie, get
all thenfo you can
> (like your doing, but gotta dig for as much as ya can)
> Grumpy
>
>
> > Steve,
> > Thanks for the tips.  Man, that Blazer must fly!  The
reason this swap may
> > get a little bit hairy is because I don't think I'll be
able to use the
> > entire harness out of the donor car because it will be
an OBDII computer,
> > and from what I understand, it's not easy to get a OBDII
computer to
> > function in an older car.  So do you think that my
existing computer could
> > control this new engine if I get a new EPROM module for
it?  I already
> have
> > one from a '91 Z24 (It had a 3.1 v6), and I am hoping
that it will work.
> It
> > may because the 3.4 is basically the same exact engine
as the 2.8, except
> it
> > has revised heads, among a few other things.
> >
> > I know that the Cadillac Cimarron's digital dash does
talk to the ECM,
> > because I was going to put the Cimarron digital dash
into my Sunbird...
> > until I found that most of the info. for the gauges goes
through the ECM
> > before it gets to the dash.  This probably would mean
that the Cimarron
> > wiring idea is out of consideration, right?  The only
reason I thought of
> it
> > was because the dash is physically the same in it, and
it has a 2.8 mpfi
> v6
> > engine.
> >
> > I'm not sure exactly where the vss signal comes from in
the Sunbird, I'm
> > still working on getting a GM manual for this car.  I
know that the
> digital
> > dash in my Z24 does, but that's a different application.
> >
> > Thanks again,
> > Tim De Coster
> > '89 Z24 Conv.
> > '88 Sunbird GT Conv.
> > '98 Intrepid
> > www.sunbirdconvertible.com
> >
> >
> > ----- Original Message -----
> > From: "steve ravet" <sravet@arm.com>
> > To: <gmecm@diy-efi.org>
> > Sent: Wednesday, July 12, 2000 12:31 PM
> > Subject: Re: Engine swap computer & wiring question
> >
> >
> > > Tim, I'm not familiar with those models, but I have
been through an
> > > engine swap (replace 2.8L w/ 5.7L in my Blazer).  What
is the concern
> > > with the dash?  Is it electronic, and wants to talk to
the ECM to get
> > > MPG info or something?  If not then I don't think it
matters too much.
> > >
> > > I'll talk about my swap some, it's probably similar to
what you'll
> > > find.  There are two places where wires cross from the
engine
> > > compartment to the inside of the vehicle.  One is the
ECM harness, which
> > > runs from the engine thru a hole in the firewall to
the ECM behind the
> > > dash.  This bit of wiring is almost completely
isolated from dash/body
> > > wiring.  Exceptions that I can recall are ALDL signals
like data, TCC,
> > > etc. that have to run over to the ALDL connector.  VSS
also comes from
> > > the dash in my app, not sure about yours.  Anyway, as
long as you use
> > > the ECM that comes with the engine there is no problem
here, just splice
> > > in the handful of wires for ALDL/whatever and the rest
plugs right up.
> > >
> > > The other connector is the bulkhead connector.  The
car side is anchored
> > > to the firewall, the engine side comes from the engine
bay.  When you
> > > get your new engine it'll have it's own bulkhead
connector, and there is
> > > basically no chance that it will plug directly into
the existing car
> > > half of the plug.  Wires and signals here can be
different even on the
> > > same year model cars, depending on options etc.
Fortunately there is
> > > little/no engine wiring through here.  Typical things
here are wiper
> > > controls, A/C controls, power to and from fuse box,
engine sensors that
> > > go to dash gauges (but NOT ECM sensors, they are in
the ECM harness),
> > > etc.
> > >
> > > What you'll have to do is go to the junkyard and buy
an engine side
> > > bulkhead connector that is physically the same as
yours (from the same
> > > model car), and all the wires attached to it as long
as possible.
> > > You'll cut off the bulkhead connector from the new
engine, and connect
> > > the wires to the appropriate places on the junkyard
bulkhead connector.
> > > Use crimps, and then solder them, like the service
manual shows.  The
> > > junkyard connector may have blank places in it where
yours has wires, in
> > > that case you'll have to add pins and wires.  You
could re-use your
> > > current bulkhead connector but I wanted to leave the
old engine as
> > > intact as possible so I could sell it.
> > >
> > > You'll need a service manual/schematics for both the
donor engine and
> > > your car to properly match these up.  I spent probably
20 hours or more
> > > sitting in front of the computer, going over the
schematics, typing in
> > > what went where, and double/triple checking all of it.
Then I printed
> > > it out and started cutting and twisting wires
together.  I wrapped all
> > > the twists with bright green electrical tape.  Lots of
time but I had no
> > > wiring errors to track down later.  Once it's working,
take off all that
> > > green tape, crimp and solder the wires properly, put
them back in the
> > > loom, tape it up nice, and off you go.
> > >
> > > All bets are off if the dash wants to talk to the ECM
via ALDL, though,
> > > like the digital dash vettes did.  hope yours isn't
like that.
> > >
> > > You'll make the swap easier if you get the new engine
intact with all
> > > it's wiring, accessories, sensors, etc.
> > >
> > > write back if you have more questions.
> > >
> > > --steve
> > >
> > > Tim De Coster wrote:
> > > >
> > > > Hello,
> > > >
> > > > I'm new to this list, and have to admit that much of
what goes on here
> > is a
> > > > little over my head.  I do however, have some advice
to ask for.
> > > >
> > > > I have an '88 Sunbird GT with a 2.0 OHC non-turbo
engine and am
> > eventually
> > > > going to install one of the '96+ 3400 OHV v6's.  My
question is:  what
> > is
> > > > the best way to handle the wiring and computer
change-over?
> > > >
> > > > Ways I have thought of:
> > > >
> > > > Getting the complete dash wiring and engine wiring
from an '87 or '88
> > > > Cadillac Cimarron (it had the same style dash and a
2.8 mpfi v6
> engine).
> > > > This way I would have the v6 wiring that I need,
though the computer
> > will be
> > > > programmed for the 2.8.  I think it would work, but
I'm not sure in
> > > > real-life what sacrifices would have to be mad going
this route.  I'm
> > sure
> > > > that I would have to run the engine in MPFI mode
like the 2.8 is,
> unlike
> > the
> > > > SFI mode that the 3400 was built for.
> > > >
> > > > Another idea was to use the existing dash wiring and
computer that is
> > > > currently in my Sunbird and getting the wiring out
of a '91+ Chevy Z24
> > that
> > > > had the 3.1 v6.  I would then have to change the
EPROM, but I'm not
> sure
> > if
> > > > the engine wiring will plug right into the existing
harness and
> > computer.  I
> > > > think the computer itself is the same, but this
isn't confirmed.
> > > >
> > > > Getting a computer for the '96+ GM minivans or other
GM vehicles the
> > 3400
> > > > came with is probably out of question because they
use the OBDII
> > computers
> > > > which I understand are a pain as far as engine swaps
are concerned.
> > > >
> > > > Any comments or suggestions on this would be VERY
appreciated!
> > > > If you're interested, check out my website listed
below.
> > > >
> > > > Thanks in advance,
> > > > Tim De Coster
> > > > '89 Z24 Conv.
> > > > '88 Sunbird GT Conv.
> > > > '98 Intrepid
> > > > www.sunbirdconvertible.com
> > > > www.z24convertible.com
> > > >
> > >
> >
>
> ----------------------------------------------------------
----------------
> > --
> > > > To unsubscribe from gmecm, send "unsubscribe gmecm"
(without the
> quotes)
> > > > in the body of a message (not the subject) to
> > majordomo@lists.diy-efi.org
> > >
> > > --
> > > Steve Ravet
> > > steve.ravet@arm.com
> > > ARM,Inc.
> > > www.arm.com
> >
>
> ----------------------------------------------------------
----------------
> > --
> > > To unsubscribe from gmecm, send "unsubscribe gmecm"
(without the quotes)
> > > in the body of a message (not the subject) to
> majordomo@lists.diy-efi.org
> > >
> > >
> >
>
> ----------------------------------------------------------
----------------
> --
> > To unsubscribe from gmecm, send "unsubscribe gmecm"
(without the quotes)
> > in the body of a message (not the subject) to
majordomo@lists.diy-efi.org
> >
>
> ----------------------------------------------------------
------------------
> To unsubscribe from gmecm, send "unsubscribe gmecm"
(without the quotes)
> in the body of a message (not the subject) to
majordomo@lists.diy-efi.org
>



----------------------------------------------------------------------------
To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
in the body of a message (not the subject) to majordomo@lists.diy-efi.org