Engine swap computer & wiring question

[Tim De Coster]

Hey Shanen, it's good to hear from you again.. it's been a while.  I'm glad
I didn't buy the EPROM from the '91 Z for no reason.. but to use it I would
have to get the ECM too... and decide on the 3400.  Not sure what to do here
yet.

Like you pointed out, SFI doesn't do much for performance, so I don't care
much about that anyway.

You scare me a little when you say I need to get big time into programming
this thing.  I really have no experience in doing this.  I don't really
think that using the 2.8/3.1 intake, etc. will be a good thing to do either.
That's really all that separates a 3100 from the 3.1, and thus more HP, of
course the CR is thrown into the mix too.  I already have bought a shop
manual for the '88 Sunbird, and for a '88 Cimarron for in case I go that
route.  Plus the ones for my '89 Z, and '88 Z electrical, so I have enough
resources to get started at least.. now I just need the time.

Wow, I didn't realize you had a '88 Sunbird 2.0 conv. too!  Did you get that
in the last year or so?  I just started driving mine again last week... new
paint... CLOTH roof (no vinyl for me anymore).. and best of all... a rear
glass window!

Tim De Coster
'89 Z24 Conv.
'88 Sunbird GT Conv.
'98 Intrepid
www.sunbirdconvertible.com
----- Original Message -----
From: "Shannen Durphey" <shannen at grolen.com>
To: <gmecm at diy-efi.org>
Sent: Thursday, July 13, 2000 6:08 AM
Subject: Re: Engine swap computer & wiring question


> I shoulda recognized your name right away.
>
> Well, I'd use the ecm from the 91 Z.  The number on it is probably
> 1227730.  It's used in Camaro's with 8 cyls, and lotsa 6 cyl cars, so
> lots of 'em around.  Sunbird VSS for regular dash is cable driven in
> 88.  I know, mine bounces on cold mornings.  Makes 2000 pulses per
> mile. If the Z's have a non- digital dash , it will be the same
> sensor.  4 cyl ecm is different, further it's different for
> chev/pontiac engine, early or late turbo, tbi or pfi engine.
> Basically, toss it.  SFI is extra work, nice to say you've got it but
> not a key element in winning a race.  "SFI= more power" is not the
> whole story with factory engines.  You _need_ to get reliable wiring
> diagrams for your car and engine, and another one for the z24 that
> your "chip" is from.
> Using the old chip:  There are lots of updates to the proms.  What are
> the four letters/numbers on the chip (like ARUN/9039)?  I can see if
> it's a current version.  Some of the driveability bugs that the
> updated proms fix are buggers to live with.
>
> Unless you like a serious challenge, forget the OBDII idea.  If you
> just want the car to run, you might be able to fudge a stock 3.1
> calibration, play with fuel pressure, and make it go.  To get the
> most, better decide now to get into reprogramming it yourself.
> Anybody who's serious about performance should be into tuning their
> own cars.  Few "generic" chips that I've seen are really good, and
> some are pure BS, IMO.  A side benefit is that you'll have enough
> experience after tuning the 3.4 to start tuning your buddies' cars.
>
> I would also seriously consider using a set of 3.1L heads and intake
> if possible.  Most of the "wowie" for the 3100 and 3400 were in these
> parts, and yes you would be tossing that.  The tradeoff would be
> getting an intake and heads that will support all the
> brackets/ducts/hoses that are already in the J cars.  Trust me, in an
> engine swap the smallest problems can easily become big, expensive
> headaches.  If you've got good fabrication skills and tools then you
> can figure those headaches out on your own.  But if you're into your
> first swap it's better to play it safe.  Once the engine swap bug
> bites, you'll get plenty of "do overs".
>
> First step, IMO, get the wiring diagrams and start making
> comparisons.  Make plenty of trips to the junkyards, too.
> Shannen Durphey
>
> 57 Chevy pickup, 302 Crossfire
> 67 Chevelle, LT4 copy, pfi'd next week
> 79 Monte Carlo, 455 Buick and rust
> 86 Toyota 4X4, more diamond plate than one man should own
> 88 Sunbird Convertible 2.0
> 93 Cavalier 2.2
> And they're all due for oil changes!

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