Re: Technical Questions

["Andrew K. Mattei" <amattei@mindspring.com>]

Hey Guys, here's one that should be straightforward if you know the answer.
Unfortunately I don't. ;^) Can anyone help this guy? Sounds like a cool
project, he just needs a small push to finish it up.

Thanks,

Andrew

-----Original Message-----
From: K.E. Towle <karljiml@compuserve.com>
To: amattei@mindspring.com <amattei@mindspring.com>
Date: Wednesday, June 28, 2000 12:07 AM
Subject: Technical Questions


Sir,

I just found your site, and I'm very glad to have the information on line.
Thanks! If you can find the time to answer the following questions, it
would sure be appreciated.

Here is the situation. We are in the final stages of an engine/transmission
swap. The vehicle is an 85 Cadillac Cimarron, and we have installed the
2.8L engine/transmission out of an 88 Beretta. The installation went well,
and we have worked out the wiring issues, to the point where the engine/ECM
work fine with the 85 car. The major complication was the digital
instrument cluster. We found that the Beretta ECM wouldn't talk to the
cluster (as you probably know; temp, volts & RPM are sent by the ECM to the
cluster over the serial data link), and in the process, we learned that
Yazaki made two different digital clusters, one for the 85/86 Cimarron
(white case, p/n 25081527) and another for the 87/88 Cimarron (blue case,
p/n 25083444). It looks like I now know that these correspond to the C3 and
P4 series of ECMs respectively with their different serial data rates and
formats. Anyway, after several unsuccessful attempts, I finally ended up
with a digital cluster AND ECM (#1227730) from an 87 Cimarron (2.8L) and
finally, the dash displays the missing data. However, the problem now is
that the 87 Cimarron ECM did NOT have the speed density modification, and
the 88 Beretta engine I started with did. Since I liked the way the engine
ran with the speed density mod, and I've been advised to try to keep it, I
am now faced with attempting to locate a mem-cal from/for an 87/88
Cimarron, with digital dash, and speed density. Here is what I have now:

ECM Info: Svc #1227730 AAWU 865261 M612491005 (From wrecked 87 Cimarron)
Cal-Pack: 1A7307  ADRY 2642
  Bar Code inside ECM: 142089108276245 (NOT speed density)

The dealer's listing is confusing; he says he shows the same numbers for a
Cal-pack, with a note saying "use with speed density kit," The problem, is
that this Cal-pack is clearly NOT a speed density type. When I configured
my scanner for 'speed density = yes,' the data returned and displayed made
no sense at all, and it displayed a code 41: cylinder select error. When I
reconfigured for 'speed density = no,' the data made sense, and the code
reported was 34 MAF low frequency, which would be right for a SD modified
engine.

So, my questions are as follows:
1. Is it possible to replace just the eprom on the cal-pack, and if so,
how? (I didn't want to ruin a good one experimenting)
2. I understand the 1227730 ECM uses a 27C256 EPROM. I have EPROM
programming capability, do you know where/how I could download the data for
the correct EPROM for an 87/88 Cad Cimarron, 2.8L, digital dash, speed
density modified?
3. What functions are performed by the resistor pack on the Cal-Pack, and
are they all as different as the variations in numbers would seem to
indicate?
4. What are the 14 and 16 pin DIP ICs mounted under the resistor pack, what
are their function(s), and do these two parts differ between Cal-Packs?

I would truly appreciate any answers you can supply to the above questions,
and or additional insights you can give. We are trying to finish this
project, and it looks like it can be done, once I obtain the correct
firmware. Thanks again for your web site, and help.

Sincerely,
Karl Towle
SouthWest AutoMotive

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