[alfa] Random EFI idea

["Peter Webb" <webb.p@xxxxxxxxxxx>]

Had a random idea, not totally formulated yet.  I wanted to gauge the
interest before I think on it too much.

As many know, I have the MegaSquirt working well in the Verde and about to
finish the Spider.   There was much interest in this project to replace the
L-Jetronic system.

So, at the convention next summer, how about a MegaSquirt installation
session?

I would build some units and bring them with me, along with the appropriate
vacuum lines, TPS, documentation and tuning software.    You would need some
mechanical ability, some understanding of EFI and a laptop computer with
serial port and cable.    I'd charge $100 over the cost of parts for my time
to build them.   One unit takes about 3-4 hours to build and test so it's
not a lot.

Approximate costs would be:

MegaSquirt parts:     $130
MegaSquirt Assembly:  $100
Vacuum tubing:        $2
TPS:                  $70
TPS adapter:          $50

Something like getting together in a parking lot (or workshop if there's one
available) in a tech session sort of format with everyone doing their own
installations.   The installation into the car should take about 2-3 hours
on the slow side.  Maybe only an hour for more experienced mechanics.  No
permanent modifications of you car is required.   The wiring harness will
not be damaged.   The stock sensors will be retained.   However, if you
wanted to remove the AFM you'd need to get a GM IAT sensor (available from
any auto parts store for $25) and insert it in the plenum and wire it to the
AFM connector plug.    The goal that day would be to get it running with the
stock sensors, leaving the AFM in place as a basic running installation.
We can talk about modifications but there's really no time to go through
everyone's individual requirements.

This would apply to owners of GTV6, Milano, 82-89 Spiders.   It can be done
on the 164 M1.7 and Spider M4.1 Motronic but it's a little more difficult.
I'm not sure I want to tackle a Motronic replacement yet.  I have tested on
my own L-Jet Spider and V6 so I know it works.   I'll have base fueling maps
for download and show you how to work out your specific tuning issues along
with a copy of the MegaSquirt manual that covers all of this.  I'll also
have some custom code to control the VVT if you want, but this is a great
opportunity to lose the VVT and tune some performance cams with the fueling
to get performance and still pass emissions without the VVT.

The MegaSquirt has a designed aluminium case and uses a DB37 to interface to
the sensors.   I've possibly found a source of the L-Jet 35 pin connectors
to make an DB37->LJ35 interface cable instead of building into the L-Jet
case.   If someone had a preference one way or the other, I could build into
the L-Jet case for them like I did mine.   The plan now is to put  the MS in
the L-Jet case in the Spider and build a another for the Verde using the
cable.   Since the hardware is common, all you have to do to switch cars is
plug it in and download the tables (and software if there are changes) and
go.

Since many of you are techies, we can talk a little about MC68 assembler
code that controls the fueling.   99% of you won't need code mods, just
table tuning, a simple laptop screen.  1% of you are crazy like me and start
modifications that need extra code that require some programming skills and
a basic understanding of assembly language.

So any ideas or willing participants?

-Peter

Apologies to our non-US friends for the country specific content.   Though
most of you were lucky enough not to get L-Jetronic on your car to need
replacing in the first place.
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