Bosch/Buick crossbreed

[Dave Williams]

 I've made some progress on my EFI transplant.  I have a '79 Buick 3.8
V6 going into my '84 Mazda pickup.  The engine was, of course,
carbureted in its original form.  I acquired an '82 Toyota Celica Supra
EFI setup for free, though it took almost three days to extract the
harness and bits from the Toyota.  The Supra's EFI is a Bosch L-Jetronic
made under license to Nippon Denso.

 The first order of the day was to acquire a Buick EFI intake manifold.
I managed to snag one, complete with rail, injectors, and regulator, for
$20.  The runners are visibly smaller than the ports in the heads, and
quite short, shorter than some tunnel ram intakes I've seen.  The
manifold is off an FWD car, so the throttle body will point back toward
the firewall in my application.  I will have to use an elbow to turn the
air path to get to the air filter.

 Oddly enough, the Supra's throttle body was about 3mm larger in
diameter than the hole in the Buick intake.  I whittled a 3/8" aluminum
adapter plate on the milling machine and drill press.  Since the
throttle body's linkage fouled the water neck (which is at the back of
the intake, as I'm using it) I flipped the throttle body upside down.
It will mean a little more work with the throttle linkage, but it fits a
lot better that way.

 The Buick fuel rail has a Bosch part number, and the Buick fuel
pressure regulator says "Bosch" right on it.  Hmm, I thought all that
stuff would be Rochester.  The regulator fouled the throttle linkage,
which I'd already flipped to avoid fouling the water outlet.  Dang.  I
sawed the regulator off just past the last injector boss.  The Supra's
regulator setup looked different, but worked the same way as the Buick
one, except instead of being attached to the rail itself, it is fed
through a line that attaches to the rail with a banjo bolt.  I sawed the
threaded boss off the Supra's fuel rail.  The OD of the Buick rail is
close to 3/4"; a nice side cut on the Supra's banjo boss with a 3/4" end
mill and it will be close enough.

 Looking at the Buick rail, I can't tell if it's welded, brazed, or
soldered together.  I'll be attaching the threaded boss to a ~4" long
space between the last two injectors; the plan is to braze it in place.
I'm kind of leery about soldering something like that.

 The Supra's injectors are odd - the ends are longer and smaller in
diameter than 'normal' Bendix type injectors.  They should work with the
proper O-rings - I will be checking on those later.

 The Buick was SEFI.  The L-Jetronic is batch, three at a time.  Ford
5.0 SEFI fuel tails are no more than 3/8"; the Buick rails are enormous
by comparison at 3/4".  I have a Bosch "pulsator" around somewhere, I'll
probably plumb that in.  Bosch puts them on the feed side, between the
rail and the pump.

 After finishing up the fuel rail, I get to make some metric to NPT
bushings to mount the Bosch water temp senders, etc.  Then I get to
untape the wiring harness and carefully extract all the EFI bits from
the rest.

 Hartman says in his EFI book that the L-Jet will recognize the spark
signal from a GM HEI.  Shouldn't be too long before I bench test the
thing.

==dave.williams at chaos.lrk.ar.us======================================
I've got a secret / I've been hiding / under my skin / | Who are you?
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