LA2 and LA3
cars it is
wise to add the stock location intercoolers from an SVO™ or Turbo
Coupe™, or go all out with a front mount. This will
assist in fending of
detonation due to fuel table and timing differences that take the
cooler intake temps into consideration. It is recommended to move all
pins even if you plan to use aftermarket boost controllers or you are
swapping to a car that does not have the regular/premium switch. This
part of the process only takes about 20 minutes depending on how hard
it is to get the ECU out and back in to the inner fender. For turbo
GT's you will need a big VAM. You will also need to run 35# low
impedance injectors or as a temp solution up you fuel pressure to 43
PSI. You may want to go a bit farther and swap for a later upper and
lower intake, but that is much more involved depending on the head in
the car and is beyond the scope of this write-up. The instructions
below are SVO specific, but with the changes mentioned is easily
adapted to the earlier turbo cars.
I used the
svo1fast4's web site. His site is back up and I must appologise for
taking so long to activate the link. Please take a few minutes to check
out his web
where you will find 4 other very helpful how-to articles and much much
I made only
adjustment during my own install; moving the octane switch wire before
the last two due to this being the most buried of the wires. I have
included a pin chart for the stock 86 SVO harness from GT350R's web
site, of which I used only the plug diagram to make sure I was in the
right place. My SVO™ ECU plug was not numbered at all! It's not
to tell where things are, as there is only one white wire with a black
line 3 spots from the outer rows, so use that wire to get oriented and
you'll be on your way. You can't really mess this up, but recheck your
work after all the lines have been relocated and test the ECU before
you bolt it back in.
Open your hood and unhook the battery positive cable. On the passenger
side front, Remove the first screw in the
carpet hold down trim and pull off kick
panel. Get out
your 7mm socket and extension
and remove the plastic
bracket hold down
bolt. Get out your 10mm socket and loosen the ECU harness plug bolt.
This bolt does not come out of the plug. Pull the harness plug and
other wires out of the way and remove the old ECU.
black wire guard.
Flip the plug toward you and pull the red locking tab out. I used a
Allen wrench inserted into one of the unused holes and gently pulled it
to the side to slide the locking tab free. The wires are in there
pretty good, so they won't all pop free when you do this (I hope).
I used the
to push on the pins that needed to be changed, to work the wires free.
Once they are loose, then
you can pull them out from the back; some are in there really tight so
this method means less of a risk in ripping the wire free from the
Now you are ready to begin
the wire swapping.
Vane air temperature:
wire 43, white wire with a black stripe and move it into pin slot 27
Vane Air Flow sensor:
wire 25, light green wire with a purple stripe, and move it to pin slot
30, yellow with red stripe, and move to pin #24
Boost controller (BCS):
Locate wire 32, Purple, and move to pin #31
In the case
will need to disconnect the boost control module under the hood - not
the solenoid - but the box it plugs into it a little lower on the
passenger side fender. The PE's and LA3 ECU's have this control system
built right in.
Locate wire 35,
yellow wire, and move to pin #33
This is optional. Many
people running the 85.5 and 86 upper and lower intakes do not bother to
tap a hole for this sensor. There is no proven benefit to drivability,
MPG or health of the engine. My 84 runs perfect and puts out at least
220RWHP without it. If you are swapping for a TC lower intake, then the
ACT bung is there and has to be filled anyway so it's up to you if you
want to run the wires. I plan to do this swap myself and will post a
blurb on it when I get to it.
If you are
ACT, pin a wire to 25 long enough to run it behind the carpet or
against the fire wall to the driver side and through the main wiring
harness grommet and then tack on two feet. That should give you enough
to rout it neatly to the sensor location in the lower intake.
wire with a
white stripe going to the throttle position sensor, water temp sensor
or fuel injector harness and tap into that for the signal return.
all the wires, slide the red locking tab back into place. Make sure the
wires you just moved don't get pushed out again during this step. Just
pull slightly on them to make sure they are all secure. Replace the
black wire guard and tighten the plug hold down bolt.
putting the ECU back into the inner fender, start the car and make sure
things are working. I recommend you make sure the ECU is sitting
securely. Move everything from the floor and take the car out for a
spin. Drive normal, test a bit of boost, but not too much, then if
things are working good put it all back together and take it out for a
good run. It may be wise to pick up a cheap A/F gauge. Just install it
quick and dirty and look for the smooth max rich - max lean light
pattern the signals things are working properly. A wide band test via
Dyno is recommended.
Don't be too
don't notice a difference in idle or performance the second you start
and test the car. It will take a bit for the ECU to re-learn from its
last application. My first install failed outright due to the use of a
bad auto ECU. The LB series computers may be ok to use, but until I
have a few to test I won't claim anything one way or the other. Once I
put in the LA3, my car ran a little
rough for about 1 minute. After that the idle smoothed out and that
common SVO miss
was gone. Upon the drive test, I sensed a power gain right across the
RPM range and no more sulfur smell in the cat. The car started, idled
and ran perfectly from that day on.