If you want a
printable checklist while you are doing the swap, left-click or
right-click/save-as here: Turbo Swap Instructions
1. Intro
This
is specific to the '87-90 LX cars receiving the '87-88 Turbo Coupe computer and VAM
harness.
These notes are for a 5speed car only, but should be close if you wanted
to do an auto trans conversion. (who would do that)?
First off try to use as many pieces as possible from an 87-88 Turbo Coupe,
as it will simplify the conversion process. You do not need the whole
wiring harness from the t-bird, only the VAM harness connector. DO NOT
remove the harness from the Mustang.
Read this article carefully and you should be set on how to wire the
conversion. If you do not understand something feel free to study that
area until you do understand. If you do not you could end up messing up
something that could be costly to repair.
Also feel free to email me with any questions, or if you find any errors
in this article. I will not accept responsibility for anything you might
fry in the process of doing this swap. I advise researching all the wiring
diagrams and EEC IV info you can get your hands on.
I am not going to explain how to remove and install pins from a connector,
if you can't figure it out you might not want to do this swap. I will
give you a hint though, a small screwdriver or small razor knife works
well.
2. How
to Connect VAM Wiring
From the VAM wiring
harness from the Turbocoupe:
Connect the VRef (orange/white) to the wire going to pin 26 of the stock
harness (also orange/white). This
pin is the voltage reference and supplies 5v to all sensors that require
it under the hood. You can tap (piggyback) into this wire to supply the
VAM its power at any spot along this line OR you can snip the end off of
the EGR valve, lengthen it and use that as it is an extra 5v line that is
no longer needed as you will no longer use the EGR. If you DO plan to use
EGR, just tap into the wire as stated above.
Connect the VAF (white/black) to the wire going to pin 27 of the stock
harness (brown/light green). (This wire going to pin 27 can be found
at your EGR plug. This means you will no longer use your EGR. If you do
want to use EGR, you'll need to move the EGR pin to the proper location
and run a new wire from Pin 27 to the VAF (white/black) wire.
Note: Remove unused Pin Connector #3 from LX wire harness red block (or
take one from your TC harness you salvaged) and put this pin connector and
wire into the red block of your LX harness to plug into your Pin 43
position on the TC computer. The LX harness lacks this connecting pin.
Connect the Vane Air Temp (light green/purple) to Pin 43 using this
transferred wire you have moved into position 43.
Note II: Splice into/"T" connect the VAM signal return (black/white) wire
into the LX harness (black/white) wire that goes to pin 46. Do not cut
the LX harness (black/white) wire going into pin 46, simply connect this
VAM signal return black/white wire to it.
3. ACT
Wire Conversion
No changes necessary.
Connect ACT wire to the wire going to pin 25 (green/red). This is a plug
in on the ’87-90 LX cars using the ’87-88 TC computer since we have an ACT
sensor.
4.
Premium Mode Wiring
Cut the wire going into pin 24 of the LX harness about 5” above the
wiring block. This is an Air Conditioning Wire. The Air Conditioning will
still work properly with this wire cut and capped – this was an idle
increase control wire for the Air Conditioning. The 5” section of wire remaining,
going into the computer is your pin 24 octane control. Take this wire and “T”
this into pin 46 signal return. This will complete the connection and
allow your computer to run in the “High Octane” setting. You must from
this point on, run 91 or greater octane fuel. If you want to be able to
switch between regular and premium fuel like the factory setup, simply
wire this to a switch that will ground for Premium fuel.
5.
Closing
Unplug the vacuum
hose going to your MAP sensor and leave it unplugged on the MAP, Then cap
the vacuum tree port where the vacuum line plugged into the tree.
The above information does not include wiring in the Electronic (computer)
Boost Control, so you will need to add a preferred (for greater boost)
Adjustable Boost Valve, ignoring computer control of boost. I prefer the
Gillis Valve found at www.boostvalve.com.
You
should use the Mustang injector harness. The TC harness has some
more wires integrated into it and complicates the swap. Make sure
you use the TC injectors though. They are not interchangeable.
6. Helpful Info:
Step-by-Step Swap Turbo Swap Instructions can be
found
HERE
