Here's an 83 Starlet I was working on recently. The owner bought the car fitted with a 4A-GE 16v, T50 gearbox and an AE86 rear axle. 
The engine needed to be wired up so I got an AE86 Corolla engine loom and got to work. I pulled out the standard Starlet loom and modified that to suit including routing 12v switched ignition wires and some 12v battery feeds to a fusebox mounted at the passenger footwell. I also cut out anything unnecessary like the externally regulated alternator wiring, coil wiring etc. After that I stripped down the Corolla loom and modified it as I wrote on the 4A-GE wiring guide from January. 
Here's a few pictures of it finished.

I know it is not Japanese but the MK2 Escort is one of the most sought after classics today. 
This is a project I've been working on over the last few weeks. The car was very clean and with the same owner the last 6 years. It has seen some changes from 6 years ago with the interior changed from a tacky, track ready finish. Some mechanical an suspension upgrades along the way too like adjustable track control arms, thicker anti roll bar, an LSD fitted, new shocks, coilovers, type 9 5 speed fitted with larger transmission tunnel, exhaust changed etc. A big brake kit was also purchased. 
The main plans were to tidy up the wiring loom making it more discrete and do away with some dodgy and unreliable wiring that had previously been carried out. Some minor welding was also planned, no rust repairs needed however! Other than that the plan was to get the car 100% in regards to mechanics and drive-train including completing the big brake and pedal box conversion and to get it on the road for the summer. The owner plans to strip her down for a full respray after the summer. He is a panel beater and spray painter.
Here's the car when we started.

The engine was pulled out for head gasket and studs, head skimmed, timing belt, water pump and a few more bits to be changed. The engine is fairly standard internally. Matched the inlet ports to the manifold also. Realistically this will be swapped for a 20XE redtop or 2.0 L Zetec after the summer!

The distributor housing was cracked so a refurbished unit was sourced from Burton.

Tidying up the wiring loom, deleting anything unnecessary from naff gauges and switches, fitted an Omex rev limiter, electric fan, radio, installed water proof block connectors etc. I also routed the loom differently to keep it more discrete as well as wrapped it up with convoluted tubing, spiral wraps etc.

Got on with the welding next. Filled the holes on the bulkhead for the master cylinder and heater matrix pipes that are no longer needed, filled the original handbrake hole since this car will use a hydraulic unit. Also made a bracket to mount the handbrake. Other welding included holes in the floor pan that the previous owner used to mount the seats, fabricated exhaust hangers etc. I fitted GRP4 style seat mounts for the seat rails also.

Next I cracked on with the mechanical side again while the owner cracked on with painting the floor, running gear and other bits. I made front coil-overs with new Gaz adjustable inserts, fitted the engine and box back in, made up all new brake lines from Aeroquip braided hose and fittings etc.
I thought I had more photos of all the bits as I went along and apologies for the quality of the photos.

Engine bay not quite finished yet, will be a few more changes.

Unlike the RS2000s, this Escort was never fitted with radius arms/tramp bars from factory. A previous owner had fitted them. Although the brackets and welding was very well done the arms themselves were a mess. I made up 2 new rosejointed units.

The rear end all built up.

That's it for now. The car only needs a few small bits to finish it off. As always, these cars are on going projects so I'll keep up to date with any more updates!

Also picked up a tidy slimline fan.

Since I was having issues getting a decent brake pedal I wanted to be sure I had no leaks or air drawing into the system. I bought Aeroquip fittings and stainless braided hose. Using banjo bolts on the master cylinders and other AN style fittings to ensure I have no leaks anywhere and AN style fittings are cool as fuck! Expensive though.

Made up a few new hardlines from copper/nickle too. Easy job when you've a good quality flair tool! 

I decided to do a post on 4A-GE wiring for a KP60/KE70 or any K series engined Toyota or Diahatsu since it is such a popular swap. This post is concentrates on a 16v 'bigport' TVIS engine. However it is relatively similar for 'smallport' or 20v 4A-GEs. 

Get familiar with the ECU pinout diagrams. There's a number of unnecessary things you can eliminate from here.

This page is based on using a late spec ECU and loom. If you are using early spec items pinouts and connectors will differ slightly.

4AGE AE86 MAP ECU        Toyota part No: 89661-12051        Nippon Denso Part No: 175700-0180

Power Supply Source         Wire Color                                        Connected To
'Run' via EFI Main Relay        Yellow                                       4 x main injectors & ECU 'BF' terminal 
'Run'                                         Black/Orange        Power to main injectors via EFI Main Relay, EFI main relay                                                                                       trigger solenoid power, Ignition condenser, ignition coil +ve
                                                                                  terminal & igniter

'Run                                         'Black/Red              TVIS VSV solenoid, ECU 'B' & 'B1', Idle up computer & Circuit                                                                                   Open Relay power feed

'Start                                       'Black/White           Starter SOLENOID, cold start injector & cold start injector 
                                                                                  timer

* Run is the ignition on or 'run' position of the key. 
Start is the position of the key when cranking the engine.


                                                      10 Pin Socket (Looking at ECU socket starting top left) 
Terminal  PCB Code  Wire Color                  Connected To                                     Function
1                     E01            Brown           Engine cylinder head earth point                  ECU Earth

2                    #10            Blue               All Four Fuel InjectorsFuel                    injector trigger signal

3                    STA          Black/White    Starter Solenoid                                     Start signal to ECU, cold start                                                                       Start signal to ECU, (from ignition       injector and cold start injector 
                                                                switch 'start' position)                           timer power feed 
                                                                cold start injector power feed and 
                                                                cold start injector timer (brown plug
                                                                temp sensor at rear of head)         

4                    V max      Not Used                    Not Used                                            Not Used

5                   Not Used Not Used                    Not Used                                            Not Used

6                   E02           Brown              Engine cylinder head earth point         ECU Earth

7                  #20            Blue                  All Four Fuel Injectors                          Fuel injector trigger signal

8                 IGt              Black/Blue       Igniter Assembly                                    Ignition timing signal 

9                 E 1              Brown              Engine cylinder head earth point       ECU Earth

10               BF               Yellow              Power feed from 'Run' position to     ECU Power Feed (shared with 
                                                                ECU and main injectors                        injectors)


                                           18 Pin Socket (Looking at ECU socket starting top left) 
Terminal  PCB Code  Wire Colour                          Connected To                            Function
1                 Not Used   Not Used                                Not Used                                     Not Used


2                OX               Black                                        O2 Sensor                    ECU Lambda sensor input


3                G-                Red                                          Distributor                    'G' pick up coil signal return to 
                                                                                                                              ECU


4               G1                Black                                       Distributor                    'G' pick up coil feed from ECU 


5               IGF               Black/Yellow                          Igniter                            Ignition confirmation signal 


6               T                  Black/Green                            ?                                      ?


7              THA              Yellow/Black      Intake manifold air temperature    Intake air temperature 
                                                                  sensor                                                  measurement      


8             PIM               Green/Red          Manifold Air Pressure (MAP)            MAP signal to ECU 
                                                                  sensor 


9            THW              Green                  Water temperature sensor               Water temperature signal to ECU 


10          VSV 1            Red/White          TVIS relay                                              Activate TVIS butterflies 


11          VF                 Red/Blue                                  ?                                          ?


12          E 21              Brown                  Joins to ECU 'E2', TPS, MAP, THA      ECU, TPS, MAP THA Earth
                                                                 & Engine cylinder head earth point 


13         Ne                  White                  Distributor                                            Engine speed signal


14         Not Used      Not Used            Not Used                                               Not used 


15         IDL                 Blue                     Throttle position sensor                    Closed throttle signal


16         Vcc                 Blue/Red             Throttle position & MAP sensor       Constant 5 V DC supply


17         VTA                Red                      Throttle position sensor                     Throttle angle signal


18         E2                  Brown                  Joins to ECU 'E21', TPS, MAP, THA     ECU, TPS, MAP, THA Earth
                                                                 & Engine cylinder head earth point

                                      14 Pin Socket (Looking at ECU socket starting top left)
Terminal  PCB Code  Wire Colour                           Connected To                              Function
1                 Visc             Not Used                                 Not Used                                        Not Used

2                 Not Used   Not Used                                 Not Used                                        Not Used

3                 Not Used   Not Used                                 Not Used                                        Not used

4                 Fc                Green/Red          Fuel pump circuit open relay     Keeps fuel pump on when engine is
                                                                                                                             running - acts as a latch to relay
5                 CCO            Blue/White                                ?                                                     ?

6                Batt             Red/White           Stop fuse (permanent power)    Computer memory

7               +B1              Black/Red            EFI main relay output                  'Run' power to ECU

8               Not Used    Not Used                                   Not Used                                       Not Used

9               FS                Black/Blue           EFI Main Relay solenoid trigger    EFI Main Relay fail safe trigger

10            SPD             Black/White         Chassis earth via magnetically     Speed limiter input signal
                                                                   triggered speed sensor feed 
                                                                   switch

11            A/C              Black/White         A/C Amplifier                                    ECU A/C on detection

12           EGW             Red                                               ?                                                     ?

13           W                  Green/Red          Check engine light earth                 Trigger for EFI warning/                  
                                                                                                                               diagnostics

14           +B                 Black/Red            EFI main relay output                     'Run' power to ECU

*  All PCB Codes marked in bold are redundant.

You can keep the majority of the original KP60/KE70 wiring loom. This loom will have your lights, starter signal wire, alternator, water temperature and oil pressure sensors, fan wiring and temperature switch wiring, wipers, washer etc. It also has switched 12v ignition feed for the coil that can be used for triggers to relays etc. The coil negative wiring can also be retained for a tachometer signal if you had a dash cluster with rev counter.

These two plugs are on the AE86 engine bay loom. The connect to the interior dash loom.

In this picture is theAE86 wiper motor wiring, and a few other wires in the yellow plug and ignition supply etc in the white plug.

Yellow plug

Brown Manifold earth

Black/White Starter STA Not used (use the starter signal wire from the original car loom)

Blue/Orange Wiper motor Not used

Blue/Black Fuel pump (Fp Diagnosis) Not used

Black/Red +B  connect to '87' pin on the EFI main relay *** The ecu needs an ignition power supply since it's only a small draw you could use the power supply to the carb cut off to power it. connect the carb wire to the black/red wire in the black 2 pin connector and then in the yellow plug that will be beside the ecu take the black/red wire out of it and connect it to +B and +B1 in the 14 pin ecu plug. (the carb cut off wire is the small wire on the passenger side valance, a single connector)

Blue/Yellow Washer pump Not used

Blue/White Wiper motor Not used

Black Visc ECU 18 pin connector Not used

Light Green CCO Not used

Blue/Black Wiper motor Not used

Blue Washer pump/Wiper motor Not used

White plug

Blue/Red rings Igniter (IG-  RPM)  You can connect this to the coil negative wire in the original car loom for cars with a rev counter

Black/Orange Igniter (12V supply) '87' pin from a relay (once you supply power to the igniter that will then supply 12v to the coil)

Black/White Starter  The ecu needs a signal from the starter solenoid so you could pull the original starter signal wire out of the Charmant loom and run it under the dash and connect it to the white connector. To do it right you should use a circuit opening relay to control the fuel pump.

Yellow/Green Water temperature gauge Not used (use original car loom for this)

Yellow/Black Oil pressure gauge Not used (use original car loom for this)

Red/Black Reverse lights Not used (use original car loom for this)

Red/Blue Reverse lights Not used (use original car loom for this)

You can cut the wires off at the back of the block connectors. You can either remove the unused wires from the loom or leave them in and wrap them up. For the wires you do need you can buy block connectors. This will make removing the loom easier in future. 

In this picture Yellow wire is ignition feed to injectors and black yellow is +B that runs to the yellow plug above marked with *** Run the injectors by powering up the yellow wire in the black 2 pin connection. The ECU grounds them to create a trigger signal to fire them. So a 12v battery supply through 10A fuse to pin 30 on the relay and then relay pin 87 to the yellow wire. You must also trigger the relay with an ignition power supply.


You can use a universal fuse box and supply 12v battery and 12v ignition feeds (use a 4 pin relay for the 12v ignition feeds) and then connect the wires to that accordingly. You then have safe fused power. 

For a circuit opening relay you can either take one from any 80s-90s fuel injected Toyota. Cut it out of the car with some wires attached to splice into. Here's the pinout.

B = 12v battery supply
Fc = Fc pin on ECU
STA = Starter signal wire (using the one on the original car loom)
E1 = Earth
Fp = wire to fuel pump

Alternatively here's how to make one up from two 4 pin relays.

Ignore the AFM. This generation of 4A-GE does not use an Air Flow Meter but a MAP sensor instead.

Since the KE70/KP60 used an external voltage regulator and the AE86 uses an internal voltage regulator for the alternator the wiring must be modified. It is quite simple. 

Here's what is needed for the 4A-GE alternator.

B = heavy wire direct to the battery. 
S = sense light to detect what voltage the battery is receiving from the alternator so it can regulate it.
L = warning light on the dash cluster
Ig = 12v ignition source to the alternator

You will find the sense wire going into a 2 pin connector coming from the battery positive terminal. Usually white on a KP60.

The dash warning light wire shares a 2 pin connector with a small yellow wire with black trace. The yellow/black trace is the 12v ignition supply. The dash wire is a heavy yellow wire also in this connector.  It can be found under the battery positive terminal. Solder these accordingly onto the 3 pin plug on the 4A-GE alternator. 

The diagnostics plug is a black block connector with a cap over the top. It is needed to set the base timing as well as read ECU faults. 
For timing cross the T and E1 pins in the diagnostics plug. 

Finally, this is a guide I have written. I have probably forgotten bits as I am doing this mostly from memory. I will add in parts I think of anything. Feel free to comment or contact me to add more or ask any questions. I will do a write up shortly on running a 4A-GE on carbs.

Finally fitted up all the new front and rear suspension components. Everything fits well, no issues anywhere. Must get a drive now and see how it performs.
Next on the list is to reevaluate mounting the rear sway bar and make rosejointed, adjustable rear 4 link arms.
Excuse the terrible picture quality, the dirty underside of the car and the cheap axle stands!

Sway bar fits perfectly.

Had to redeisgn the front tension rod idea for the Starlet. Rose joints on both ends of the roads wouldn't work. It allowed the lower control arms to swivel up and down. Not something you want to drive with. 
It is a simple enough change just having the tension rod to mount solidly onto the lower control arm. 
I used CDS tubing to make these joints for ultimate strength.

The old design.

Redesigned joint for the lower control arm end of the tension rod.

Here's another 4A-GE KP I was working on recently. 16v T-VIS wired in. Might do a write up shortly on wiring one up. The loom needs tidying yet but the car is running now. 

Here's a circuit opening relay I made up using 2 relays. Would have been easier to just take one from any scrap 90's Toyota. Below that is the late spec AE86 loom used. 

Here is a video of it now running. The loom will be tidied up yet.