Efi Turbo Conversion (Rs Bible)

[Stephen Bearded Minky Hill]

S2 EFi Conversion

A picture of my S2 with the EFi conversion.

I have decided to update this page slightly, to try and help people. It would seem that it comes accross as fairly complicated, it's also been about for a good few years now, so probably it was about time it was updated! Please do take note though, it is not a step by step guide. Its a guide for people who have some technical knowledge, and are up for a bit of a challenge. This guide is for using Fiesta RS Turbo management, on your S2 Escort RS Turbo. This can be of the OFAC/OFAB type.

 

A Brief description of EEC-IV and a how it operates.

Introduced in 1990. The EEC-IV module is the heart of the electronic engine control system and is based on a microprocessor-controlled electronic circuit. It compares signals from its various electronic sensors with stored engine operating parameters, varying the engines operating settings directly according to engine load and environment.
Ignition is electronic via a DIS (Distributerless Ignition System) coil and E-DIS 4 module. From signals generated by the crankshaft position sensor (CPS), the E-DIS 4 module generates a profile ignition pulse (PIP). From this PIP, the EEC-IV module calculates a Spark Advance Word (SAW) as a means of defining ignition timing (or firing point). The E-DIS 4 module uses the SAW signal to control the DIS coil. If the EEC-IV module develops a fault, a Limited Operation Strategy (LOS) comes into effect allowing the driver to continue the journey but with restricted power and economy. Under LOS conditions SAW and PIP signals are not used.
The EEC-IV module is provided with a memory which is used for control matching, diagnosis and self testing.
With the engine running the E-DIS 4 module receives the SAW signal in a 'window' extending from 10 degrees ATDC to 170 degrees BTDC. The signal is therefore outside the ignition advance and retard range (10 degrees ATDC to 57 degrees BTDC) and cannot be influenced by HT disturbances.
When the engine is started or running at low speed, or operating in LOS mode, ignition is triggered by the E-DIS 4 module at 10 degrees BTDC and is not controlled by the SAW.
The DIS ignition coil consists of two coil windings converting the voltage signal from the E-DIS 4 module into HT and supplying this HT to the spark plugs in the correct firing order.
The crankshaft position sensor (CPS) is an inductive proximity switch reacting to the 36 webs cast onto the rear of the flywheel. One web is missing causing a gap and is used to denote 90 degrees BTDC on number one cylinder in the firing order. The signal generated by the CPS is used by the E-DIS 4 module to determine actual ignition timing. On engines with an open loop principle (as opposed to those with a closed loop incorporating a catalyst and HEGO sensor), the CO adjustment, a 5 kohm potentiometer supplies a substitute CO value to the EEC-IV module in place of the HEGO sensor. (Heated Exhaust Gas Oxygen Sensor).

 

What the above is basically saying, is that early EEC-IV ecus, certainly when the FRST was around, used an External-Distributerless Ignition System (E-DIS4) in this case. This is basically a small box, that contains direct coil driver FET's. This is controlled via your crank sensor, and via two signal wires that run to your EEC-IV ECU.

Crank Sensor & E-DIS

Your S2 ERST will not have a crank sensor. The KE-Jetronic does not need one. Very late 90' engine blocks do however have the hole to accept the CPS. There are a couple of options in order to get a decent CPS (Crank Position Sensor) signal to the E-DIS unit. The normal way, and best in my opinion, is to use a CVH EFi flywheel (this can be pinched from any FRST or XR2i, or late XR3i with EFi Pictures of the standard S2 flywheel (left) and EFI flywheel (right)) and a drilled block. The CPS used, is the same in all EFi' CVH engines, as is the small alloy carrier in the block, Picture of CPS located in Alloy carrier (I will link a template, for the position to drill this at some point soon) This can present problems though, as some people do not want to remove the engine. The other method is to use a sierra 1800cc CVH bottom pulley, and matching CPS and brackets, or use a timing wheel purchased from an aftermarket ECU manufacturer.(Trigger wheels for engine management systems). The trigger wheel would have to be fitted/welded to the bottom pulley, and brackets fabricated to locate the CPS. The center of the missing tooth should be aligned with the sensor when cylinder #1 is 90 degress BTDC.

The E-DIS system is fairly simple. A great site here on the E-DIS system, and more besides: http://www.dainst.com/info/edis/edis.html

Inlet manifold

Generally people use the EFi inlet manifold used from the FRST, or the XR2i. This is the easiest way for sure, it does however present a slight problem in the fact that the EFI cylinder heads have cutouts in the inlet ports to allow for injector flow. There are a few ways around this, one being to change the cylinder head to that of an EFi engine. This can be from a FRST or an XR2i, they are identical. Again though, some people may have a problem with this, as they have cylinder head modifications ect. Another way would be to have your cylinder head machined to have these injector 'lets' machined into your cylinder head. Or alternately an adaptor plate can be found here: http://www.ferriday.co.uk/

A list of parts required for Converting a S2 ERST to EFi, using the XR3i Loom method:

 

• OFAC Fiesta turbo ECU. (OFAB can be used but takes a little bit more work, and will be discussed a bit later)

• Ecu related MAP sensor. (OFAC ecu will need an OFAC MAP sensor)

• Fiesta turbo engine, or mixture of adapter plates and a trigger for the CPS.

• EFi inlet manifold, throttle body and charge carrier

• ACT sensor, from the fiesta turbo

• Throttle body to charge carrier pipe, still available from Ford at the moment!

• EFi flywheel, Fiesta RS, XR2i, XR3i (EFi)

• XR3i EFi whole loom

• XR3i Throttle cable and pedal

• EDIS Module and coil pack etc from XR3i (or Fiesta RS)

 

NOTE: All of the below assumes you have the XR3i loom fitted, along with all associated EFi items, such as coil pack, VSS (vehicle speed sensor) ect:

Fuel Tank/Pump & Supply

The standard S2 fuel tank and pump can be retained. If your using the XR3i loom, you will be able to just adjust the wiring at the rear accordingly. And connect the fuel lines in the engine bay, using suitable connectors for the supply, and return on the fuel rail.

Personally I used a new 1990' XR3i fuel tank and fuel lines. I took this opportunity to upgrade to an Escort Cosworth fuel pump, as it is a direct replacement with this tank. It also meant all the fuel lines at both ends marry up perfectly to the tank and the fuel filter and fuel lines.

Charge Carrier

I used the FRST charge carrier as it shares the same 70mm OD as the throttle body on the EFi inlet manifold. Using this method however, requires a late 1990 ERST rocker cover, or a FRST one. It's possible however to use the ERST charge carrier and connection pipe onto the throttle body. It may take some perseverance though to get it to push on. Silicone hoses make this ideal.

Wiring that needs to be changed on the XR3i loom

There are only a a few bits that need to be rewired. If you have used a FRST inlet the ISCV (idle speed control valve) where the ISCV is mounted on the plenum, the cable needs to be extended. Usually this is mounted on the inner offside wing on the XR3i. Solder and heat shrink this cable so that it reaches the new ISCV location. Then wrap the cables in loom tape to make it blend in, and add protection. Next is the coolant fan. The XR3i fan is on the engine bay side of the radiator, and the S2 on the outside. I used the Connector from the old S2 loom, as the connector is different on the XR3i. I just extended the wire enough to reach to the new fan location. Again, solder, heat shrink, nice black tape!

OFAC & OFAB

OFAC
The XR3i is fitted with the ECU '1AFA'. This ecu has all the correct pin locations for the ECU OFAC. With one exception, the AMAL valve. This can be added if you wish, but is generally left out. When using the OFAC ECU on the XR3i loom, you must change the ACT (air charge temperature) sensor located on the inlet runner, and the MAP (manifold absolute pressure) sensor, located on the blower box on in the engine bay. Pin 2 on the E-DIS unit is disconnected on the FRST loom. So cut this, and tape it back into the loom.

OFAB
If you have decided to go with the OFAB ECU, then you need to do a few little bits. They are not difficult, but it's important you follow the instructions correctly. You still must use the FRST ACT (air charge temperature) sensor located on the inlet runner. You must also cut pin 2 on the E-DIS unit, and tape it out of the way into the loom. You now have some pin changes on the ECU:

1) At the ECU, pin no. 27 (marked on the multiplug, brown wire) needs moving to pin 8, which is empty (this is the CO adjuster signal wire).
2) Pin no. 45 (brown/yellow) needs moving to pin 27 - this is for the MAP sensor.

Next up you have the map sensor connections for OFAB:

You should have a suppressor with your OFAB MAP sensor. It is connected in the following way: (excuse the crumby diagrams!)



If you do not have this connected, you run the risk of damaging either/or the MAP sensor or ECU. It will also feed the ECU incorrect information, causing running problems, and/or damage to the engine. It may seem however that the engine is running with no problems.

A diagram of the MAP sensor and supressor plugs, looking on to them, at the engine loom.



It's worth noting, that these supressors are no longer available from Ford, and when they were available, they were £100 odd!

However, if you need one, speak to Kenny at http://www.motorsport-developments.co.uk/ He will be able to supply you one new for £50, delivered.

Information for reference:

A wiring diagram for FRST engine management: http://www.rsbible.co.uk/escort/diagram.jpg

A pinout chart, for OFAC & OFAB:

 

OFAC

1, Red -- +ve
3, Brown/Yellow – octane / idle adjust
4, Brown/White – speed sensor
7, Brown/Green – engine temperature sender
16, Brown – current return & 40
17, Brown/Green – diagnostics connector
20, Brown – current return
21, Brown/Yellow – idle speed valve
22, Brown – fuel pump relay
23, Brown/Red – octane / idle adjust
24, Brown/Blue – octane / idle adjust
25, Brown/Yellow – air temp sensor
26, Brown/Black – throttle sensor & co adjust pot & map sensor
27, Brown – CO adjust potentiometer
28, Blue/Yellow – Pin 2 on edis (disconnected)
33, Brown/Green – Boost control valve
36, Blue/Red – Pin 3 on edis
37, Black – idle speed valve & injectors & Speed sensor & Boost control (tbc) & 57
40, Brown – current return & 16
45, Brown/Yellow – map sensor
46, Brown – map sensor & engine temp & air temp & throttle & CO adjust
47, Brown/Green – throttle sensor
48, Blue/Green – diagnostic connector
56, Blue/Yellow – Pin 1 on edis
57, Black – idle speed valve & injectors & Speed sensor & Boost control (tbc) & 37
58, Brown – Injectors
59, Brown – Injectors
60, Brown – current return

OFAB

1, Red -- +ve
3, Brown/Yellow – octane / idle adjust
4, Brown/White – speed sensor
7, Brown/Green – engine temperature sender
8, Brown – CO adjust potentiometer
16, Brown – current return & 40
17, Brown/Green – diagnostics connector
20, Brown – current return
21, Brown/Yellow – idle speed valve
22, Brown – fuel pump relay
23, Brown/Red – octane / idle adjust
24, Brown/Blue – octane / idle adjust
25, Brown/Yellow – air temp sensor
26, Brown/Black – throttle sensor & co adjust pot & map sensor
27, Brown/Yellow – map sensor/via supressor
28, Blue/Yellow – Pin 2 on edis (disconnected)
30, Brown – current return
33, Brown/Green – Boost control valve
36, Blue/Red – Pin 3 on edis
37, Black – idle speed valve & injectors & Speed sensor & Boost control (tbc) & 57
40, Brown – current return & 16
46, Brown – map sensor & engine temp & air temp & throttle & CO adjust
47, Brown/Green – throttle sensor
48, Blue/Green – diagnostic connector
56, Blue/Yellow – Pin 1 on edis
57, Black – idle speed valve & injectors & Speed sensor & Boost control (tbc) & 37
58, Brown – Injectors
59, Brown – Injectors
60, Brown – current return

 

FRST engine loom diagram:

 

Key:

1: ECU
2: MAP sensor
3: Diagnostics connector & CO Idle adjust connector
4: Current return
5: EDIS-4 connector
6: Crank Position Sensor
7: Connector to engine loom (injectors etc)
8: Speed Sensor
9: DIS Coil
10: Oil pressure switch
11: Amal Valve
12: Current return
13: Idle Speed Control Valve
14: CO Adjust POT
15: Connector to car loom

 

Looking onto the engine loom connector

Pin 1: Ignition Live
Pin 2: Pin 22 (ECU) to the Fuel Pump Relay
Pin 3: Fed From DIS coil pack to the Rev counter
Pin 4: Pin 20 (ECU) Current return
Pin 5: Pins 57 & 37 (ECU) to the Fuel injection Relay
Pin 6: Oil Pressure
Pin 7: B+ (Constant Live)

 

Heed help? An excellent forum available here: http://www.escortrsturbo.co.uk/forum/index.php?s=82dc866acb3effe600bae911781ced2a&showforum=55 I'm 'Scort' on the site. The people there are most helpfull.

 

 

EFI FAQ

Q: Do I need an EFi dash pod for my car?
A: No, you can run a wire from pin 11 on the E-DIS unit, to the back of your dash pod, to the tachometer input. This will give you a clean RPM signal.

RSBIBLE.co.uk 1.htm

[Paul]

Hi, I have copied this into our Tutorial section, great write up

[Ian71]

Great info stephen,see you at the pod m8

[Stephen Bearded Minky Hill]

No worries lads. And yeh see you at the pod, already bought me ticket

[Guest chris_g99]

Does anyone have the pictures that accompany this guide? I'm guessing they linked to the famous rsbible that has now disappeared

[zygott]

just used this guide, says no changes to wiring for ofac, mine matches that and works fine

[Bertie]

Is there any way to get pictures and wiring diagram many thanks