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!)
RS Turbo Suppressor OFAB wiring diagram
A diagram of the MAP sensor and supressor plugs, looking on to them, at the engine loom.
RS Turbo Fiesta Suppressor Wiring Diagram
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.