Main Index of MS2-Extra Manuals

Layout of Components -- Suggested Supply points -- List of common components and part numbers

Ford EDIS Ignition System

Finding Edis in North America -- Finding Edis in Europe -- Internal Mods to the MS ECU -- Edis Wiring Diagrams -- Settings

Fitting the VR Sensor and the 36-1 wheel

Ford's Electronic Distributorless Ignition System (EDIS) is an ignition system that does NOT require a cam position signal. It can function with just a variable reluctor crank position sensor (VR sensor) and a 36-1 tooth wheel (36-1 means '36 teeth minus one', and refers to 36 evenly spaced teeth, one of which has been removed).

Because it doesn't need a camshaft position sensor, EDIS is a particularly easy way to replace distributor ignitions when retrofitting older engines with a modern computer programmable ignition. The EDIS modules are very reliable and it is highly recommended.

If you alread have an EDIS setup and want to use it then these are the mods for it:

The EDIS system is made up of:

EDIS module,
crank wheel,
crank variable reluctor sensor (VRS), and
one or more coil pack(s).

Finding Edis 4 in North America:

Early to mid 1990s Ford Escort/ Mercury Tracer with base 1.9L SOHC engine were fitted with the EDIS4 system. You can tell the engine because it has a tubular aluminium (NOT cast) inlet manifold.

The EDIS4 module is mounted just behind the fuse box on the drivers side of the engine bay, it has a label on the plug that says EDIS4. The bolts are 10mm AF. You are advised to remove the fuse box first for easier access. Cut off as much as the harness as you can.

Looking toward the passenger side end of the engine, the VR sensor is above and to the left of the end of the crankshaft. The easiest way to access the sensor is to remove the front wheel (if it's not already removed), lie on your back, and reach up from the bottom to access the sensor mounting bolts. The bolts are either small metric or star bit. Once it's off, the cable is most easily cut from the top.

The crank pulley bolt is 19mm. You will need to stop engine from turning, various methods have been suggested. 1) remove the head, put some rocks into the bore and refit the head. 2) remove a spark plug and put a long bar down the hole 3) remove a plug from cylinder with piston at BTDC and coil in some rope, remove rope when finished.

Click on images for a larger picture

Finding Edis in Europe:

1a) EDIS4 module
1989-1993 Fiesta XR2i 1.6
1990-1992 Fiesta RS turbo
1989-1994 Escort 1.6i
1990-1994 Orion 1.6i
Modules are all in the engine bay and typically located in the middle of the bulkhead or the right hand side as you face the car.
Known part numbers are: 89FB-12K072-AC, 91AB-12K072-AA

Orion CVH MPI Fiesta / crossflow Escort Mondeo with 1800/2000 engine.

Location of the VR sensor varies. On the small CVH engines it pokes through the rear flange of the engine towards the flywheel. 1.8CVH Sierra has one on the front. 2.0DOHC Sierra/ Granada is in the block at the left side way below the inlet manifold. Duratec V6 (Mondeo) is mounted near the front, it also has a cam sensor that works too.
The mounting bolts are either small metric or star bit.
Escort / Fiesta location on engine flange above starter.

Do not confuse with the ESC II hybrid module which has a vacuum tube and comes on the carb model cars.
There is also an aluminium one to avoid as well.

Click to enlarge picture of plastic hybrid module to avoid.

1b) EDIS6 module
up to 1995ish Mondeo V6 automatic
Ford/Cosworth Granada Scorpio 24v V6
Module located rear left of engine bay as you face the car.
Known part numbers are: 90GB-12K072-AB

1c) EDIS8 module
Chances of finding one of these in a scrapyard are very low! Not known to have been installed on any European built vehicles. Your best bet is either to import a module from the USA or buy new. I would suggest buying the other bits locally.
For connectors try one off another car if all the wires are in use or one off an ESC module. The number of wires used in the connector varies so check they are all there!
There is a possibility of using 2 EDIS4 modules to drive a V8. But now that the MS ECU can directly drive 4 coils (V8 in wasted spark) this is no longer necassary.

2) 36-1 trigger disc
The 1.8CVH Sierra has a useful disc pressed onto the back of the crank pulley
All of the other CVH installs have the trigger teeth cut into the flywheel and so are useless.

For a scrap yard trigger disc, remove from 1.8CVH Sierra. You will need to stop engine from turning, various methods have been suggested.
1) remove the head, put some old bolts or other junk into the bore and refit the head.
2) remove a spark plug and put a long bar down the hole
3) remove a plug from cylinder with piston at BTDC and coil in some rope, remove rope when finished
4) Jam something into the flywheel teeth

Sierra pulley/trigger assy and VR sensor

If you are after a pressed steel disc, try part no. 1078767, about £12 from Ford, this came on the 16v DOHC Granada engines, alternatively wheels are available to order from HERE

3) VR sensor
Usually it is easiest to get from the same vehicle as the EDIS module so the loom wiring colours match.
Or any vehicle with a trigger disc will yield one, so CVH Fiesta/Escort/Orion or Fiesta with Valentia (crossflow) engine with ESCII hybrid, DOHC Sierra/Granada, Mondeo.

Internal Mods to the MS ECU

Input Mods for V3.0 PCB:

Output mods for V3.0 PCB:

V2.2 PCB ONLY

Input Mods for V2.2 PCB:

Output Mods for V2.2 PCB:

Edis Wiring Diagram

Edis Wiring for a V3.0PCB:

Edis Wiring for a V2.2 PCB:

Setting the Software for Edis

In Ignition Options set the Spark Mode to EDIS and the Trigger Angle to ZERO, set the Ignition Capture to Falling Edge and Spark Output to Going High (Inverted)

Set the Dwell type to Fixed Duty in More Ignition Options.

Fitting the VR Sensor and the 36-1 wheel

Assuming you have obtained a suitable 36-1 wheel, you need to establish the correct relationship between the VR sensor and disc.
There are two methods to visualise the relationship with the same outcome.
SPECIFIC-ANGLE is defined as follows: EDIS4=90, EDIS6=60, EDIS8=50

EITHER
1) Turn your engine to SPECIFIC-ANGLE degrees before TDC (check direction of rotation!). Mount the VR sensor wherever is convenient and mount trigger disc so that the centre of the sensor aligns with the centre of the missing tooth.

OR
2) Set your engine at TDC, then put the missing tooth either 9, 6 or 5 (depending on no. cylinders) teeth in front of the sensor. (Count from missing tooth in opposite direction of rotation) This will put the centre of a tooth central to the sensor.

i.e. EDIS4 = 9 teeth, EDIS6 = 6 teeth, EDIS8 = 5 teeth (Ensure you know the direction of rotation for your engine)

Direction of rotation for this example is Anti-Clockwise for below

Direction of rotation for this example is Clockwise for below

To test this alignment it is best to run the EDIS in limp home mode. This can be achieved by disconnecting the SAW plug/socket or switching off/unplugging the ECU. Fit your strobe onto no.1 plug lead as normal (you may need to try the other tower of the pair). Ensure EDIS still has power and crank your engine, check that the timing is exactly 10deg. If not, adjust your sensor until it is. It is safe to idle the engine with the SAW lead disconnected, timing should be rock solid at 10BTDC. Don't forget to reconnect the plug when done!

The VR sensor and 36-1 crank trigger wheel must be set in the correct relationship to each other. With the engine at TDC for cylinder #1, this relationship is:

Suggested points for Supplies inside the V3.0 ECU

Component Pinouts

Pull up circuit diagram

List of component part numbers used in the ignition section:

Please note: Above part numbers will need checking, some components will come with a minimum order in multiples of 5 and 10.

If you have a question, comment, or suggestion for this FAQ please post it on the forum.

No part of this manual may be reproduced or changed without written permission from James Murray, Ken Culver and Philip Ringwood.