Megasquirt-3 MS3 Ignition - Ford EDIS

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Ford EDIS Ignition System

Finding Edis in North America -- Finding Edis in Europe -- Edis Wiring Diagrams -- Settings -- Fitting the VR Sensor and the 36-1 wheel -- Checking timing -- Cam sensor

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 (VR) sensor and a 36-1 tooth crank wheel (36-1 means '36 teeth minus one', and refers to 36 evenly spaced teeth, one of which has been removed), it will not work with other pattern wheels or hall sensors.

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 the system works well. The EDIS module itself handles all the decoding of the toothed wheel and sends one pulse per cylinder to the MS3. The Megasquirt-3 code optionally supports the use of a cam sensor in addition to the EDIS system and then supports sequential fuel.

If your engine already has a different trigger wheel setup, consider utilising that before retro-fitting EDIS - many OEM tooth patterns are already supported in Megasquirt-3.

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.

EDIS-4
EDIS-6
EDIS-8
AC Delco 19017159, F1945 19017168 19017160, F1946
Autotune PT6909 PT6910, PT6912, PT7088, PT7095 PT7089, PT7092, PT7093
BWD CBE114 CBE115, CBE116, CBE52, CBE59 CBE53, CBE56, CBE57
GP Sorenson EL162 EL375, EL378 EL174
Motorcraft DY630, F0CF12A359AB, F0CF12A359AC, F1CZ12A297A, F1CZ12A297B, F1CZ12K072A, F1CZ12K072B 90GB12K072AB, DY629, DY657, DY680, DY682, DY689, DY724, DY727, F07F12K072BA, F0TZ12K072B, F0TZ12K072BA, F1TZ12K072B, F1TZ12K072BA, F4SZ12K072B, F4ZF12K072AC,F4ZF12K072BB, F4ZF12K072BC, F4ZZ12K072A, F4ZZ12K072B DY644, DY687, DY726, DY755A, DY887, F1AF12K072AC, F1AF12K072AD, F1AZ12K072A, F3LF12K072AA, F3LY12K072A, F4SZ12K072A, F5SF12K072AA, F5SZ12126AA, F5SZ12K072AA
NAPA-Echlin TP500, TP515 TP504, TP507, TP513 TP508
Niehoff FF424A FF420, FF424C, FF424F, FF425E FF421, FF425A, FF426A
Standard LX239 LX254, LX256 LX243
Wells F140, F157 F142, F158, F159, F169 F143, F144

Megasquirt connector Wiring

With MS3 and MS3X the following external wiring should be used. Note that the cam sensor is only needed for sequential fuel.

Without the MS3X it necessary to customise the Megasquirt internally. See V3.0 diagram or V3.57 diagram

Tach input setting

The Megasquirt board needs to be set for VR input. V3.0 VR setting - V3.57 VR setting
Note that this is different from earlier Megasquirt versions.

Edis Wiring Diagram

Setting the Software for Edis

In Ignition Options set:
Spark Mode to EDIS
If your module supports it (some 4 cyl) you can choose "EDIS Multispk" for built-in multi-spark at idle speeds.
Trigger Angle to ZERO
Ignition Capture to Rising Edge
Spark Hardware and Spark output to match your actual wiring.
WiringSpark HardwareSpark output
MS3X Spk AMS3XGoing High (Inverted)
D14 outputLEDsGoing low (Normal)
JS10 outputJS10Going High (Inverted)

Set the Dwell type to Fixed Duty

Notes for upgraders
MS2/Extra was wired using the opto-isolator circuit, no need to change that, but use "Falling" as the input capture.
MS2/BG was wired using the opto-isolator circuit with opposite polarity, no need to change that, keep "Rising" as the input capture.
MS2/Extra and MS2/BG often use "JS10" for the SAW output, you can leave your wiring as-is but ensure you have "JS10" set as the spark output.

Fitting the VR Sensor and the 36-1 wheel

On engines originally equipped with EDIS this will already be set. Later Ford engines also maintain the same phasing even though the EDIS function is now built into the ECU.

The relationship of the VR sensor and the missing tooth is critical, however the actual placement of the VR sensor on your engine is not. i.e. the VR sensor could be at 12 o'clock, 3 o'clock, 6 o'clock, 9 o'clock - it really does not matter! See the diagrams below EDIS4, EDIS6, EDIS8. The main diagrams show clockwise engine rotation as that is the most common, there is an anti-clockwise example afterwards.

EDIS4

Clockwise rotation (normal) - method a

Set your engine at TDC, then put the missing tooth 9 teeth earlier (more clockwise) than the sensor. This will put the centre of a tooth central to the sensor.

EDIS4

Clockwise rotation (normal) - method b

A different way of looking at the SAME phasing.
Turn your engine to 90 BTDC. 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.

EDIS6

Clockwise rotation (normal) - method a

Set your engine at TDC, then put the missing tooth 6 teeth earlier (more clockwise) than the sensor. This will put the centre of a tooth central to the sensor.

EDIS6

Clockwise rotation (normal) - method b

A different way of looking at the SAME phasing.
Turn your engine to 60 BTDC. 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.

EDIS8

Clockwise rotation (normal) - method a

Set your engine at TDC, then put the missing tooth 5 teeth earlier (more clockwise) than the sensor. This will put the centre of a tooth central to the sensor.

EDIS8

Clockwise rotation (normal) - method b

A different way of looking at the SAME phasing.
Turn your engine to 50 BTDC. 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.

Anti-clockwise rotation.
The same applies, but directions are reversed.

Checking the timing

During install it is important to confirm the timing is correct. To test this it is best to first 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!

Now that you have confirmed that the EDIS is correctly running at 10BTDC base timing, you need to check that Megasquirt is correctly commanding timing on the EDIS.
Start the engine and then on the Ignition settings menu, select Fixed Timing and enter 15 BTDC, check that you strobe 15 BTDC on the crank.

When done, reset Use table.

Cam sensor

The EDIS module itself does not need a cam sensor as it always runs in wasted spark, firing each coil pair every crank revolution. However for sequential fuel it is necessary to use a cam sensor in addition so the Megasquirt knows what phase the engine is on.

The cam input external wiring is shown above. Most original cam sensors are 2 wire VR type, so only require a ground and the signal connecting to the Megasquirt. The code works the same whether a hall or VR sensor is used. Internal configuration is required to support the cam sensor with MS3X or without MS3X.

Then the sensor must be enabled in the tuning software

The code expects the cam tooth to pass the cam sensor shortly before cyl#1 reaches TDC compression.

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.

Based on the original MegaSquirt® tuning guide: ©2008 Bowling and Grippo. Used with permission.