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[Datsun 1200 encyclopedia]


From Datsun 1200 Club

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Categories: Engine Modifications | Engine Electrical System

The Ford EDIS (Electronic Distributorless Ignition System) is a digital ignition system that can operate independent of an ECU. This makes it a great low cost system for swaps. Because it doesn't need a camshaft position sensor, EDIS is a particularly easy way to replace distributors when retrofitting older engines with a modern crank trigger ignition.



EDIS parts are abundant in American, Australian and UK wrecking yards, or are available from online shops such as Boost Engineering or eBay. The 4-cylinder version of EDIS is used on many Ford models worldwide. You can make your own crankshaft wheel, or adapt one a Ford wheel. Unlike other similar system that require a Camshaft Phase Sensor, this uses a simple crankshaft toothed wheel. This system has been successfully used on vintage Beetles, recent BMWs, Datsun Roadsters and just about everything else. Total cost is about $220 - $300 depending.

Trigger wheel and sensor (as found on most 1990s Fords) can be controlled by most modern after market ECU for example the $200 MegaSquirt I in spark-only mode. No fuel injection required.

Or the triggers & sensors + EDIS controller from certain Fords can be used along with MegaJolt Lite Jr.

16008.jpgAlbum 16008

Parts Needed

The parts from the wreckers needed are about $25-$100 (about $70 on Ebay):

  • Crank trigger wheel
  • Crank sensor
  • 4-tower coil pack
  • Spark plug wires


AND either:

  • ECU of you choice (starting new at $200 USD)


  • EDIS module with a bit of the wiring + MegaJolt/E ($145 and up)
  1. A brand new EDIS module is about $85.
  2. Quality Refurbished EDIS kits and more available from Boost Engineering


Using EDIS alone, it outputs a fixed spark timing of 10 degrees BTDC. You can drive the car like this! But it won't be very fuel efficient or particularly powerful. Using a relatively simple timing controller completes the picture -- wire it in and go. Optionally you can re-program the timing controller with a custom spark curve map using a standard PC.

For detailed technical information, see Ford EDIS technical information


Our own club member sundat1200 has used EDIS on a 1975 VW Rabbit and a 2002 BMW with "great success".

ddgonzal runs EDIS on his bone-stock Datsun 1200 sedan.

Club member datto1000wagon also was using EDIS:
16197.jpgAlbum click to view 16198.jpgAlbum click to view 16199.jpgAlbum click to view 17381.jpgAlbum click to view 17382.jpgAlbum click to view 17383.jpgAlbum click to view

Distributor Trigger Wheel

EDIS is designed to use a crank or flywheel trigger, using a 36-1 trigger wheel. However, for nostalgic or sleeper look, some might choose to fit a wheel into the old distributor. In this case, since the distributor runs at 1/2 speed of the crankshaft, use a 72-2 wheel.

In general it is not recommended to use distributor trigger:

  • More work, needing special wheel and custom mounting
  • Will still be affected by gear lash timing inconsistencies (but will work as well as a stock ignition system)

A low profile (sheet metal) trigger wheel takes almost no space on the front pulley, so there is almost no technical reason to use a distributor trigger wheel.

Crank Trigger Wheel

The trigger wheel on the crankshaft has 36 teeth, with one missing -- the 36-1 style. Any wheel of this style can be used.

  • You can make your own crankshaft wheel out of sheet metal
  • or adapt one from the Escort, F-150, Falcon, Mustang, Taurus, or other Ford models starting from around 1991
  • Ford UK trigger wheel Part No 1078767 is only 13 UK Pounds, and can be glued or bolted to most crank pulleys

Ford F7CZ6316BA is a nice looking cast aluminum trigger wheel and an appropriate size for Datsun A-engine. For more info see below (section Dimensions)

Bolt-on Method

16001.jpgAlbum 16001
See detail below in section A-series Kit

DIY Auto Tune wheel - low profile (1/8") sheet metal type
174_622f73a8d2b65.jpgPost 496710
Super-simple to install, needs no machining as the crank bolt alone will hold it in place. The photo shows a set-screw/bolt, but it is not needed.

Machined Method

Method 1: A new hub is created out of mild steel and is placed in front of the stock pulley
17383.jpgAlbum click to view 17381.jpgAlbum click to view 17382.jpgAlbum click to view

Method 2: This one was made from a stock A series double-pulley machined down and a Ford trigger wheel ring fitted in place of the front belt groove
25476.jpgAlbum click to view

Method 3: Teeth cut into Stock pulley
17969.jpgAlbum 17969 17968.jpgAlbum 17968


As the Datsun A-series crank pulley is 5.5 inches (139 mm) outside diameter, you need a trigger wheel at least this large.

Ford F7CZ6316BA is a nice looking cast aluminum trigger wheel. Actually it is the entire harmonic balancer (serpentine belt pulley with trigger wheel pressed on), but the ring can be removed by heating it.

Ford part number F7CZ6316BA
1990-2001 Ford Escort/Mercury Tracer with 1.9 SOHC engine
* ATP part number 102026
* DORMAN 594033
$30 USD
* 144.30 mm OD
* 102.80 mm ID
* 9 mm thick at teeth, 7mm thick where it meets the flange
* Cast iron hub: ~28mm crankshaft diameter
174_568c53b47dda6.jpgUpload click to view
UK Ford: 1078767. Ford Germany: 98XM 6K339 AA
* 160mm OD 

Other Ford parts are too small for the A-series I think.

UK Ford
* 120mm OD
Early Mustang (pre-2000) pressed steel
2008 Ford F-150 5.4 liter 
2012 Ford E-150 5.4 liter
Ford XW1Z-12A227-AC (slightly less than 5 inches in diameter)
* DORMAN 917060

XW1Z-12A227-AC.jpg XW1Z-12A227-AC_.jpg

Late Mustang wheels are one piece with the crank hub.
* cast wheel PN F2LZ-12A227-BB
Taurus 3.8 Turbo wheels are smaller diameter than the A-series pulley:
* 120.65 mm (4.75 in) OD
* 70.36 mm (2.77 in) ID
Ford Modular V8 4.6/5.4 - PN F2LE-12A227-BC
* 126mm OD
* 32mm ID
* 1999 Ford F-150 4.6 liter part number F2LE-12A227-BC 
$17 USD
  "Camshaft Position Sensor Interrupter" $17 USD
174_568c58f73c024.jpgPost 475089

A-series Kit

With the standard Escort pulley, use hacksaw to separate the grooved-belt section from the toothed section. You will end up with a steel hub with toothed aluminum wheel.

16001.jpgAlbum 16001

  • Use a standard 5/8 inch type bushing. Pound the flange a bit to enlarge it. A longer crank bolt fits. (Alternatively you can machine a custom bushing from solid aluminum).

To fit this wheel:

  1. Using a hacksaw, cut the trigger wheel from the pulley hub. I think it is cast iron. This leaves the wheel on a flat part of the hub. If the cut is not straight, grind/file it flat so that it is correctly balanced.
    21530.jpgAlbum 21530
  2. With the 139mm A-series pulley, just take two extra pulley bolt washers to space the wheel in front of the pulley. There is no room to mount it behind the pulley.
    21531.jpgAlbum 21531
    • Stock A-series pulley bolt washer is 34.5mm OD, 0.64 in (16.2mm) ID, 8mm thick.
      • Part Number: 12308-H1000 ($1.25)
    • They can be bigger on Outside Diameter if needed.
  3. Fit a spacer inside the Escort pully hole:
    • ID: 0.61 in (15.5mm)
    • OD: 1.07 in - 1.09 in (27.1 - 27.6 mm).
      You may need to drill/file the hole out a touch to fit over the bolt
    • no more than 0.37 in. (9.3 mm) thick.
    • Drill the ID (0.54 in) out using a 19/32 in drill bit to fit tightly over the bolt. Some filing with a round file will be needed. This is just to fit the pulley laterally. The Bolt will fasten it tight. Better yet, have a machinest make a tidy aluminum spacer.
  4. Fit the longer pulley bolt and the last washer.
  5. Torque: 15-16 kg/m (108-116 ft. lb.)

The stock A-series crankshaft pulley bolt is:

  • Stock Part Number: 12309-78200 ($4.58)
    M16 x 1.50 (fine) pitch
  • 15mm diameter
  • 27mm long
  • The head is 27mm hex and about 15 mm thick.
  • Torque: 15-16 kg/m (108-116 ft. lb.)

The new pulley bolt needs to be 55 mm long.

  • M16 x 1.50 x 55 mm. ($3.15)

Will Grade 8.8 be OK? Or does it require Grade 10.8?

  • Torque: 15-16 kg/m (108-116 ft. lb.)

Fitting the Trigger Wheel

  1. Fit the trigger wheel on the crank pulley
  2. Make the sensor bracket. The more rigid, the better
  3. Turn the engine to TDC on #1.
  4. Mark the tooth that is 6 teeth anti-clockwise from the "missing" tooth.
  5. Center the marked tooth over the sensor.
  6. Bolt the crankshaft pulley bolt tight (108-116 lb. ft. torque)

15999.jpgAlbum 15999 21532.jpgAlbum 21532

  • make a plate to bolt the sensor to the front of the engine. Sensor-to-tooth clearance is 0.040 inch or less.
  • This sensor is from a Ford Aerostar van, but any sensor can be used. They come in many shapes and orientations

Audio of first run (timing retarded, but very strong and smooth spark): video (202k)

15998.jpgAlbum 15998 16000.jpgAlbum 16000 16477.jpgAlbum 16477

Coil Pack Mounting

You can mount the coil pack on the core support next to the radiator:
21527.jpgAlbum 21527

For late 1200 utes, with the battery in front, the stock coil location works well:
21528.jpgAlbum 21528

But not so well for an early 1200:
21529.jpgAlbum 21529

Distributor Plug the Hole

For a no-cost option, use a large washer and the stock distributor O-ring:
16478.jpgAlbum 16478

A flashier option is to fabricate an POSTAluminum plug. It also uses the standard distributor O-ring
26327.jpg DSCN1043.jpg DSCN1044.jpg

Aluminum plug:
19530.jpgAlbum 19530

Aluminum Plug:
16197.jpgAlbum 16197 16198.jpgAlbum 16198 16199.jpgAlbum 16199


Most installs will use the Ford spark controller (EDIS4) along with a programmable timing controller (MegaJolt Lite Jr.).

You can also use a modern ECU without the EDIS controller, in which case you aren't really running EDIS per se, but rather an ECU-based Crank Trigger ignition (which can use the Ford style 36-1 trigger wheel and/or Ford-style VR sensors). For example, you can use MegaSquirt to control EDIS. Cost: $187 USD kit, about double what #MegaJolt Lite Jr. costs. If you are going to run aftermaket EFI, MegaSquirt is is the way to go. Otherwise, use MegaJolt Lite Jr.

Ford EDIS4

Many installs use the Ford spark controller (EDIS4) + a simple timing controller such as #MegaJolt_Lite_Jr.. The EDIS4 controller can be obtained from a wrecking yard, purchased from eBay ($25) or new from auto parts suppliers like ($100 + $12 connector).

27173.jpgAlbum 27173


Speeduino can use any EDIS-style 36-1 #Crank Trigger Wheel in "ignition only" mode. Speeduino fully assembled starts at $160 USD (2022) or $10 for the bare PCB board and $23 for the CPU (Arduino Mega 2560).

Configure Tuner Studio for a "Missing Tooth" Decoder.

Use a common Ford #VR Sensor with a $25 add-on Speeduino VR Conditioner board. Or, use a more expensive 3-wire Hall Sensor without needing an add-on board.

MegaSquirt 1 v3

Megasquirt works with EDIS system using the Ford EDIS controller.

You can also use it without the Ford controller but requires modification of the wiring or purchase of an external spark Ignitor such as Megasquirt's QuadSpark ignition module to drive the coil packs.

MegaSquirt 2

Megasquirt II works directly with EDIS system -- no Ford EDIS controller required. See EDIS Ignition Control with MegaSquirt-II.

MegaJolt Lite Jr.

MegaJolt Lite Jr. can be purchased from several vendors in USA and UK, including AutoSport Labs. The ready-to-run unit is $168 as of 2015 (Megajolt/E with MAP). The complete kit is $89 USD [EDITOR: Kit No Longer Available] complete with MAP sensor. It has everything needed except the EDIS parts themselves, and external wiring.

16106.jpgAlbum 16106

The kit is fairly simple and might take about 1 hour to complete, if you are good at this sort of thing. It took me three hours to solder up, but then again, I haven't soldered up a kit since 1982. After I was done, it worked with no problems.

Get the MAP sensor version. It is better. However, if you have a lumpy idle from big cams, then you won't have a good vacuum signal. In that case, use the TPS version (which requires a carb throttle sensor).

After completing the kit, wire it into the car and drive off.


MegaJolt Lite Jr. requires mounting in the passenger compartment because it's not weatherproof. That's OK since that's where you can easily use a laptop should you wish to tune it live.

For wiring instructions and pictures for the EDIS modules -- which should apply to both MegaJolt Lite Jr. and MegaSquirt controllers -- see EDIS And Coil Pack Installation

Four wires:

  1. Ground (earth) 16 gauge
  2. IGN (hot) 18 gauge
  3. PIP rpm sensor (double-wire shielded cable)
  4. SAW feedback wire (double-wire shielded cable)


For power and ground, I used some wiring cut from an old car.

The MJLJ control wires requires Shielded Twisted Pair (STP) wire. I used an ancient electric guitar cable with small wires (22 gauge, I think). It seems to work OK, although the VR sensor itself uses 18 gauge wires.

I used 10 ft of sensor wiring, so that I can move the sensor from one side of the dash to the other, and to route it along the edge of the engine compartment. Four feet would be the minimum needed.

4-Cylinder EDIS module pinout

Signal EDIS Module Terminal
PIP (EDIS output signal) 1
IDM (diagnostic signal to ECU) 2
SAW (ECU spark control signal) 3
IGN GND (signal return) 4
VRS - (crank sensor negative) 5
VRS +(crank sensor positive) 6
VRS shield (crank sensor shield) 7
VPWR (ignition switched 12 volts) 8
COIL 1 (coil drive) 10
CTO (clean tach out) 11
COIL 2 (coil drive) 12

Optional: MegaJolt Lite Jr. has extra outputs:

  • Tachometer
  • Four outputs designed to drive LED lights, such as a shift light. You can also use them to drive a beeper, or other things.

PC Interface

You don't need a computer or laptop to test or tune MegaJolt Lite Jr. However you can test it on your desk using a serial cable:

Apparently you can tune it while the engine is running, but there is no need to do so.

Again, no laptop is needed. MJLJ comes with a built in map suitable for "all" engines (including Natually Aspirated, Turbo and Supercharged).

Timing Maps

I downloaded the "Naturally Aspirated" map to it (it comes with a dual-purpose NA/boosted map), then bolted it in the car and it worked right off the bat.

More maps can be downloaded:

  1. go to
  2. click "Ignition Map Library"
  3. click your choice
    • the "Default Ignition Map" works fine on A-series engines
    • the "Datsun 1200" map (on page 3 or thereabouts) is a stock-spec map (not a high-performance map)


Spark Plugs

I used stock A12 plugs (points type) with my EDIS installation -- it ran great. However you can use extra large gap for better fuel economy with lean fuel mixtures.

The spark plugs in the EDIS4 cars use a 0.054 inch gap. Spark plugs for A-series engine require:

  • 13/16" Hex
  • Thread: 14 mm
  • Reach: 19 mm
  • Seat: Gasket
  • Tip: Power
  • Supressor/Non Resistor: Suppressor
  • Heat Range Chart: F12 nominal (factory heat range varies)

Hundreds of vehicles use this type of plug (in same heat range). See Spark plugs for more information.

Gap 1.0-1.1 mm (0.039-0.043 in) for Datsun A-series Engine

  • Same as 1979-1982 Datsun B310 USA models
  • NGK BPR5ES-11(7634) standard type
  • NGK BPR5EIX-11(2115) Iridium IX
  • NGK BPR5EGP(7802) G-Power (platinum)
  • NGK BPR5EY-11(6937) V-Power (grooved electrode)
  • Champion 322 (RN11YC4, standard)
  • Champion 3322 (platinum)
  • Champion 7332 (RN10PYP4, double platinum)
  • Champion 9804 (iridium, with platinum tipped V-Trimmed Ground Electrode)
  • ACDelco R43XLS (standard)
  • ACDelco 41802/41-802 (Professional Platinum dual platinum)
  • Bosch 7907 (WR8DCX Super Plus)
  • Bosch 4219 (platinum)
  • Bosch 4019 (WR8DPX Platinum Plus)
  • Nissan 22401-27T65(PGR5A-11)
  • Nissan 22401-N8715(BP5ES-11)
  • Can re-gap to 1.3 mm (0.054 in)

Gap 1.2mm (0.050 inch), can be gapped to 1.3 (0.054)

  • Autolite 64 copper
  • Autolite XP64 (Iridium, with platinum ground electrode)
  • Autolite APP64 (Double Platinum, including platinum bottom on the ground electrode, 100K mile plug)
    • "preferred technology for DIS engines"
  • Autolite AP64 (Platinum)
    • 1961-1965 Chevrolet 409 V8
    • 1969-1970 Chevrolet 396 V8
    • 1985-1988 Chevrolet Nova 1.6
    • 1985-1986 Chevrolet Spectrum 1.5
    • 1985-1988 Chevrolet Sprint 1.0
    • 1990-1993 Chevrolet/Geo Tracker 1.6
    • 1986-1989 Honda Accord 2.0
    • 1985-1990 Honda Prelude 2.0
    • 1988-1997 Isuzu 2.3/2.6
    • 2001-2004 Kia Optima 2.4
    • Etc, toyota, mazda, volvo ...

Gap 1.2-1.3 mm (0.054 in) for Datsun A-series Engine

  • Nissan 22401-HC000 (BPR5ES-13) [original fitment: non-USA, non-A-series]
  • NGK BPR5ES-13(3154)
  • Denso W16EXR-U13 (standard)
  • Denso IW16 (5305, Iridium Power) 30K mile plugs, non-iridium U-groove ground electrode
  • Denso VW16 (Iridium Tough) 120K mile plugs, platinum button ground electrode
  • Mazda FEDK-18-110
    • Mazda 323 with
      • 1985-1986 B3 EGI engine 1.3L 1324cc L4 FI
      • 1987 E5 EGI engine
  • If you can find them (Japan, Europe sales)

Coil Pack

These Ford coil packs work with EDIS controller:

  • Any Ford 36-1 trigger wheel and VR sensor, e.g. Falcon
  • 1997 V8-fitted LTD with EDIS
  • Zetec engine VR sensor (which is aimed at the flywheel instead of the crank pulley)

These reportedly also with with an EDIS controller. Any coil pack without internal drivers:

  • Toyota
  • Mitsubishi
  • GM DIS coil pack (typical Holden 2-spark coils, a la GM 3800)
  • Chrysler coil pack
  • Bosch coil pack

Measure the resistance and check to make sure it compatible.

The EDIS coil pack is negative switched, with the center wire being a common 12V. It is a three wire coil. When using GM DIS 2-wire coils, tie the 12V lines together.

GM 3800 coil packs 1986-2009

23349.jpgAlbum 23349

  • FORD EDIS-4 from 1990 Escort/Tracer 1.9L. Part Number: F1CZ-12K072-A
  • new Accel 4-Tower coil pack $56.95 at Summit Racing]
  • Most European and USA Fords from circa 1990 up use 36-1 crank trigger wheels and EDIS-type coil packs. You can also buy them aftermarket.
  • Most '90s Fords use a compatible crank sensor (VR sensor)

The "standalone" EDIS module is limited to a few models, most other Fords have the EEC engine module control both the EFI and spark. In other words, they all use EDIS.

VR Sensor

Here are a variety of VR Sensors used with EDIS, they vary by how they mount and where they point. You can also use GM or Chrysler VR sensors and probably a lot of other brands. Notice the Crown Victoria unit mounts in a hole, with a tab to bolt it down.

  • PC19 straight type, 1991-1996 Escort/Tracer with 1.9 engine
  • PC27 (F0CZ 6B288A) down style
  • PC51 (1F2Z-6C315AA) straight Windstar, F150, Freestar, Explore V6 4.3/V8
  • PC74 (1F1Z-6C315DB) straight Ranger/Taurus/Mazda/Windstar V6 3.0


S-744 edis module pigtail
S-755 coil pigtail
S-812 crank and cam sensor pigtail
S-674 tps pigtail
TH169 throttle position sensor
LX239 EDIS-4 module
FD-487 coil pack


MegaJolt Lite Jr. are available mail order, so they are very easy to get. You can buy a completed unit. Self-solder kits are no longer available.

EDIS parts from Australia-built Falcons and other Fords can be used, such as trigger wheels, sensors and coil packs. The EDIS 4 controller (if needed) can be purchased mail order. If you use MegaSquirt MS-III it is not needed. 

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