Edis
From E-type-Lovers
This is a discussion of the Ford EDIS (Electronic Distributorless Ignition System).
Some enthusiasts are now adapting this system to older classic cars. Both Mike Goodwin and Ray Livingston are running this system on their 6 cylinder E-Types. Nick Johanneson is running this on his S1 XJ6.
NOTE: If your mechanical skills are limited to changing spark plugs and oil, this article is probably not for you. Fabricating an EDIS system for an older car is an exercise in metal working, electrical wiring, and a bit of computer savvy. If this doesn't describe you, perhaps a Pertronix, Crane, or Mallory system that installs out of the box is for you.
If you think you have the qualifications or are just curious, read on!
(Click on any image for a larger view)
First, some principles:
The EDIS system uses a 36-1 toothed wheel with a magnetic pickup sensor to sense the position of the crankshaft. The trigger wheel will be the hardest part to find. Some late model Ford vehicles used trigger wheels that are removable and might be adaptable for your use. The wheel mounts either on the crankshaft damper or a pulley that is solidly connected to the damper.
There are various versions of the wheel but the one I had made looks like this. It is 5 - 3/4 inches in diameter and .216 (5.5 mm) thick. The wheel has to be steel for the magnetic sensor to read it.
36-1 actually means that the wheel has 36 teeth minus one. Each tooth is spaced exactly 10 degrees from it's neighbor. The missing tooth gap is used to indicate top dead center for the engine. The same wheel is used for 4, 6, or 8 cylinder applications. The sensor position varies with the number of cylinders. For a six cylinder engine, you mount the pickup sensor 60 degrees before TDC.
The pickup sensor feeds an electronic EDIS module which drives a coil pack. The coil pack is made up of multiple high voltage coils with a spark plug connection at each end of each coil.
Here's a coil pack for a six cylinder engine that uses the regular distributor wire boots. This is the coil for a 2003 Ford F150 2WD pickup. Here are some cross reference numbers for it:
Motorcraft - DG485
Ford - 1F2U-12029AC
Wells - C1312
AC Delco - C562
Standard - FD498
AutoZone carries the Wells C1312 for $72. They can also supply the Visteon brand, part no. 60-2001 for $81.
Salvage yard price is usually around $30. This uses the Motorcraft WPT508 rectangular primary wire connector.
Which ever coilpack you acquire, make sure you get the proper primary wire connector that fits it. There are several styles, an oval connector that is available aftermarket from places like NAPA and the rectangular OEM connector which is only available from Motorcraft or Ford parts stores. The oval NAPA connector is about $14, the Motorcraft rectangular connector part number WPT508 is about $25.
It is a "Wasted Spark" system in that it fires both plugs at the same time but since one cylinder is on an exhaust stroke, nothing happens in that cylinder. Only the plug in the cylinder that is on it's compression stroke will ignite the mixture.
This is an EDIS module for a six cylinder engine. Note that it says EDIS6 on it. All three models of EDIS modules look the same except for the label.
The EDIS pack, coil pack, sensor, and sometimes the 36-1 wheel can be found at many automobile salvage yards. If you go looking for one, make sure the EDIS module is the correct one for the number of cylinders in your engine. Using the wrong EDIS module will be a waste of time and since they are wired differently even though they all use the same connector, you may damage the module.
EDIS4 would be for a four cylinder engine.
EDIS6 would be for a six cylinder engine. Ford Part No. is F4ZF-12K072-BC. The mating connector with all the wires is part number F07B-14N003-A.
EDIS8 would be for an eight cylinder engine.
Here's the pickup sensor I found: Ford Part No. is F3DE-6C315-CB. There is a similar one that has the connector coming off at a different angle that is part No. F3DE-6C315-AB. Either one will work.
Also grab the connectors and a few inches of wire off the wiring harness if you can. While some of the connectors are available after market at places like NAPA, a Motorcraft store, or a Ford parts department, they aren't cheap. See my notes on the coilpack connector above.
It is possible to use a non-Ford crank sensor as well. For instance, the Marelli crank sensors on the 1990 and on V12 engines or the crank sensors from the 3.6L and 4.0L AJ6 engines work with the EDIS system as well.
You will also need a microprocessor controller to drive the EDIS module. For carburetted engines, the usual choice is the MegaJolt Lite Jr.
You want the model with the MAP option to sense manifold pressure. The unit is available as a DIY kit for $89 or fully assembled and tested for $161.
If you have ever assembled a simple Heathkit in the past, you will have no problems assembling this kit.
The instructions are very clear and just basic soldering skills and a small pencil type soldering iron are required. Make sure you use Rosin Core solder and not Acid Core. Acid core will leave a residue that will damage the board when it absorbs moisture from the air.
Additional background on the design of the original Megajolt EDIS Ignition system by Bruce Bowling & Al Grippo can be found here.
Here's some pictures of how I mounted the trigger wheel on a 1975 Datsun L28 engine. A friend machined the hub and stepped washer shown in the pictures. The wheel is clamped to the hub using the stepped washer and three Allen head bolts. Once I have fabricated the sensor bracket, I can adjust the position of the wheel. Then I will tighten the three Allen bolts and drill a hole for a locating pin to prevent it from moving.
I need to pull the damper off of the e-type and see how to drill the holes to mount a wheel on it.
To be continued....
