Electronics are about casting your net wide so you don't end up stuck on a mircro managed study of a pannel screw. Ford's DIS all about not being too smart to hang yourself.
It is the natural progression from EECIII, the brown box, locked Duraspark system, and TFI, the Gray box didital system. Thats why Durasparks had three generations, I, II, and III.
Radio Frequency interferrance screwed over many engines.
Originally Posted by Henry Ford
Look at all the dummies I got here.....
Before the Model A launch, stuck with a bunch of faulty ignition parts....
An all roads go to Rome grounding matter, I'll bet. Or inductance.
This is why others build Megasquirts and EMS 'Stinger' Controll ECU's in race cars.
EECIV is upset by low voltage matters, but because its upset by them, you
can find the problem.
I've seen Pinout 30 pull ground in EECIV in this video....
https://www.youtube.com/watch?v=1LkxGx5WJzA
https://www.youtube.com/watch?v=YAfoe5ncm9M
[bbvideo=560,315]https://www.youtube.com/watch?v=1LkxGx5WJzA[/bbvideo]
Fords smartest guys just did a full case ground check.
Que 42 to 52 minute mark...its an eye popper!
This is Power Spectural Density, and Bob Stelmasak said it best
"We'd discussed about measuring the high and low points on the voltage changes to avoid this problem.....We can do that..."7.17 to 7.45min
I've seen a host of "other" problems with those too. EECIV is best darn system for the money for its time anywhere, but small voltage changes take it offline real easy..
Sucess! They found rouge signals at
5 to 7.45 minutes...they had a plan....
https://www.youtube.com/watch?v=7RCdRKkt4ds
[bbvideo=560,315]https://www.youtube.com/watch?v=7RCdRKkt4ds[/bbvideo]
....
Even before EEC-III was released into the wild, Ford was already developing EEC-IV to meet the new Onboard Diagnostic (OBD) rules coming down the road.
EEC-IV is the most prolific of Ford’s engine computers. In one variety or another, it was found on every Ford vehicle starting in 1984. It would not be phased out of Ford’s inventory until the late 1990s. Using an Intel 8061 processor with a memory chip that could store 1 kb of ROM and 128 kb of RAM (late 2 8 kb ROM and 128 kb RAM chips were used), the EEC-IV could control nearly every aspect of the engine. In 1986, Ford introduced sequential fuel injection which would allow precise metering of fuel to each cylinder. The EEC-IV could do that. OBD-I was required, and the EEC-IV could do that. Also, thanks to a long run and some computer savvy gearheads, the EEC-IV was cracked and many homebrew systems designed to allow people to upload their own calibration to the EEC-IV. The EEC-IV was even used on Formula 1 cars, one of the earliest digital control systems for F1.
TFI down graded the traditional DS1, 11 AND 111 reluctor to a low RF trigger, and then added a PIP and SPOUT system to condition the square wave form needed to run a pure digital system.
Although all the other on line experts rabbit on about how a Crank Position sensors is for port injection and sequential injection, that's note true. Only Ford would use a Crank postion sensor to allow a Throttle Body Injection or even just an electronic feedback 2-bbl 2150 Motor Craft or Variable Venturi 2700 or 7200 2-bbl Carb to operate.
Inductance is
everything Ford engineers dealt with during the EEC prgram, from EECI, right on up to EECV.
PSD "Power Spectural Density" is about finding the pulses that can be picked up by the kind of pickup your using.
Like this
I'm lucky because I've had the best helpers in the world.
To see this stuff
Mike1157 and
thesameguy unfolded is a thing of true beauty, people.
Electronics pass a low pass fliter so a 100% reliable square wave form can be made from any source, then that gets baged into the Spark Timing Algorihm.
All Ford senosors are analogue, witha filter pass to make a digital signal. In the Kncok sensors, all used with the old G code 351 Windsor "Pnather" LTD's and Crown Victorias, you have to find the start of the peak, and the end of the peak, and then count the pulses. So any RF is eleimanted, its easier just to use an external circuit from another sensor if you can't get pasts other interferance.
As Paul Simon said once about his music. Start small, then go BIG.
"A man walks down the street
He says why am I short of attention
Got a short little span of attention
And wo my nights are so long"
Ford went through all that with the Duraspark III from 1980 to 1985 in the Lincoln and later Thunderbird/Cougar XR 7 California models. The 84-85 CA cars were still EECIII
The 100% foolproof way is to just add the 1980-1985 EEC III crank sensor, as used on the 49 States 1980-1983 Fuel injected 5.0's, the Califonia EECIII 1984-1985 Fox 5.0's
The Variable Reluctor crank sensor found on all Windsor 5.0's and all Varaible Venturi 5.8 and 6.6 liter 351m/400 engines with the Durasaprk III.
Yep, even the 335 Series Cleveland based engine in the Bull Nose Bronco 4WD's with the 5.8 351M or 400 had the crank sensor.
I've linked the pure TBi GM EST module details many times in the Mega Squirt forum here.
Full info.
http://vb.foureyedpride.com/showthread. ... istributor
trying to find the posting about a user that got his ignition system that he put together using a v6 ranger ignition block with a custom crank sensor he put for his harmonic balancer. 
Crazy that a big six tower coil pack hanging off the side is more discrete, but it sure seems like it to my eyes. 
