EEC -IV Equiped EDIS-8 Applications

Did the engines using EDIS 8 and the EEC IV need a cam position sensor? I sure would like to use the EEC 4/EDIS 8 system fitted to a 1998 4.6 DOHC engine I'm building. It would eliminate ALL sorts of "Flash" problems with the '98 ECM that came with the engine. If the EEC4/EDIS 8 set up DOES need a cam position sensor, there's one (I THINK) on the front of one of the heads on the '98 engine...but I'm HOPEING it's not needed...

Originally Posted by KULTULZ

Dave,

Can initial timing be modified by using an adjustable (position) crank sensor?

Yes, except with EEC-V, you can shift the sensor to bump the base timing from the factory specified 10°BTC specification. The system doesn't know any better and will run the programmed timing table from what it thinks is 10°. If you were to shift it 5° advanced, it will base at 15° without controller input. When the controller says it wants 30° you would actually get 35° in that case. No biggie, just make note of it for reference and shift your tables, as some programming software also assumes the 10° setting. Other softwares allow you to 'trim' the timing so asking 30° gets you 30°, but the limp mode base will still be 15°. I hope that makes some sense.

David

Originally Posted by dbu8554

kultulz as far as I know when you move the crank sensor it switches between EDIS 8 for a v8 and edis 6 for a 6 cylinder or 4 for a 4 cylinder from what I have read thats the only difference between the systems is sensor placement but with the computer controller you can adjust all aspects of timing, but without a aftermarket controller you cant adjust timing

The EDIS modules are specific to the cylinders, so EDIS4 only works with 4-cylinder engines, etc. Each type requires a specific sensor placement to function as specified - EDIS4 at 90°, EDIS6 at 60° and EDIS8 at 50° - relative to the missing tooth of the trigger wheel when the engine is at TDC of cylinder #1.

An interesting tidbit is that the F3 (1993) series EDIS4 comes stock with Multiple Spark Discharge as a standard feature. This was added by Ford to help clean-up the idle emissions. Like other MSD systems, the multi-spark function is useless above a couple thousand rpm as the sparks are too far separated to help due to crankshaft speeds. IIRC, the second spark by 2000 rpm is 60° after the first, making it effectively useless. The same limitation issue the famous MSD boxes have.

David

Originally Posted by 345 DeSoto

Did the engines using EDIS 8 and the EEC IV need a cam position sensor?

No, the cam sensor was introduced with EEC-V to allow sequential injection and modified EDIS scheme with EDIS built directly into the EEC with no stand-alone module. EEC-IV runs the EDIS module strictly from the 36-1 crankshaft trigger wheel and sensor, like the diagram posted earlier.

David

EUREKA! Then, if I've read and understand this correctly, I can strip the wiring (including the individual plug coils) off of my 98 engine and substitute an EEV4/EDIS 8 entire system in it's place. Basically, would that be correct? If so, back to my original question...WHICH years/Models came with the EEC 4/EDIS 8 set up?...

OK you guys let me tell you how it really works. It...It..?
Thanks for your answers. It brings me closer to understanding this and wanting to use it.
PSIG I feel there are times we may think alike and that is scary my friend.

Originally Posted by PSIG

I hope that makes some sense.

David

Perfectly. THANX!

Originally Posted by 345 DeSoto

EUREKA! Then, if I've read and understand this correctly, I can strip the wiring (including the individual plug coils) off of my 98 engine and substitute an EEV4/EDIS 8 entire system in it's place. Basically, would that be correct?

Basically, yes. You'll be doing quite a lot of wire hacking, or building a fresh harness, but that's par for the course. Be sure to verify the trigger wheel as 36-1 with the gap (missing tooth) 5 teeth (50°) clockwise of the sensor at TDC of cylinder #1. That's 50° past the sensor as viewed facing the engine from the front. If that's true, you're good to proceed.

If so, back to my original question...WHICH years/Models came with the EEC 4/EDIS 8 set up?...

That is a gray issue and would take enormous research to determine accurately. More than I was willing to research myself, as it's easier to just hit the wreckers and look. What you're after is V8's after TFI (Thick Film Ignition distributor) ignition and before EEC-V. That gives you an EEC-IV with EDIS8. I didn't pay much attention, but the last two IV/EDIS cars I cannibalized were a '91-ish Town Car and a '93-ish Crown Vic.

David

Originally Posted by iwantmore

OK you guys let me tell you how it really works. It...It..?

It's acutally simpler than I first thought as well. Let me take a quick stab at non-electronic basics of EDIS waste-spark.

The Trigger Wheel has 36 teeth with one removed (36-1), which is 10° per tooth. Using the V8 parts in the previous diagram - the trigger wheel spins on the crank under a sensor. When the sensor detects the missing tooth it resets the EDIS counter and EDIS starts counting teeth and how long it takes them to go by. It now knows the exact crank position (within .16 of 1 degree) and speed. At Tooth X (which happens to be TDC of the previously fired cylinder), EDIS sends a signal (PIP) to the EEC/ECU/Controller asking for timing advance on the next cylinder. It continues counting teeth, and if it never hears a reply, will fire the correct coil at 10°BTDC, which is 8 teeth later. It then repeats the cycle by sending another PIP at the next tooth for the following cylinder, and so on.

However, if it sends a PIP and the ECU is connected and working, the ECU will return a signal (SAW or Spark Advance Word) asking for whatever advance it wants. EDIS calculates where the spark should then happen and fires it accordingly. At TDC of the fired cylinder it PIPs again for the next cylinder, and the process is repeating. There ya go.

Since the coils are 'double-ended', they fire two complimentary cylinders simultaneously - the two that hit TDC at the same time - one for ignition and the other wasted into exhaust gas in the complimentary cylinder. On the next crank rotation the opposite happens for the complimentary cylinder. This is why EDIS only has to track 4 cylinders on a V8 (one crank rotation). If we use 5.0HO/351 firing order as example (13726548), cylinders 1/6, 3/5, 7/4 and 2/8 would be complimentary sister cylinders and connected to the two ends of the same coil accordingly. EDIS doesn't care what crank rotation it's on; it just fires the coils in order and the right cylinders get lit.

PSIG I feel there are times we may think alike and that is scary my friend.

Okay, my paranoia is spiking... Seriously, if we ever bump into each other, the round is on me.

David

PSIG;

Help me here as I am just beginning to understand what you have been doing as a friend is putting a 94 MARK VIII 4.6L 4V into a '57 FORD and I just discovered it is EEC-IV.

Are you saying (I am a little slow at times) that one can retrofit later EDIS to an earlier 5.0L? You also mention EIC. Can you give me a brand name? Can the EEC-IV ECM be flashed to provide timing advance for this changeover and also fire 5.0L SEFI?

If what I am thinking may be possible, you have just introduced me to a great idea (it is for older cars and you guys wouldn't be interested).