COP 4 cylinder - 924s/944 & other content - Very Long Po

Dean924s · Post by **Dean924s** » Wed Nov 12, 2008 2:52 am

Sorted out it looks a lot better

Dean924s · Post by **Dean924s** » Wed Nov 12, 2008 2:57 am

Note the difference in the coils

The one that is labeled

1 3
4 2

Is form a 97 contour. with the 2.2. It had no resister and it did not have an EDIS unit it was the later integrated control system.

The one labeled

4 3
1 2

Is from a 94 Escort Note the attached Resistor

Dean924s · Post by **Dean924s** » Wed Nov 12, 2008 2:59 am

Different EDIS units all from 94 escorts

Dean924s · Post by **Dean924s** » Wed Nov 12, 2008 3:07 am

The RX7 VR sensors.

My biggest worry is that I will have to modify these to get them close to the wheel. They were against wheels taht are about 1.25 inches in diamiter. I will have a 3 inch wheel. Thus the angle of the mounting brackett may ahve to be changed / bent / adjusted. FOrchinitly I have two to play with. Another hote is taht these seem to be much easier to mount due to how the brackett is configuared. Additionaly they are MUCH smaller than the Ford unit I have I will get a photo of the twe units together and post it for comparison.

Dean924s · Post by **Dean924s** » Wed Nov 12, 2008 3:13 am

This I found interesting. I noticed that all the EDIS units are mounted in the escorts so that the plug is facing down. I assume that this is to make sure that water will not collect in the plug of the ellis unit and short it out. The photos are of the bracket that mounts the EDIS unit note the downward angle that the plug is mounted in. I don't remember this being noted in any of the information I have read but it may be a good thing to considder when mounting your EDIS units.

The first photo is looking down on the EDIS unit and the brackets. The other we are from the side and the front.

Dean924s · Post by **Dean924s** » Wed Nov 12, 2008 3:15 am

Must have part for mounting the coils. Make sure you keep the screws that mount the coil to the bracket.

alexander · Post by **alexander** » Wed Nov 12, 2008 8:40 am

dean,
re the resistor... i am fairly certain that it is only for suppression of radio interference, and so has no importance for this application.

re the slightly altered marking on the sticker.. heaven only knows why the change, but it makes absolutely no difference. the '1' and '4' are just the opposite ends of a single coil, so it makes no difference at all which you consider at 1 or 4.

re the mazda sensor... just as a matter of interest, did you select that because i showed it in a couple of my threads, or did you independantly know of it? i only knew of it because someone else who had made the same conversion told me. just curious...
anyway, if you didnt have good look already, see this post:

http://www.autosportlabs.org/viewtopic. ... ight=#9080

where patriq had put the same sensor on the edge of 90mm / 3.5" wheel. so i am sure the mazda sensor will fit your 3" wheel.

regards
alexander.

Dean924s · Post by **Dean924s** » Wed Nov 12, 2008 2:03 pm

alexander,

I actually know alot about the Mazda units I have raced FC's for many years. I use to do motor swaps in my IT prepared FC in a mater of hours. (missed shifts are a bad thing). I did not however immediately think of it. It was reading threads here that jogged my memory. I was actually thinking of using the cam position sensor from the 1994-1995 3.8 V6 ford Mustang. It is similar to the Mazda unit as it is mounted where the distributors were in the older 3.8's They don not have a tooth gear in them there is a cup shaped piece of metal that spins by the sensor. I think it is more of an on off or high low wave of long duration. They are also a very small sensor I just dont know what there resolution is. There are two of them. An early and a late model. I suspect that they would work. I know where one is in the junk yard and I may go get it and try it. However I really like the Mazda units. They are so much easier to mount than the ford units. The other thing that swayed me was that it has been tested here with positive results. This was a big factor in my decision to go that rout as well as I knew where two were in the local yard. Has anyone tried the Mazda unit on a standard ford trigger wheel?

I also had another thought / Idea. The timing belt pulley on the crank of my porsche has 38 teeth and is about 3 inches in diameter. It is also about an inch wide/deep. I was thinking that I could remove grind off the end of three teeth say about a quarter of an inch and then use it as the trigger wheel. There would still be plenty of teeth to engage the timing belt. The concern / Question is can you remove that many teeth and will it still trigger / give the correct wave? Anyone tried this?

I really need to make a test bench for trigger wheels and sensors so I can test this stuff. If this was doable then mounting the EDIS on my porsche would be VERY simple! I am having several extra gears sent to me by a fried who deconstructs P cars so I can fool with this as well but for now the plan is to get it up and running with the 72-2 on the cam. I may do the duel EDIS units and use COP but that will also be after I get it running using the standard set up. Wisdom has prevailed. Baby steps are needed to get it up and running first then we can trick it out with the COP or something. As I move forward with this I will post up more of the progress.

DannyP · Post by **DannyP** » Wed Nov 12, 2008 11:56 pm

Dean, I am pretty sure the teeth really NEED to be evenly spaced, with one missing. Three teeth missing would cause too much of a gap before the next tooth event and confuse the EDIS. Of course you could try it, but 38 teeth are not 10 degrees apart, and that is what the EDIS is looking for.

alexander · Post by **alexander** » Thu Nov 13, 2008 5:46 am

hi dean, and thank you for the comprehensive update. my intuition agrees with danny, that a gap which was in fact 3 teeth wide would likely cause the EDIS to malfunction, but it is certainly worth exploring if it would be such a simple installation. i would expect that the gap needs to be 20deg wide, but it is certainly conceivable that the EDIS detects the missing tooth, then simply waits for another tooth to start counting.

for testing, i recommend buyhing a USB oscilloscope from ebay. i said this in a thread recently, but i have be spraying so much of my own ramblings here recently, that i cant remember which thread! so if i am repeating myself, i apologise. anyhow, the box plugs into a laptop and makes it into an oscilloscope. they are cheap, small, and incredible useful. you would only need to put a test wheel on a bolt, and tighten it in a drill or drill press, to test it in combination with a particular VR sensor, or tooth pattern.

regards
alexander.

Post by **brentp** » Thu Nov 13, 2008 4:35 pm

The trigger wheel must be constructed with 36 precise, evenly-spaced teeth, with one missing, giving the required 36-1 pattern.

If the teeth are slightly off you will have errors in ignition timing. If they deviate more significantly, the EDIS module will lose sync with the trigger wheel, resulting in loss of spark.

Dean924s · Post by **Dean924s** » Thu Nov 13, 2008 9:36 pm

brentp wrote:The trigger wheel must be constructed with 36 precise, evenly-spaced teeth, with one missing, giving the required 36-1 pattern.

If the teeth are slightly off you will have errors in ignition timing. If they deviate more significantly, the EDIS module will lose sync with the trigger wheel, resulting in loss of spark.

Does it measure the spacing or does it just count the teeth? If it just counts then all you would have to deal with is the offset in the tooth count versus degrees from TDC on the trigger wheel.

Also how does it determine RPM. it it is based on the tooth spacing and its relationship to the -1 then this could be an issue if is only notes the timing of the -1 in relationship to the previous -1 then it should work.

Brent can you explain how the EDIS "sees the trigger wheel?

I am going to have to try this on the bench and see what happens. If mount the gear on a drill and spin it by a fixed VR and vary the rpms I would be interested to see if the EDIS keeps up with it. I then could put a light on the plug wire and see ff it holds a constant timing mark over the RPM range. Dang it so many things to try and so little time.

Dean924s · Post by **Dean924s** » Fri Nov 14, 2008 12:49 pm

Ok I was doing some reading last night. I think I will possibly try the following.

Assuming that my trigger wheel shows up AND That the mounting of it goes to plan. It will allow for adjustment of the trigger wheel relative to the sensor. SO I was thinking that I could easily try the COP idea except that it would be a wast spark cop. Since each coil is firing every 90 deg of crank rotation this means that each plug fires 2x for every complete 720 / motor cycle. Now other than the cool factor and the down rite cheep cost of the ford COP units and you eliminate the plug wires from a technical stand point there is no reason to do this.

Brent,

How hard is it to modify the firmware in the MJ unit? I was thinking back on my original idea and I still think it may work. The thing that really scared me was not idling under 450.

I have to get to the office I will continue this taught at lunch.

dr.occa · Post by **dr.occa** » Fri Nov 14, 2008 3:22 pm

Dean924s wrote:
brentp wrote:The trigger wheel must be constructed with 36 precise, evenly-spaced teeth, with one missing, giving the required 36-1 pattern.

If the teeth are slightly off you will have errors in ignition timing. If they deviate more significantly, the EDIS module will lose sync with the trigger wheel, resulting in loss of spark.
Does it measure the spacing or does it just count the teeth? If it just counts then all you would have to deal with is the offset in the tooth count versus degrees from TDC on the trigger wheel.

Also how does it determine RPM. it it is based on the tooth spacing and its relationship to the -1 then this could be an issue if is only notes the timing of the -1 in relationship to the previous -1 then it should work.

Brent can you explain how the EDIS "sees the trigger wheel?

I am going to have to try this on the bench and see what happens. If mount the gear on a drill and spin it by a fixed VR and vary the rpms I would be interested to see if the EDIS keeps up with it. I then could put a light on the plug wire and see ff it holds a constant timing mark over the RPM range. Dang it so many things to try and so little time.

If EDIS timing were contingent on tooth counting then the missing tooth wouldn't matter if it were missing or not. the EDIS would ignore anything more than the required number of teeth "to count". also w/ the fact that the pick-up sensor requires relocating depending on the number of cylinders, it leads one to believe that EDIS timing is determined by the "Rhythm" of the passing teeth. The pulse patterns in seconds. in order for it to know When to spark at a given advance it must have a specific "rhythm count" to go off of to accomplish this. so, proper tooth spacing IS necessary. anyway, here's an old page from bowling that may answer your questions. Megajolt Light - Summary.

Post by **brentp** » Fri Nov 14, 2008 4:04 pm

To add to dr.occa's post, yes, it counts teeth, but the spacing is critical as it uses that information to determine when to fire the plugs.

If you had an imprecise trigger wheel, yet close enough to prevent the EDIS module from malfunctioning, you would have a condition where the actual ignition advance would differ from the commanded ignition advance.

Hope this helps.