Location: Southern MA
Posts: 973
My VIN: 767 (3.0L EFI/EDIS)
Location: Southern MA
Posts: 973
My VIN: 767 (3.0L EFI/EDIS)
Yup, that's the piece I was missing -- I found a picture of the pulley when not on the car, and it's clearly much more than 6 teeth off of the top (assuming I'm looking at it right). This would account for the position of the VR sensor when combined with the BAC firing order.
I was just curious about how the sensor position and firing order worked with regards to the gear I have. I didn't have to think about it before, so I just bolted the parts on, but now I want to know how the alignment works. It all makes sense now. (I think. I'm not going to worry about it too much.) Of course, it's really hard to see what it looks like mounted in the car, with the belts blocking the view and the muffler limiting what I can see, so I have to resort to old pictures.
Thanks again
-- Joe
IMG_8924.jpg
Last edited by jangell; 12-04-2017 at 06:19 PM.
From the looks of that tooth wheel, looks like six teeth is a lot more than 10 degree. Or does that 6 tooth count have nothing to do with base timing? How many teeth are on the wheel?
Dave M vin 03572
http://dm-eng.weebly.com/
Location: Southern MA
Posts: 973
My VIN: 767 (3.0L EFI/EDIS)
Sorry, it’s a 36-1 missing tooth gear, so each tooth is 5 degrees, and from the leading edge of one tooth to the leading edge of the next should be 10 degrees. In a normal EDIS setup, the VR sensor has to be 6 teeth before the missing tooth (so, 60 degrees), but I think everything is offset to make it easier to mount the VR sensor.
— Joe
Location: Florida: Pinellas County
Posts: 2,106
My VIN: 5003 Never placed Concourse
Club(s): (DCF)
You should really research some articles on this for the information you're looking for if you'd like a better understanding.
Here is a moving picture of how the wheel and sensor can be: https://wiki.autosportlabs.com/Ford_...al_information
Again, you can have the wheel and sensor at ANY position, as long as the missing tooth is 6 teeth away and the crank is at TDC, as you can see in the above site.
I believe this webpage will answer many, if not all, of your questions.
http://www.megamanual.com/ms2/EDIS.htm
The EDIS will fire a coil based on the missing tooth. It sees the missing tooth pattern, knows exactly where TDC is and then fires the proper coil accordingly as the crank and wheel turns. If you have a bad sensor, your engine will crank but not start because EDIS isn't seeing where TDC is in order to fire a coil. The coil is set up ABC but the EDIS fires it ACB, meaning it fires left coil first, right coil second and the middle third - and your wires need to be arranged accordingly. If you put the spark wires on thinking it fires ABC you'll be misfiring because the two coils have the spark wires wrong. The firing order is 1 6 3 5 2 4. 1&5 are connected to A coil, 6 & 2 to the C coil and 3 & 4 to the B coil.
Since you're doing COP, I do not know how this impacts you.
Last edited by dn010; 12-05-2017 at 11:24 AM.
-----Dan B.
Location: Southern MA
Posts: 973
My VIN: 767 (3.0L EFI/EDIS)
I’ve been referencing that MS EDIS page you linked to quite a lot lately. I understand how EDIS is set up and how the missing tooth gear is read by the the VR sensor and EDIS, then sent to MS, and how MS sends back the timing offset for EDIS to actually fire the plugs. I also understand that the placement of the VR sensor relative to the missing tooth on the gear and TDC is important to get a correct reading, and how to time EDIS from a running engine by disabling the input from MS to enable the EDIS limp-home mode so that I can read exactly the timing with a timing gun, then adjust the VR sensor until it is exactly 10 degrees.
It’s more that the documentation that Josh sent me for his setup uses BAC firing order instead of ACB, but that’s just ACB rolled to the right one letter — the sequence is the same, but rotated 120 degrees. This, and possibly the location of the missing tooth relative to the top of the pulley (which that animation you linked to clearly illustrates — thanks), may explain the location of the VR sensor in his setup (the lower left side of the pulley). This is what I’m wondering about — the decisions that led to BAC, the sensor position and the toothed gear offset. I think it’s a just slightly unconventional setup, but that it does work properly. I’m doing this more from curiosity, since I know Josh’s setup worked on his car. It doesn’t have anything to do with actually testing the timing at this point.
Just to clarify, I think Josh both offset the VR sensor by some amount of teeth, AND he offset everything by another 120 degrees by using BAC instead of ACB. I admit I was a bit fuzzy on the sensor 6 teeth off from the missing tooth irrespective of where the top of the gear is until you posted that animation, so that was very helpful. I just wish I could see the pulley on my engine better with the belt in the way so I could count the teeth from TDC to the missing tooth, and from there to the VR pulley, so that I knew for sure how everything was set up and if BAC is really correct.
And I do believe you are completely correct about the timing being off by a significant amount, quite likely far more than 3 degrees given the amount of adjustment available in the VR sensor bracket, and that I need to address this before anything else. I don’t think CoP has any effect on this, other than how I hook up the timing gun, which now doesn’t seem like it’s going to be a problem.
Fixing the timing will definitely be the first thing I address when I get a chance to get back to the garage.
— Joe
Last edited by jangell; 12-05-2017 at 12:02 PM.
Location: Illinois
Posts: 2,440
My VIN: 11408
Club(s): (DMWC) (TXDMC) (DCUK) (DOI)
The coil on plug functions EXACTLY the same as the common coil pack and spark plug wires. It is still wired up as batch ignition. I kept breaking spark plug wires so I went this route.
The trigger wheel was welded onto the crank pulley 6 teeth off TDC.
Supercharged 5.3L LS4 + Porsche 6spd
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I am not affiliated with Delorean Midwest in anyway.
Location: Florida: Pinellas County
Posts: 2,106
My VIN: 5003 Never placed Concourse
Club(s): (DCF)
Please, correct me if I am wrong- but doesn't each COP need one pin to have +12VDC and the other pin to have the input from EDIS module in order to fire? According to your wiring diagram, only 4-5-6 gets the +12VDC while 1-2-3 only get the signal from the EDIS module.
-----Dan B.
Location: Southern MA
Posts: 973
My VIN: 767 (3.0L EFI/EDIS)
The two coils are hooked up in serial. The path is EDIS -> Coil 1 -> Coil 2 -> 12v. Since the coils only have two pins, you can just insert another coil in between, as long as there's enough power to actually drive the coil. It's the same idea as putting two light bulbs on the same circuit behind a switch, where the switch controls both lights together. When the EDIS pulls the pin low, it completes the circuit and lets power flow through both coils to 12v.
I guess hooking them up in parallel would have worked too (EDIS Pin 12 -> Coil 1 -> 12v, and EDIS Pin 12 -> Coil 2 -> 12v). I think that provides a more dedicated power source to the coils, since both coils aren't stressing the same wires, but I'm a bit fuzzy on that, and I'm not sure the difference in load is enough to matter in this situation. I know JUST enough electronics to make an Arudino control some things in my house and in response ti my computer, but I'm certainly no expert on any of this.
-- Joe