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[Omegafantasy]

Hi all,

I'm thinking about converting my Y26SE which currently have X25XE electronics to the standard Y26SE coil-per-plug system. I want to do this since I haven't changed rocker covers and my DIS-pack is acting up. Does anyone have a pinout for the connectors on the newer coils? Shouldn't be much of a problem connecting it to the ECU I already have, but without schematics for the coils it's a hard guess.

Thanks in advance 

[Omegafantasy]

I went to my workshop and fetched my coilpacks for the DBW-engine and did some measurements.

This is my results so far:

Code: [Select]

Coils 1-3-5 (black connector) Bosch# 0221503026
1 HT GND ? (4.88 MOhm relative to each spark plug, negative at pin 1)
2 Common LT (probably positive supply)
3 Plug X (0.3 Ohm)
4 Plug Y (0.3 Ohm)
5 Plug Z (0.3 Ohm)
6 N/A

Coil 2-4-6 (gray connector) Bosch# 0221503027
1 HT GND ? (5.23 MOhm relative to each spark plug, negative at pin 1)
2 Common LT (probably positive supply)
3 Plug X (0.3 Ohm)
4 Plug Y (0.3 Ohm)
5 Plug Z (0.3 Ohm)
6 N/A

Can anyone point out which coil is which? Really hard figuring out when these aren't configured as auto-transformers.

Measuring the pin 2 (common) relative to 3, 4 or 5 i get low resistances indicating primary windings (to confirm, you get double resistance between 3 and 4, 3 and 5, 4 and 5).

A common ground for the HT is probably pin 1 as I measure a very high resistance relative to the spark plug ends, although, they are acting semiconductor-ish. Several megaohms, but only in ONE direction? Got to be something in between, a MOS-FET or some random electronics.

Having these datas, I think I can hook it up somehow, but no way of telling which coil each pin in the connector is for.

Been searching around the net trying to find at least some data or schematics for this, but to no avail. Not even Autodata have any info TIS isn't working here so I'm kinda lost.

If anyone have any info or ideas, please share some with me

[Omegafantasy]

Ok, done some testing here with the coilpacks.
Hooked it up to a power supply and tried to make sparks at the workbench to find out which pin was for which coil.
This is the results:
Pin 3: X
Pin 4: Y
Pin 5: Z
Where X is closest to the connector end (cylinder 5 and 6).

I connected pin 1 to ground, pin 2 to +12V and pulsed the negative on pin 3, 4 and 5.

What I would like to know now, is what exactly is pin 1 connected to on the DBW engines? Please, can anyone check this on their car or schematics?

My power supply (digital wonder-machine) went nuts now and then, possibly due to HT feedback from the HT ground (pin 1). I don't want to fry my ECU because of that :p

[Kevin Wood]

I'm pretty sure pin 1 is connected to ground on the DBW cars.

I suspect it's  probably just the negative end of a suppression capacitor to the positive supply, or perhaps screening?

You will get a high voltage inductive kick (and probably a little spark) at the LT side as you disconnect the power supply and the coil fires and this is probably what's upsetting your power supply. The coil drivers in the ECU will be well able to handle this.

How are you thinking about driving the coils? First problem will be that the coils are going to be firing twice as often on a wasted spark ECU, so may struggle to charge fully in-between sparks to give a strong enough spark with the available dwell time.

Second problem is that you will have to drive 2 coils in parallel from each ECU coil driver. The coil driver will have a current limit which may or may not be sufficient to charge the 2 coils.

To be perfectly honest, I would stick with the original coil pack and leads. The newer setup is no more or less reliable and I can see it being compromised if driven by the wasted spark ECU.

Kevin

[Omegafantasy]

Thanks for the reply, Kevin.

Yes, I think it might be a little inductive kick back into the PSU causing that, just never seen it acting up on me (and I've fed it with some nasty RF returning from a radio).

First, I think I will try to drive the coils directly from the ECU, in parallel so I waste a spark. If this fails, or I can make a clever driver for it, I will make a circuit hooking up to a suitable signal for selecting coilpack and avoiding waste spark. Might even fit a better driver for it).

It seems like the newer packs can drive the four-electrode spark plugs better than the standard DIS-pack, and I know I have spark problems..

The main problems are:
1: I haven't changed cam covers, leaving huge holes with normal plug leads (filling with water and dirt). I could change the covers, but as I've never done it before, I'm pretty sure I'll screw something up. The ones fitted are perfectly tight (wow).
2: My DIS pack and plug leads are knackered. Replacements in Norway is a months wage. Fleabay is an option, but would take a lot of time and problems during transport (read: Norway again).
3: I want to try something new, different 

As it is now, I think my engine is running four pots with occasional fire on the last two. It drives like a 2-litre..

Oh, forgot to mention; the resistance of the primary windings of the new coil packs is somewhat higher than on the older DIS-pack, so load-wise I don't think the ECU will struggle.

I just want my engine to have some guts Hate getting left behind from red lights 

[Kevin Wood]

I would say that the 4 electrode plugs should be no more challenging than 2 electrode. Only one electrode ever sparks so the only advantage of having 4 is that it takes longer for the electrodes to erode away and the plug has a longer life.

Because the COP coils only fire every second rotation of the engine ordinarily they have twice the dwell time available to "charge" the core with a magnetic field. This might be why the primary impedance is higher, and it might mean they don't work too well on a wasted spark ECU.

Of course, the dwell time is under the control of the ECU, so even if you had a scheme to alternate the coils and avoid the "wasted" spark you would probably still be stuck with the dwell time.

I would say it's easier to get one of us to put a 2nd hand coil pack and leads in the post but there's no harm in experimenting. 

I think the dwell time is shown in live data so next time I have the Tech 2 out I might be able to compare the values.

Kevin

[Omegafantasy]

A little Tech2 data about that would be great!
I am not sure if the dwell time would be an issue, too many parameters needed to even try calculating that, but I guess a little test would be sufficient to say if it works or not.
If I make a controller/driver for it, I could change it anyway I want it. It could be a nice little project, but hardly worth it.

If it fails I will source a new DIS-pack and leads. The problem is more about the cam covers really. If I save some money on the HT side, I could spend a bit getting the cam locking kit (which I find far more important).

Thanks for the info, Kevin. I will post some results when I get around doing the modification. Getting a new (DBW) ECU and loom would probably cause way too much trouble fitting into a pre-historic miggy  :-/ Someone tried Megasquirt on the V6?

[Omegafantasy]

Hmm.. As always, the schematics and manuals doesn't describe anything in great detail. The DIS-pack connector (4 pin) is missing references to which coil each pin are for.

Pin 4 is positive supply
Pin 1, 2 and 3 is my big question. Anyone have schematics that show this info?

Plug 5&2, 6&3, 4&1 is firing at the same time, but I wonder which pin each corresponds to.
This is all the info Autodata gives me 

[Omegafantasy]

Project update:

In between all the showers of rain today, I have converted my engine to coil-per-plug. After trial and error-method finding out which pin was for which group, I got it running. Seemed fine on idle and pretty responsive when revving it, but occasional misfire would blow in my intake and even stall the engine. Grr...

Anyway, it's tried and deemed "not good enough" after this short experiment. I put everything back to original, but while doing that I saw several plug-leads that were torn into the core. No wonder I have misfires! Next up: Source a DIS-pack, new leads and probably some plugs. (Did I mention that the DIS-pack is a blasted piece to reach into?)
My DIS-pack is the very old kind with square connector on the long side and mounted with its back onto the cylinder head. Hope EPC will give me some numbers..