[help needed] Coil on plug question

[V8Volvo245]

I've just noticed that the coils on my engine are only two wire i.e. they don't have built in ignitors. Can I still use Rusefi or do I have to go over to Megasquirt? Because I'd rather not!

Can anyone tell me?

[AndreyB]

there is a bunch of relevant topics if you search around, with a summary at https://rusefi.com/wiki/index.php?title=Manual:Hardware_Ignition

[kb1gtt]

Frankenso uses an external igniter driver. External igniters aren't hard to do, as well coil on pug typically includes the igniter. Do you have pictures or a schematic of the internals of the coil? Also what is the ohms between these two terminals?

If you need an external igniter, we can offer some advice on how to do this.

[V8Volvo245]

It's a two wire coil, so definitely needs a separate igniter source

[kb1gtt]

What is the ohms of the coil?

[V8Volvo245]

Sorry for the delay in replying- both of my multimeters were spazzing out, and ranging all over the place. Had to go out to my van and use the one in there. Primary resistance is 0.9-1.0 ohms. Rather worryingly, I couldn't get a reading for secondary resistance!

[kb1gtt]

It would appear your jag uses igniter LJA1450AF which can probably be driven by the Frankenso board.

Can you find a schematic for this module? Do you have a schematic for your donor jag?

Does your existing jag run? Can you take some measurements from the existing module?

[V8Volvo245]

I've no documentation in the Jag at all. Since running it as a wasted spark setup isn't out of the question would it be possible to control an EDIS 8 module with rusefi, like the Metasquirt boys do?

[AndreyB]

EDIS 8 module with rusefi, like the Metasquirt boys do?

EDIS module is more than the igniter, it's a black box with reads 36/1 wheel on it's own right? We do not have the code to integrate with it unfortunately.

If you know that your coils require external igniters, please consider Toyota igniter 89621-33020 like on https://rusefi.com//wiki/index.php?title=Manual:Hardware_Ignition#External_Igniter

[kb1gtt]

With the EDIS you don't need a MS unit. The EDIS is basically your complete ignition control. The MS unit only allows you to advance the spark slightly, which you probably don't really need, but sure the MS advance could allow you to get a bit more HP out of it. I would suggest avoiding EDIS if you can, as it opens the doors for things like multi-spark at low RPM for easier cold starting, and better control over things like dwell times. Keep in mind 99% of the world doesn't use EDIS, and that's probably with good reasons. One issue with EDIS is that people hook it up and it's safe timing lets the engine run. They could have a really poor MS install and they won't know it, as the MS is not required. The result is that the spark advance can be wrong which can cause sever engine damage. The rest of the world allows spark to work with the proper timing, or not at all. Wrong timing is going to do little more than damage your engine.

I don't follow your comment about the jag being coil on plug and wasted spark. Typically wasted spark was done when you had one coil for two plugs, and was done to keep costs low, as you had half the coils. Coil on plug means you have one coil per one cyl. I believe your coil on plug jag has individual cyl control, and is not wasted spark.

Can you see what color the wires are at the coil? Can you see the wire colors at the LJA1450AF? If so you could tell which wires are the primary wires and which are the igniter wires. If you can find the igniter wires, you can then drive it with Frankenso.

I suggest you keep the OEM igniter. Most coil near plug and traditional coils have a primary voltage around 350V to 450V, with performance perhaps as high as 550V. The igniter knows what voltage the coil can sustain, and will clamp the voltage at a safe level. If you use a 450V clamping igniter, with a 350V coil, you'll have problems hidden underneath. However you won't know that until your secondary voltage goes up for some reason, like plug gap to big, or something like that. AKA you coil is around a 100X multiplier, so aprox 400V turns into aprox 40,000V, which also is aprox 40 thousands gap. So if you gap your plugs at 30 thousands, you're secondary voltage will be about 30,000V, and primary will be around 300V. So you coil would be OK, and your igniter clamp would not be activated. However lets say you dwell is to long, and it causes a spark that is to hot. It would likely burn you spark gap a bit lager after the first couple thousand miles. Lets say that makes your gap 40 thousands, and now your voltages are 40,000V and 400V. Your still not clamping and you'll likely fry your coil, as the coil will start to arc internally. As well coil on plug like this likely has some odd voltages. Typically coil on plug is CDI, so there are going to be lots of funny oddities. I could not combine EDIS with these coil on plug's. Your asking for problems if you do.

However these issues all goes away if you use the OEM igniter with the OEM coil. I would not try to combine EDIS and this coil system. There are many non-published specs and they probably won't combine well. If you try it I would at minimum find someone who as done it and learn from their experience.

[V8Volvo245]

I suggested going wasted spark if it made things easier, not that Jaguar did it as stock. It's not unheard of in production vehicles, though. Renault, which you are lucky enough not get over there (but are a large proportion of the market here & are utter shite), use wasted spark on their COP setups.

I have yet to strip the Jag down, but will be pleasantly surprised if it has a separate igniter box rather than having the igniter built into the ecu. I'll see if I can find out, though

[kb1gtt]

If it doesn't have a separate igniter box, you could always try the J701. They are fairly low cost and fairly easy to find. I believe they are about a 350V clamp voltage, so typically safe for most coil near plug and traditional coils. If it doesn't work, then at least they are fairly low cost.

I have a pencil schematic found at the below link. Also note that these igniter boxes typically make lots of heat, and will need to be mounted on a good heat sink, like a bar of aluminium. My fear with the coil on plug like this, is that they typically have different amps and different clamping voltages. Those coils are small but deliver the same spark energy because they don't store the inductive energy via magnetic field like a normal coil. They instead rely on high amps on the primary, usually delivered via capacators, which then bumps up the secondary amps just like how your wall wart steps down from 220V to 24V. Those coil on plugs are a different beast than your traditional coils. I'm not sure a J701 will work. I suspect you will need a CDI igniter, and I suspect the OEM jag is a CDI device.
https://rusefi.com/wiki/index.php?title=Manual:Hardware#J701_NEON_engine_schematics

Back in the high school days, I had a friend who managed to get a Renault. I guess they made an attempt around the late 70's to mid 80's to sell in the states. It was messed up, the wheels on the passenger side were about 2 inches (50MM) closer together than on the driver side. That thing was a POS. It caught fire once, which we put out with sand. It was an OEM non-damaged wire, which had the wrong OEM fuse. It was simply garbage design.

Is there any chance you can find a coil on plug which includes the igniter, and physically fits the engine? That would likely be the easiest and most reliable solution. AKA if you external jag igniter breaks, that looks to be very expensive and reasonably un-common. So you might also have trouble obtaining the igniter if it comes to that. However there are many coil on plug's out there which are likely to have a good long service life. You might want to consider looking for a different coil on plug option. If worst comes to worst, then coil near plug is always an option, but those coil packs cost a bit more money.

[AndreyB]

If it doesn't have a separate igniter box, you could always try the J701.

Toyota igniter 89621-33020 like on https://rusefi.com//wiki/index.php?title=Manual:Hardware_Ignition#External_Igniter
It's the same thing but 6 channels which would keep things more compact in case of your 8 cylinders.

[V8Volvo245]

If it doesn't have a separate igniter box, you could always try the J701.

Toyota igniter 89621-33020 like on https://rusefi.com//wiki/index.php?title=Manual:Hardware_Ignition#External_Igniter
It's the same thing but 6 channels which would keep things more compact in case of your 8 cylinders.

That igniter seems very common over there, but is impossible to find here. Next time I've got some time off I'll try and have a dig around and see how any modules and ecus I can find in the Jag

[AndreyB]

Toyota igniter 89621-33020 like on https://rusefi.com//wiki/index.php?title=Manual:Hardware_Ignition#External_Igniter

That igniter seems very common over there, but is impossible to find here

Toyota igniter 89621-33020 - Lexus ES300 94-96, Camry V6 92-96

Similar thing Bosch 0227100211 - VW Audi 97- 05

There must be something in a wrecking yard.

[V8Volvo245]

Managed to find and download the factory workshop manual and thankfully the Jag has two separate ignition modules- one for each bank or cylinders. They're not too seriously hidden, either, which is a bonus.

Well, that's one bullet dodged......

[kb1gtt]

Cool. Do you have schematics for them? I wonder what the wires in and wires out might be. I suspect they are simple controls, but EDIS is a ford thing and I understand Jag is a ford thing, so who knows if they added some extra garbage. Any how if you have a schematic, I could offer some help in figuring out if there are other items of concern in the control signals.

[V8Volvo245]

I do, in the workshop manual. I'll try and screenshot the pages after work tomorrow

[V8Volvo245]

[kb1gtt]

Wow photobucket still works, and holly commercial clicking. I had to click like 30 advertisements just to see the image. Can I get you to attach that image to the thread? Also a higher resolution picture would be handy if you have it. Perhaps you could simply attache the PDF. I see that PDF note, so I'm assuming it's a PDF.

That coil looks funky. I see 2 coils with a diode, all sitting on top of the spark plug.

This looks good. It appears you have 4 control signals, and one return signal. The key now will be to figure out if it's 12V control, 5V control or other, and which one is the return signal. Is there any chance you happen to have a scope. How about a multi meter? I'm trying to figure out what tools you have so I can suggest a way to isolate which wires are which. What do you have for electrical tools?

[V8Volvo245]

I have three auto ranging multimeters and one of my next purchases will be a scope, although I'm torn between a used one and one off Alibaba for cheap.

[kb1gtt]

These Rigol's are nice, and not crazy expensive. The below 4 channels is about $350.
https://www.google.com/search?q=rigol+ds1054z&rlz=1C1AOHY_enUS708US709&source=lnms&tbm=shop&sa=X&ved=0ahUKEwi2yKuw_77YAhUMMt8KHaVYB34Q_AUICigB&biw=1280&bih=642#spd=16193568055678945282

[V8Volvo245]

I'll see what I can get used!

[V8Volvo245]

Wow photobucket still works, and holly commercial clicking. I had to click like 30 advertisements just to see the image. Can I get you to attach that image to the thread? Also a higher resolution picture would be handy if you have it. Perhaps you could simply attache the PDF. I see that PDF note, so I'm assuming it's a PDF

So what are all the cool kids using for their free photo sharing? Can't attach the whole manual as it's 63mb. Better fire up the PC if I'm to attach the previous pic to the thread as I can't seem to do it on my tablet

[kb1gtt]

Sync, or github might work for this. I'm not sure there are any good picture sharing services any more.

[AndreyB]

Can't attach the whole manual as it's 63mb.

https://thepiratebay.org/ ?

[V8Volvo245]

Can't attach the whole manual as it's 63mb.

https://thepiratebay.org/ ?

Easier to share the original link: http://www.mediafire.com/file/u90y6a6r5nsgs6m/XJ-X308_Workshop_Manual.pdf

[V8Volvo245]

Wow photobucket still works, and holly commercial clicking. I had to click like 30 advertisements just to see the image. Can I get you to attach that image to the thread? Also a higher resolution picture would be handy if you have it. Perhaps you could simply attache the PDF. I see that PDF note, so I'm assuming it's a PDF.

Should be attached now

Ignition module diagram XJR.jpg

[kb1gtt]

I see for each bank, you have LG? at 4X, and one SG. So that should make is fairly easy to identify which is the SiGnal. After you cut the SG wire, you'll want to measure the internal ohms of the OEM ECU. When you find it and get close to this, I can offer some guidance.

Hmmm, I don't see wire colors. I guess you'll have to identify them based on which pin the wire is connected to. If you disconnect the connector, do you see a pin number on either side of the shell? I'm not sure what pin they might have called 1, 2, 3, etc.

[V8Volvo245]

I need to locate the ecu and work out which wire does what, r find the legend for wiring colours. Trouble is the manual is around 2000 pages and, being a PDF, is a pain in the arse to navigate. I'll get there in the end, though, so it shouldn't be a problem.