Today I've had the issue of the P1368 Ignition System Fail Group 2 which indicates the left bank ignition amplifier is bad - misfires recorded for 2,3,5,8 primary/secondary coil circuit failures P352/P0353/P0355/P0358 and a coil 8 P0308 DTC. I'm sure all the other codes I've not listed are secondary to the misfire issues causing other faults

As P1368 disables fueling, injectors, fuel trims and feedback of the O2 closed loop, I think the bank Amplifier should be the first suspect or coil 8.

I will check the fuel injectors - DPO/DPM actually glued on the connectors to all eight injectors so a new set of connectors is in order and I'll test the injectors during that process.

But the root question, where is the Left Bank Ignition Amplifier located?

 

Reviewing the 2005 Electrical Schematics, there are no separate left or right bank ignition amplifiers.

The coils and injectors are driven directly from the ECM itself, only a capacitor / RC network is mounted externally to take the trigger "ringing" off the pulses .

Once again the programmers of the Engine Management system show their total incompetence in performing even the slightest reliable and meaningful diagnostics on any Jaguar engine since moving from points and carburetors. As a controls systems professional that really sticks in my craw when these pimplefaced IT programmers think they know anything about engine management or control of any physical control function, argh!!

At least with IDS I can have a look at the path of DTC's, rule out the misinformation triggered from 2nd or 3rd layer issues, and do some pinpoint diagnostics. Anyone have an AMM with full cable set for sale?

 

I did omit to mention that when the misfire started I smelled phenolic electronics circuit board burning - being an engineer recognize those little details.

So coupled with the smell, what is on the engine with a circuit board, and the IDS after ruling out the secondary codes, bingo the most difficult ignition coil to access and remove on a XJ8 X350 is of course #8. And was it ever stuck in there plastic was really melted holding the coil in its hole.
.
Anyway, fairly common part for Jaguar, Land Rover, Ford common series engines.

Is this typical of these type of coils at 78k miles? Odd, there is one number the coil, "J16"

 

#6 coil (right) is good), number #8 coil (left) is bad, very bad

 

Great information!
Griff

 

The rear coils were swollen on mine, but nothing when compared to yours.
Was replacing the spark plugs when i noticed the rear coils were tighter than the rest.
Made sense to me that the swelling would only get worse, so i replaced them all.
With 8 Chinese knock offs for less than $100 delivered.
They work great with the old ones in the trunk, with a reader in the glove box.

 

I will compare my coil purchase supposedly from "A-Premium", whoever that manufacturer actually is, out of the apparent dozen or so more "brands" of coils. At least they are sourced within the USA and warranted for a full year with apparent reputable warranty support.

I find it very interesting there are over a dozen "manufacturers" of this one type of coil - I would believe 4 maybe 5 manufacturers and the rest are repackaged sort of like "County" brand in the UK just takes other manufactured parts and puts them in a "County" box or bag with no quality assurance or quality control applied taking the lowest cost parts they can find to repackage.

It looks to me the coil positions of the #5 & #7 and #6 & # 8 coils are in an area pushed back into the firewall and then with a metal cowl directly over top of those coils with engine bay insulation with little or no airflow, a lot of heat gets trapped there especially with the plastic coil covers in place to trap even more heat and no heat sink for the electronics to wick away heat.

Coils / electronics do not like excessive heat and with no airflow past or around them and those coils are in a perfect place to heat soak in a hot location.

Engines generate quite a lot of heat and most plastics and rubber must be specifically designed for the temperatures plus the operating temperatures of electronics in the most extreme areas of the actual application.
This engine is used in a lot of different engine bays with different airflows.

I have seen several people changing coils that have melted in those locations and I am not convinced it is an OEM manufacture vs 3rd party manufacturer issue of the coil manufacture as of yet - rather a location where more heat builds up.

The more I look at it I am seeing it as a location that receives lots of heat that it not being moved away from the electronics causing the problem.

Here is what I suspect was trapping even more heat:


Firewall sound / head padding hanging down on top of the #8 coil position most likely blocked airflow and trapped heat. Probably a DPM when the transmission was removed prior to my purchase.


The culprit! Sound/heat insulation on the engine side of the brake booster housing totally turning to dust. I'll use it as a rough template for some more modern firewall insulation.



I'll clean out and cover this area with some modern adhesive backed firewall sound/heat insulation.

Cheers!

 

that's a cheap aftermarket coil. buy good used ones from an 09+ XF or range rover 4.2\4.4. they switched from denso to unmarked hitachi with metal tube at that point. will have a ford assigned part number, 6R83 something something something

 

SORRY IT'S TAKEN ME SO LONG TO GET BACK TO THIS POST, I HAVE UPDATES

IT WAS THE COILS!!!!!!!!!!!

At first I couldn't believe it. I replaced all 8 coils in 2019 when the original Nippondenso coils started going bad (I also replaced the spark plugs with the correct NGK's.....more on this later). I bought the Asian-made Bremi coils. Within 6 months, I had to send 2 of them back for warranty replacement. Well believe it or not, when the problems started that I explained in this post, it was actually several of the bremi coils going bad at the same time, so switching them around did no good and even replacing 2 with a pair of 2 known good coils didn't help because at least one more was going bad at the same time. I finally broke down and bought 8 Delphi coils from Rockauto and the car began running correctly (The Delphi's from Rockauto have a 3 yr/36,000 mile warranty).

Now about the spark plugs. I replaced them at the same time as the coils with a set of the original spec part NGK IFR5N10...or so I thought. When I began troubleshooting this issue, I removed the replacement spark plugs and compared them to the originals, which I had saved. They didn't look the same. The center electrode on the originals is thin and highly machined, the replacements have a shorter, fatter, less finely machined center electrode. So I did research on these spark plugs. Turns out this NGK 7866 IFR5N-10 Laser Iridium Spark Plug is supposed to have 5k ohm resistance value. The replacement NGK 7866 IFR5N-10 that I bought from a seller on ebay... did not have 5K resistance. I was having a hard time getting any kind of value at all from any of the 8 replacement spark plugs. So I put the originals back in, they all tested 4-5k ohms. They are rated for 100k miles anyway and they were replaced at about 60k miles, so they should last as long as the coils. I'm guessing these fake NGK spark plugs played a part in the untimely demise of the Bremi replacement coils... Lesson learned.

Anyway, sorry it took so long to post these updates, I had a little health trouble right after this Jag issue. Now I'm having a suspension issue so I'm back on the forum trolling, reading and updating.