Ugh, my first real problem, Even-Numbered Misfires RESOLVED
 

I guess it was bound to happen, but I was finally let-down by my XKR at 64,000 miles. I was tooling down the freeway and did a quick sprint to get in front of an idiot who was barely doing the speed limit in the fast lane...... and "RESTRICTED PERFORMANCE" popped up on the dash. Dammit! I was already moving pretty good, but decided to return home anyway. I moved right to get to an exit........ and it had the power of an Audi Sedan (barely moved) so I sort of coasted/crawled to the nearest exit and Red Light. Dang, it barely idled! I got turned around but it died once right before the Entrance ramp. I did limp it home and it died two feet from inside my garage, but started again and heaved in.

DAMMIT!

So anyway, I connected my Bluetooth and Torque..... All the P-codes (P030) for Cylinders 2,4,6 & 8, plus generic and Fuel Pump Secondary Circuit High.
Of course my first thought was CLOGGED CAT!, but would that really affect it on tick-over? Why would it work perfectly perfect one second and then clog immediately?
There was also a strong smell of gasoline when I shut it down.

Sooooo......... now I'm charging up the car battery and my Laptop with SDD battery. Having not really used SDD when there was a problem as I've never HAD a problem, guess I'll find out how much better it is than a generic code reader.

DAMMIT AGAIN!

That sucks... Keep us updated...

Fuel injector rail issue perhaps. That's happened a few times with the 5.0s I believe.

Well if all you got are the P0300, P0302, P0304, P0306, P0308, then you choices are few. Typically, Cam Position Sensor or Cat as you first thought, though a Cat @ 64k isn't likely. CPS failure on bank 2 should also throw P0390, P0391 and Catalytic converter should also throw P0430 on bank 2.

It would be odd that only the even bank would be affected by fuel system or air intake wouldn't it?

I have come to the sad conclusion that SDD is completely and utterly useless for diagnosing ANY problem in an XKR. It gets to the Loading Recommended Candidates in the DTC tab, then it goes to the Unknown Vehicle Specification in the Recommendation tab.... for a question of Restraints Occupant Classification System with two choices; Fitted and Not Fitted.
THERE IS NO WAY PAST THAT PAGE!!!@!!!!!! Regardless of what I select (even nothing) it goes in a frikkin' loop! I tried for an hour to make something happen, and NOTHING WORKS. I started several New Sessions, same thing. I restarted every MoFo thing I could restart; SAME STUPID THING.
I tried going several other routes..... Comes back to that SAME THING.
I can NOT read a damned DTC ONE on this stupid car with stupid SDD!!!!!

Guess I rely on my $8 Bluetooth OBD2 reader and Torque.

Yep the engine codes (I think) are all standard and not specific to Jaguar so the P codes you have should suffice. They all end in - OO, so no Jag specific detail and no more drill down

Got none of those, just the misfires and Fuel High thing.
Maybe a wire came loose somewhere (yeah right) and everything will be hunky-dory in a minute. Not likely.

I feel like crap today anyway, got a sickness from the Grand Daughter. Think I'll go take a nap.

I got lucky once. Wife calls, CEL is on. Ran codes, it was MAF related (forgot the code, I made a thread here somewhere)... Opened hood, followed intake to find MAF and noticed a wire sticking out of a connector on the left side harness that is attached to the tubing from the air filter. Hmm. the wire on the right side is connected...... Soldered it up, code gone.

Good luck!!

Sounds exactly like what happened with my 2011 XJL Supercharged. Hit the gas hard going up hill and blew the injectors on the driver's side. Got misfire codes on cylinders 2, 4, 6, and 8.

Hmmmm........... something I can check quickly!
So where are these injectors? I can build any analog V8 in my sleep, and also anything up to about 2005. These compact monstrosities have me searching for things I never knew existed. I know Injectors of course, just not where and what they look like now. Probably something weird. AND probably under the stupid intercoolers or blower.

I think the strong smell of unburned gas on shut down is an indication that fuel injectors are "working", but there is no ignition. Don't think it is a coil failure - it would be very rare for four coils to fail simultaneously. Same logic with spark plugs. I would concentrate next on the electrical path to the coils.

Big question for the group...

What happens when the exhaust passage partially blocks?

Answer. As the exhaust passage pressure increases the burnt gas pressure in the combustion chamber becomes higher than the intake charge. Once the intake charge is diluted enough with burnt gas it won't fire. Eventually the engine sees that the ignition pulses are not contributing to the RPM and throws a misfire code.

Think fire triangle, fuel, oxygen and heat. You have fuel and heat but not enough oxygen to light the fire.

A distinct possibility are stuck injectors, which would account for the raw fuel odour.

The injectors are positioned below the intercoolers on the supercharged 5.0 litre unit.

Isn't the CPS (crank position sensor) the main culprit in the ignition sequence. If fuel smell I don't think it's in the injectors so you would need to check if you get a signal to the coils. Just thinking out loud

Cee Jay,
This sounds exactly like what has happened to my car on two occasions. Started misfiring horribly, stalling, smell of gasoline unburnt. Each time, my indie reflashed the ECU and did nothing else, and everything returned to normal. About a month ago, it happened again as I was getting on the freeway. I proceeded to the next exit to get off the freeway, and all of a sudden it returned to normal. I took it in to my indie the next day without any problems, and he couldn't get it to misbehave. Good luck with diagnosing it. We still don't know what happened.

Whelp, between naps I did research a bit in the Service Manual plus I used member recommendations and I have come to one more-than-likely cause........ A clogged Cat.

Injectors all going fooey at one instant isn't likely, and I don't think it'd run on only one bank, even as miserably as it did.
Same for the coils, all four at one instant?
A small update since I'm at this point.... I tried to start it after I did a hard reset AFTER I got the codes (Restricted Performance still there) and SDD failed me miserably... nothing but one continuous crank with zero fires of any sort. Not even a hiccup. I didn't smell any excess fuel.

So anyway... the 'test' for a clogged cat is to have it running and check for flow and temps before and after the cat. NOPE! Can't do that if it won't start. Plus I have an X-pipe.

THEREFORE, how would one go about testing for a clogged cat without the engine running? AND, why would an engine not even fire once if a cat was clogged?
I would rather not fight to get to the coils and injectors to test them before I check for the Supposed most likely check.
Plus, if it IS the Cat, I missed the Federal Warranty period by 2-1/2 months.

Maybe I'm getting more screwed the further I delve.

If it won't fire at all now and you can't smell fuel and you got Fuel Pump Secondary Circuit High could this mean that your fuel pump or fuel pump module are stuffed?

This doesn't sound like clogged cats to me. My old 2008 XJR suffered from clogged cats. The only symptons I had was a recurring EML indicating cats inefficiency for 2 years, with an eventual inability of the car to get passed 100mph on the motorway, That's when I cracked and bought new cats. The originals were almost solid with crud in the honeycomb. This was at 100k miles approx.

I suppose it's possibly that one of your cats has 'collapsed' internally and the gas cannot flow through a collapsed honeycomb, but I would have thought there's many other likely causes before getting to that.

To check for cat problems remove the upstream o2 and inject pressurized air into the pipe using the rag wrapped around the air nozzle trick to seal the hole. Check flow at the tips or back pressure when you unhook the air from the o2 bung. The engine will seal the upstream end.

Sadly with the latest updates I'm leaning more towards your SDD troubleshooting attempt bricked your car.

Cee Jay,

Have you performed a Hard Reset? I would start with that and then see if it will run again. Simple and easy to do.

Fingers Crossed for ya,

Dave