Also the cylinders you named are on bank 1 and 2. When my head gasket failed that's exactly what was misfiring. But I confirmed it with a coolant reservoir tests and because quite literally it was leaking coolant and oil from the block

 

I bought the car like this, in your area by the way (Washington, DC). It came with a spare computer, which makes me think someone was trying to figure out the issue before. When I received it, the HPFP timing was completely off, and the engine wouldn’t stay running. After replacing both HPFPs and adjusting the timing, these are the codes I’m getting now.

All I know is that the car passed emissions less than a year ago and about 1,000 miles ago. It currently has 63k miles on it.

The cylinder numbers I mentioned are all on Bank 2. I know that sounds incorrect, but I confirmed it by unplugging the injector and checking SDD. I’m aware that most diagrams (but not all) show cylinders 5 and 7 as Bank 1, but that’s not what I observed in this case.

 

Bank 1 is odd numbers, Bank 2 is the even numbers. It's weird but I confirmed it when I unplugged the coils and we have the same engine, my mother also has a ranger Rover autobiography 2013 which I work on. So unless you're saying you're engine was rebuilt and they plugged the wires incorrectly on yours or mine that's kind of odd.

That might be something worth confirming

 

my is 2015 Land Rover Range Rover Autobiography on short wheel base(L405).

Im planning to swap injectors from bank 1 to bank 2 and see if that makes any difference.

Will also take couple pictures of the SDD screen with the misfire data.

 

Swapping injectors on this engine isn't as easy as you may think. Trust me. Did them kn my xj and just straight up replaced them (costing close to 600$ no change)

You have redo the nylon seal if you remove and reinstall

 

I already replaced all injectors on bank 2 with no change to misfire. Now I want to swap them to completely roll out the injectors fail. I’ve seen a lot of complains about fake injectors. I ordered these from RockAuto. All new in boxes. However, 2 of them were dated 2023, the other 2 were 2025. These 2025 had no plastic cups on them. Suspicious…

 

Long thread with much work done. Any chance these miss fires might be related to carbon buildup on the back side of the intake valves?
I ask because on a cold start I feel my car is a bit "lumpy" at idle sorta like when the PCV diaphragms were split and I had a vacuum leak. No codes are set and when warm it's very smooth.

Several posts in other threads have mentioned these slight and weak miss fires on a cold start as possibly due to carbon build up.
Have you looked at the back side of the valves?
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No, I haven’t but I will. Need to buy a scope camera.
my misfire is bad and check is blinking on coldstart. After about 1 min running it’s getting better and almost no misfire, no checkengine. After 20-30 miles drive error on bank 2 cat efficiency below threshold. Removed bank 2 cat and started the engine - no improvement, even felt worse.
took a picture of the cat from inside.




l

 

Somewhere in the thread I also showed my intake valves but yeah they were clean as a whistle as the engine was rebuilt.

That's why I held off saying anything else in the forum till I dismantle the supercharger myself

 

if misfire count builds at the 9-1100rpm range 100% chance it’s half a tooth off. totally opposed bank to bank trims already put a bunch of nails in the coffin now that i re read this post.

if you use the cam lock tool wrong or tool is sloppy it will happen. just had to fix two of these messed up jobs recently.

 

I couldn’t fit the tool perfectly. It was always bit of. The chain might have stretched.
here is the way I have it, a bit advanced, less than half tooth.

 

i’m talking about this guy’s post not your aux shaft problems.

 

If you're referring to me, the misfire doesn't count or register at low rpm. Once you get on the gas or increase rpm they will start counting.

But let's say yes, the shop messed up the timing, what's a way to confirm, find and correct. Do I need to drop the engine back or or take off the supercharger, fuel rail, plugs, coils and valve cover?

I have no timing codes, or anything else.

 

1. Remove the engine lower cover.
2. Drain the oil.
3. Remove the vacuum pump (2 bolts).
4. Turn the engine by hand and set to DTC using the flywheel timing tool.
5. Install the HPFP timing tool. Ideally, it should fit without any force. (I’m pretty sure if it’s off just a bit it is still within tolerance. There is no way to set it perfectly if your chain is a bit stretched.)
6. Pay attention to the label - it should be on the top , as shown in my picture above.

You might better replace the vacuum pump gasket since you already there .
you won’t have timing codes with hpfp timing off. But you most likely would have rail pressure codes.

 

Gotcha. That would probably be a task I do in October when I'm out of training. Currently in a 6am to 10pm schedule for this musical military (we call it)

But just for context the engine was fully rebuilt, with a whole bunch of things changed while dismantled fixing the head and resurfacing. So if hpfp is possible I don't doubt it. But only codes that show is inconsistent misfire followed by cylinder numbers

 

Update: since the idea of the high pressure fuel pumps I went back into the car today (worked on some things) then went ahead and did some data streaming in the sdd and found that the fuel pressure reads 900-950 psi. And when revved reaches only maybe 1080 psi max and the desired psi according to JLR and sdd is 1450psi.

I'm starting to wonder if what I thought was the coupler was the fuel pump on bank 2. But I now speculate if it's actually the fuel pump that's miseated, worn or just bad.

I also checked timing via sdd for the actual valve and the absolute. They're the same between bank 1 and bank 2. They don't go anywhere beyond a 1-2 degree difference at all times.


My next step is to replace the fuel pump on that side with a new tappet after I do some researching.

 

Not sure where SDD gets that number but I think your way low on fuel pressure?

From the Jaguar 5 litre V8-Technical Introduction. It states;



Also;



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Possibly but when the engine is at idle speed the fuel pressure is quoted as approximately 435psi (30bar), and 2176psi (130bar) at full load. It also states that the High Pressure Sensor measurement is used as input to deliver the correct quantity of fuel. (p50 of 118, of document quoted in post #97 above)

 

435psi at idle? That sounds extremely low. At idle on this xj is around 900psi.

What I plan to do is further compare the numbers to my mothers landrover sport 2013 with the 5.0 supercharged engine (exact same engine) and her's is completely healthy (I work on hers from time to time).

But according to Sdd, the timing for intake and exhaust ports are all good numbers so it's not that, and when I viewed her data as well it was the same range of numbers in degrees.

It's either the injectors I didn't replace they failed to replace the seal or refit them since those are the only ones I haven't replaced or touched(original from 2012), or they improperly installed the hpfp. Or it's bad.

But I believe now I should look into fuel delivery.

Because the compression numbers are adequate so it's not mechanically the engine.

 

Yes at idle it's not 2176 psi. But the manual clearly states that for starting the fuel pressure is 2176 psi then it drops back when the engine starts.

Good idea to check that LR fuel pressure. Should be the same as your engine.
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