I did a cooling system update as preventative maintenance and replaced the valve cover gaskets on my 2013 XJL 5.0 SC. Of course, I had to remove the injectors and replace the fuel rail and Teflon seals as part of the valve cover service. After reassembly, the car wouldn't start. I probably had to crank it for a total of over 2 minutes to finally get the car to crank. When it did, the engine would stumble, stall, and barely idle with an eggy smell out of the exhaust. It feels like the car cannot create or maintain fuel pressure and shows the following DTCs:

-P0087- Fuel rail pressure too low
P0191- Fuel rail pressure sensor range/performance
-P00C6 Fuel rail pressure too low- engine cranking
-P0183- Fuel temp sensor A circuit high input
-P053F Cold start low fuel pressure
-P228F Fuel pressure regulator 1 too high- exceeded learning limits

I ran the Fuel System tests in SDD. The high pressure fuel rail sensor is only reporting 55-60psi at idle, which seems to suggest a high pressure fuel pump issue. I used the SDD utility to shut off one or both of the HPFPs while the car is running and there was no change in the symptoms. It feels like the HPFPs are not doing anything at all- but the car was running fine before I drove it into the garage and I didn't touch the HPFPs at all as part of my service? Did dry cranking them kill them?

I performed the following diagnostic tests on the fuel rail pressure sensor itself:
1. Ensured fuel rail pressure sensor receives 5 volts with ignition on.
2. Fuel rail pressure sensor has continuity to ground and has continuity between all pins between the sensor itself and the harness pins at the ECM. So the ECM has good connection with the fuel rail pressure sensor and does report pressure (~400kpa or 55-60psi) at idle with engine running which is supplied by the in-tank fuel pump.
3. Replaced fuel rail pressure sensor with no change or improvement.

I'm also smelling high sulfur content in the exhaust which suggests I may have an injector dumping fuel into the exhaust. That may explain the engine not being able to hold fuel pressure- but again, the car drove into the garage with no issues. And once it finally starts it will hold idle fairly steady- it doesn't seem like it would do this with an injector wide open. What gives?

 

I hate to throw parts at a car, but I need it back on the road and there's no easy way to troubleshoot fuel pressure problems on the high side without expensive diagnostic equipment that I don't have access to.

I'm going to try replacing the HPFPs this weekend as they're likely due for replacement anyways at 120K miles. If that doesn't solve the issue, I'll replace the injectors. Does anyone else have any insight on this issue?

 

I don't see why one of the HPFPs would fail, much less both.
I'd suspect one (or maybe more) of the injectors.
If you could pull the spark plugs & look into the cylinders to get an idea if one (or more) are wet with gas or at least see if the plug is wet and smells of gas, that would be a start.
And to get around until you get it sorted out it's a good time to get a rental car (maybe $35 or so a day). that'll help take the overall stress down while you're dealing with it.

 

I do have other cars to drive, I just miss the power and comfort of my Jaaag!

I did pull one of the spark plugs and it looked fine, in addition the car will eventually settle to idle without misfiring. I would think it would not be able to idle at all if one or more cylinders were totally flooded? Perhaps I will pull a few more plugs and see if they are black and sooty.

I think my next troubleshooting step is to ensure continuity between the pressure regulators (bleed valves) on the high pressure fuel pumps themselves and the ECM. If I pinched any wires while performing the cooling system update, perhaps that is relevant. The bleed valves on the fuel pumps will default to the open position to return fuel to the inlet side of the pump if they experience power loss or failure, meaning the HPFPs would not send any pressure downstream.

I find coincidental failures very hard to believe. I've replaced HPFPs on others makes of vehicles and have never killed them while priming them with fuel after replacement.

 

I figured out my issue and thought I'd share my stupidity with you all.

The AJ133 runs a returnless fuel system with one supply line coming from the tank. Right next to that fuel line is a vacuum line that runs to the throttle body. In Jaguar's infinite wisdom, they decided to make the connectors look exactly the same and be compatible with each other.



I accidentally switched the lines around. So my HPFPs were receiving only air, and the vacuum line was receiving a large volume of gasoline straight from the fuel pump. It's amazing my car was able to start at all, but it was essentially running like a mid-80s throttle-body injected General Motors car, which explains why my car would almost idle normally but would stall when I stabbed the throttle. Here's where that vacuum line dumps- right into the throttle body! Oh well. At least the gasoline flowing through my supercharger probably cleaned out the intercooler fins and the back of the intake valves!



Car is back together and running well after a fresh oil change.

 

Great troubleshooting!
Your picture shows a connection I have yet to figure out how to remove? The one right next to it has a conventional plastic ring you squeeze to remove. I had no problem with that one.
The one your finder is pointing too. Did you take it off?
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I did. There's a small area on the bottom flange of the connector that you push in, then push down on the connector and it will pull up. If you poke around the connector lightly with a screwdriver you will be able to see how it works.

 

OK thanks for the help. I did see and push on the tab but tried to pull it off. I think my error was I need to push in as you posted BEFORE I attempt to pull it off.
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Thanks for contributing that.
This question comes up occasionally, and your post will probably help at least some of us.
This connection has been a headache for me - I never have been able to release it.
When I replaced the valve cover gaskets on the XJ and even the head gaskets on the Range Rover (with the same engine) I ended up just leaving it connected & working around it.

 

Hey Mark me too! I was afraid I would beak it if I kept messing with it! i just left it connected and swiveled it around as needed.
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Well I am stupid for sure!
This was too easy and after another look it popped right off.




The release tab is hidden by the large vacuum connection that is right next to the little one. I kept poking the openings I could see but they did not do anything.
After I took the larger diameter vacuum hose off I could see the tab. That's not necessary to remove the small hose once you know where to press.
Thanks for the advice!
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That's a different line than I was thinking about.
Our XJ is an NA so no supercharger lines involved.
The one I have a hard time with is the low pressure fuel line with the red tab.

 

Gently pry the red clip out of the side of the female connector, it is shaped like a U and will disengage with the connector on both sides. Then, push the male connector into the female connector and there is another tab inside the connector you need to squeeze to release the male connector. It’s a bit fiddly and do not use significant force because it seems no one can find the part number for this low pressure fuel line> HPFP supply hardline.

 

It does seem to be a bane of a few of us, you're being polite when you call it fiddly. And it is a phantom part.
If I remember to call the Annapolis Jaguar online parts guys, they're great at finding parts that aren't included on their online catalog since they have the fuller catalog in their reach. They're very helpful.

 

Well, this saga is not over unfortunately. I’ve been driving my car all week and driving it hard and it’s been flawless, but I last night I was driving and accelerated to make a pass, and the car hiccuped, threw a check engine light, and entered limp home mode. I could not give any big throttle inputs, but it maintained highway speed all the way home.

Upon getting home I checked the codes in SDD. P0192 fuel rail sensor circuit and lean condition off idle bank 1 and bank 2.

P0192 usually indicates an issue with the fuel pressure sensor circuitry itself. So either running dry for ~10 minutes when my hoses were incorrectly routed actually did kill my fuel pumps or the fuel rail pressure sensor I preventively replaced has gone bad. I think the latter might be a possibility given some research, but I’m going to check my wiring first. There is also a small chance I incidentally spread out the pins on the PCM harness while checking the circuits the first time, but I’d think that would have shown its head before now.

I ran the SDD HPFP diagnosis facility and there was no difference in sound or performance when I turned either of the pumps on or off. So either both pumps died at the same time or neither of them is dead and the replacement fuel pressure sensor has internally shorted. SDD reported 0v and 0KPa from the high pressure sensor even at idle, so I’m hoping this is the case and I can throw my old sensor back in there and get it running again.

 

My car has seemed to heal itself. Went to start diagnostic this morning and the codes were gone. I used the SDD utility to shutoff either HPFP and both of them were able to maintain the requested pressure. So there must have been some small electrical hiccup that caused the limp mode, otherwise I have no explanation…

 

Thanks for reporting back and yes that is a puzzle?
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Hasn't happened since, and I've put about 100 miles on the car since then. I am showing a DTC P0497, so I think the gasoline hose misrouting killed my evap system purge valve. I'll be replacing that this week just to get rid of the CEL but haven't noticed any drivability concerns other than that.

 

Evap purge valve replaced with part# LR010749, cleared the codes and it hasn't come back.

 

Wanted to come back and say thanks for your pictures labeling the vacuum and fuel lines. I will borrow that and use the vacuum one to inject some back of the intake valve cleaner into the engine. That blue vacuum fitting is easy to separate so I can get access to the vacuum on the drivers side of the engine. I wanted that so I can sit in the drivers seat and operate the throttle while spraying the cleaner.

The previous suggestion to use the PB vacuum line puts the cleaner in one side of the engine. So not even cleaning and the cylinders closest to the vacuum port get the most benefit. I am hoping by injecting the cleaner in the front of the engine the cleaner will treat all 8 cylinders.
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