@ RoverJoe - I played around with the scanner after work today with the car idling. Here is what I have as preliminary readings from what I can discern on the data. All of these are at idle.

Fuel pump control b (low pressure) - 549kPa
Fuel rail pressure - 3240 kPa
Fuel rail pressure - 3150 kPa

The rail pressure values increase when I give it more gas. Did not have time to play around with it more and do not have values at 4K rpm which is the max that the car will rev to if in park. Haven't figured out a way to generate graphs in the scanner yet.

As a general update, car seemed to run fine today, both to and from work as well as a couple of short runs for lunch and gas. Started up first attempt at all times. Ran like it has in the past including a seat of the pants throttle response feel and overall feel when driving around town and cruising. Keeping my fingers crossed for now.

 

5.5 bar on the low side looks good, the high side will move around as load increases, that i'm not too worried about right now. Gonna have to get it to break to find the problem unfortunately. If you get it to start and die, that's when I'd be curious to see that low pressure pump reading.

 

Thanks RoverJoe you Factory guys sure know all the details!

Sorry for a bit of off topic but your comments about the LP fuel pump and how the car monitors the pressures is interesting. After sending data logs to my tuner they found a fall off in the LP pump output and recommended that I install a fuel pump voltage booster. This was happening at higher engine speeds especially on longer pulls and 1/4 mile runs. He asked if I had any LP fuel pump codes because the car was borderline. I did not

I used one from VMP. Runs the pump at 18 VDC so the LP pump has full output at all times. I noticed nothing and the car is no faster after the install. It was simple to install. These are way common on the US muscle car side of things but not mentioned here on the forum.
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The newer cars have a 3 phase pump so added voltage is useless. All you're doing is overstressing the pump driver module as it has to switch the phases at a higher voltage all the time. They already overheat and get wonky at stock voltages.

The systems on these cars are controlled by the pressure sensor, so the pump is driven harder when the pressure isn't up to par, and then backed off. Voltage is not usually the limitation.

 

Allright, so the issue recurred again tonight, somewhat. Car ran fine yesterday and this morning. Started up just fine this morning on first crank - drove just fine to work (1 hr drive) - about 8 hours in the outdoors work parking lot - cranked up just fine on my return drive and came back home okay without any issues - car sat in the garage for about 2 hours - upon restart, car seemed to crank longer than normal to get started but it did start, no CEL - dropped kid off to soccer and then returned - car sat in garage for an hour - tried to start it to go pick up my kid - it "cranked" , then almost felt like it bogged down to almost a stall and die but i guess it "caught" and fired up without needing another crank - this is when the CEL came on - drove fine for the 30 mins that it takes to pick up my kid. Came back home and hooked up the scanner tool which registered 2 fault codes in the ECU section, listed below -

"P008A-84, State : pending, low pressure fuel system - pressure is too low." I do not know how to pull the kPa reading at the time that this code registered, but I may have seen somewhere around 90kPa for this module when I was toggling between screens.
"P00C6-00, State : permanent, fuel rail pressure too low - engine cranking. " Like above, I may have seen readings of around 900-940 kPa when toggling between screens but cannot confirm if these are when the code registered.

Once idling, the 3 kPa readings appear in about the same range that I mentioned earlier. While stationary, upon revving up to 4K rpm, the fuel pump control b remains around 550-590 kPa and the 2 fuel rail pressures jump to between 6000-6500 kPa.

Since the HPFP pumps are already replaced (and hoping that the tech did not mess up the press fittings of the fuel lines or anything else), I am assuming that the P00C6-00 is secondary to or downstream of the P008A-84 but I am no expert in this.

So, what am I looking at? A failing in-tank low pressure pump / sending unit replacement? something else? Really appreciate all help from y'all. If its of any help, once I got the codes read, I shut the car off, let it sit for about 10-15 minutes between each start and then started it up twice - started up just fine without hesitation.

 

Sounds like a low pressure pump side issue to me. Fits with your symptoms. Does your scanner show freeze frame data from the faults? It should show those pressures at the time of the fault setting.

 

I would also say that the low pressure pump is your problem, we have replaced several with the same symptoms. As far as a good independent goes in your area you might look up Jag Mac Garage and ask for Russell. We have referred customers there for years that have relocated from Oklahoma and had zero bad feedback from them.

 

Thanks a ton for your help and recommendation!! I will for sure check them out. I would also like input from folks on here if this is something that I can attempt on my own. From what I could read up on this, it appears that I do not have to drop the fuel tank for this? Access for this replacement is from under the rear seat ?? (which I already have off since I am trying to trace a rattling / possibly blown rear speaker). I would want to know the pitfalls of trying to attempt this on my own. Full disclosure, I failed in my attempt to replace the HPFP pumps on my own and needed to have the dealer do it (front pump seemed to be stuck on the spring and I just could not manouver enough from under the car to get the rear HPFP off). If the in-tank low pressure pump is less involving to replace with basic hand tools, then I can try to do it on my own. If it needs SDD assistance or special tools, then I might as well take it in.

Thanks again for your help and recommendation.

 

@RoverJoe as noted above, is this something that I can attempt on my own? or is it something that will need a SDD hookup for any specific procedures that are needed pre and post - for eg : pressure bleed prior and priming post replacement? Also, would you have a reliable source for parts? I used FCP Euro in the past both for my BMW as well as the recent HPFP pumps replacement. They do seem to have 2 items show up when searching for low pressure fuel pump for my specific car. There is a sending unit item that shows up, and a fuel pump but with vastly different prices. From the pictures, these appear to be the same part and at least their website lists both of these as compatible with the car. I do plan to call them and ask about the price difference.

Jaguar Fuel Pump - Eurospare C2D37814 - this one's listed at $ 283.99

Jaguar Fuel Tank Sending Unit - Delphi C2Z23190 - this one's listed at $ 980.99

While we are on the topic of replacement, since either me or the tech will be in there, are there any other preventative replacement that I need to get done - seals, fuel regulator/s, valves, sensors, etc?

 

You will need a special tool to properly remove the tank flange.

 

would you have a part number for this tool if its available for purchase?

 

Added the procedure. You can usually use a generic fuel tank locking ring tool, they may have one available for rental at your local auto parts store. I have removed many of them successfully using a hammer and large flat screwdriver or dull chisel, but the right tool makes it much less risky.

There isn't really anything else in there to replace, your pump/sender assembly should be largely complete when you get it, and include the gasket that seals it to the tank (a large o-ring). That's about all there is to it, I will say it's a very tight fit to get your hands past it to unclip/reconnect the lines, and it barely slides out of the hole in the body, they are almost exactly the same size. Have patience.

 

Thanks a ton for posting this. I will read through it in detail and take a stab at it. Regarding the comment in the procedure about relieving pressure in the fuel line/s, is there a shraeder valve around there to do it or would you recommend doing it from under the hood? Or would that not be a concern for me since its not holding pressure anyways?

I have the part ordered from FCP Euro. As a follow up to my earlier post regarding the part options, I did call them and they cross checked with the VIN of my car. Apparently I have to order the cheaper one (the Eurospare one) and not the Delphi one. I will post back once I receive the parts and attempt the replacement. Hopefully I can do this myself.

 

There is no place to bleed it off, if the pump is still working you can start the engine and remove the fuse/unplug the pump, allow it to run until it dies, there will be very little pressure left. I just cover the fitting with a rag and pop it off, just be careful to avoid fuel getting into the interior as the smell does not go away.