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My research shows that Standard FPS 7 is a direct replacement - still pricey at $130 but available at my local O'Reillys. (Lifetime warranty). Since I have a functioning '04 XJR that has the identical part numbers for the fuel pressure regulator I will swap them and see if I am on the right track. Hopefully I can do it today after work.
That was what I was going to suggest, but I wasn't sure if you wanted to disturb your running vehicle.
When I went down this rabbit hole is was leaning toward buying this one. I first bought a junkyard one from an s-type and found that that mine was working correctly. I should point out that I used my OBD II reader to see if the transducer was reading the same as my pressure gauge, and it was, making me suspect a problem elsewhere, which I later confirmed.
That was what I was going to suggest, but I wasn't sure if you wanted to disturb your running vehicle.
Yeah, leave things that are running alone. That's my motto... most of the time... but there are valid exceptions.
Originally Posted by Jacuar
When I went down this rabbit hole is was leaning toward buying this one. I first bought a junkyard one from an s-type and found that that mine was working correctly. I should point out that I used my OBD II reader to see if the transducer was reading the same as my pressure gauge, and it was, making me suspect a problem elsewhere, which I later confirmed.
Just curious: what ended up being your problem and what do you use for OBD II reader?
bluetooth OBD II adapter with my Iphone with the Car Scanner app. It works great for standard engine codes, but it does not read chassis codes.
The problem I had was that the car was throwing a P0191 engine code, which means that the fuel rail pressure is not what is expected by the ECM. Since it is a returnless system and does not use a regulator, the ECM requests the required pressure for the conditions to the fuel pump and the fuel rail pressure transducer will confirm that the requested pressure is achieved. If it is not, it will throw the P0191 DTC. The main causes for this could be an obstruction in the fuel line (i.e., a clogged filter), a lazy fuel pump that cannot meet pressure demands, a leak, or a bad FRP transducer. None of these were the case for my problem, so it became likely that I had an internal tank leak. What I found was that the check valve in the fuel pump module had broken at the seams, causing most of my fuel pressure to bleed off into the tank. So essentially, the pump was running at full duty cycle, but the pressure at the fuel rail was only 24 PSI, measured by both the FRP transducer and my mechanical gauge. I replaced the fuel pump module with a used unit sourced from a junked x-type and that instantly resolved the issue. I had previously replaced the fuel pump motor in my original module with a brand new Ford replacement for $10, but that did not solve the problem, which eventually led me to suspect an in-tank pressure leak, which it was.
I have yet to replace the check valve on my rebuilt original pump module, but the problem was visibly obvious so I am confident of the diagnosis. I have been enjoying driving the Jag around too much to venture back into repairing and reinstalling the original module, but I will soon. I have some indecision about the type of check valve I should install...
- Is your car a late '06? ("H" last five VIN) If so, the fuel pumps are indeed different, and generally trouble free (and, if so, you've got an X356...)
- Crank sensor low voltage prob battery cranking voltage is low
- I've replaced my FPR as well; found ford part online for ~ $50, IIRC (Ditto comment above - only use ford or ND electrical parts)
- Nice shop and lift. You prob have OBDII scanner, but suggest jag sw package if you don't already have (I use cheap Foxwell NT510 for jag and BMW. Mostly works fine, and - as noted above - shows live sensor data, which can be helpful)
- Glad to see some talented DIY'ers getting involved with these great old jags. The X356 XJR is a gem...
Hi Laconia I buy and repair a lot of french cars yes sacre bleu but of the 6 I've done in the last couple years while Covid was on that did not start turned out to be the key fob the damn imobiliser!
Not sure if your car has a pair of keys or just one some of the earlier X 350 cars have a glass chip in the remote look it up
I had mine removed and replaced with a modern chip before I dropped it again apparently if you drop the key with the glass chip to many time it shatters go figure
From what you've described sounds like the problems I've had with the Puegeot and Citroens
Very frustrating and can be a bit expensive as you need the dealer level diagnostic to write a new key and switch of the old key you can only have 3 keys on the car at one time learned this the expensive way as well
I couldn't just go to a locksmith and use a key copier
I've now got a Chinese clone OEM diagnostic tool for the frogs and I actually get into the ecu and switch of the imobiliser still keeping central locking and remote functions just delete imobiliser function that way if I sell the car and they lose a key or drop it to many times the remote functions might not work but the car will start
- Is your car a late '06? ("H" last five VIN) If so, the fuel pumps are indeed different, and generally trouble free (and, if so, you've got an X356...)
H04574 - not sure if this is an early or late? My '04 has two pumps and this one has one. Pump has already been eliminated as a potential suspect. I was going to swap the FPR from my 04 to the 06 but for the life of me, I could not get the pump to turn off even after removing fuses #33 and #24 i(to bleed off fuel pressure) so I gave up - it was getting late anyway
Originally Posted by hisport
- Nice shop and lift. You prob have OBDII scanner, but suggest jag sw package if you don't already have (I use cheap Foxwell NT510 for jag and BMW. Mostly works fine, and - as noted above - shows live sensor data, which can be helpful)
Thanks. I have several cheapy generic OBDII scanners but just not happy with any of them. I also have IDS/SDD 131 running on an old XP laptop that's hanging by a thread with an original full fledge Mongoose cable but that is really a dog and pretty unintuitive. Autel Maxisys Elite or Ultra make me drool but it would be way of an overkill for what I do. Most of my cars are carbureted...
Yup, and congrats - you've got an X356 (which you'll discover is very different from x350 models, esp electrically. Engine is VVT, and makes more power than earlier models). I'd be interested in your thoughts after you've road tested your new car vs your older one...
- I got my NT510 scanner 4 yrs ago, after buying my XJR. Prob better options avail today. Sounds like you're on top of it
I did swap the FPR from the '04 to the '06 and I verified that indeed I am getting the right fuel pressure now!! - both via the analog gauge and through the scan tool. However, the no-start condition persists!!! I hooked up a battery charger that is also an engine starter so that I am ensured the right amount of power is available but it still did not help.
I sprayed starting fluid down the intake like I did previously multiple times but the engine did not catch as it did prior. Back to square one and back to what appears to be an ignition issue. This is definitely a challenge and its under my skin which is bad news for me because I won't let go until I have answers....
Yes, exactly! I have one in mind, but I am not sure if it will work properly as it is only a one-way check valve. It will only prevent pressure loss in the line, but not prevent leakage in the system if the line is severed.
The fuel pressure sensor/regulator by Standard FPS 7 is a direct replacement for the Ford unit our XJRs have. Since I transplanted the good unit from the '04 to the '06 and did not want to have a disabled vehicle for days until a unit made it from mail order so I went to O'Reillys and picked one up. It is very expensive and it is made in the USA. This unit does not cross reference as fitting our Jags but it does. As a matter of fact, if you look at the sensor pictures in the bottom right corner those numbers are *identical* on both.
I installed it on my '04 and it fired right up. Pressure reading is identical to what it read before the swap so there you go - in a pinch you can install one of these. If fits many Ford vehicles (including a '04 Ford Focus....) Numbers are identical to the Ford unit removed My '04 - one of two daily drivers. My back up daily is an '87 Mercedes 560 SEL - the Vette in the background is a toy.
- Just for grins, check and clean up the front bulkhead grounding points (in front of the radiator; inboard of the headlamps; fragile aluminum ground studs. My '07 XJR died on the road; towed home; this was the problem)
Any idea of the history on your '06 XJR? Did it expire naturally, or was it a "no start" after someone "fixed" ir?
- Consider that you may have found (and corrected) the original problem; now, sorting out previous repair attempts could be the challenge
- eg; - Any evidence that someone may have botched up valve timing? Installed incorrect ignition/other parts? Left something disconnected? Are VVT sensors in place and connected?
- Does the engine have decent compression across the board?
- When you were able to get a brief start with fluid, did it sound right or ragged?
- Are the coil packs original/correct?
- And, following your inclination, see if you get a sharp, snapping spark on all plugs - both banks - in free air (this is the sort of stupid old school stuff that I would do)
- Anecdotally, IIRC, some folks have found ECM connector corrosion; symptoms no start or intermittent
- Might be worth a look see (also to confirm that ECM is correct pn; might have an X350 (vs X356) junkyard ECM in there as a result of previous fix attempt (parts changers seem to love replacing ECM's when they run out of other ideas)
- You may be able to get ECM module ID data on your scanner and confirm whether it is correct
Thanks for the recommendations. I really thought this would be an easy fix but it is not in the stars this time. I will take a more methodical approach and invest more time to peel this onion through to its core.
Today my calendar is clear (well, its Sunday) and won't come out of the shop until its time for bed. I do not hope to have a solution but rather more information. IDS/SDD is able to connect to the ECM with no issues. There two generic codes that always come back right away even after they've been cleared:
Engine bay looks clean and tidy and the major benefit that I have is a functioning XJR. I will start with ground points, hook up Pick to look at electrical signals on both coils and injectors, compare those to the '04 and go from there.
- Your approach to date is super methodical, IMHO (...and I'm convinced that you'll find the problem, at this rate)
- "Barometric Pr Sensor" ? (I would have guessed that this was incorporated into the MAP sensor, but apparently not)
- Couldn't find reference in the X350 stickies 2004 MY service docs, but did find in S type '06 doc - looks like it may be inside the ECM (details copied below)
- Given your obvious skills and experience, I'm sure you'll clean grounds and check ECM connector before assuming anything bad about your ECM
- Here's the reference:
4.14 Barometric Pressure Sensor
The Barometric pressure sensor (also referred to as the High Altitude Compensation sensor) is located within the ECM.
4.14.1 High /Low Input Failure These are continuous monitors. The voltage from the sensor is compared to a failure threshold defined in the software. If the voltage is below the low threshold, then a timer starts to increment. Once this timer exceeds another threshold, then a failure flag is set and a DTC is stored. If the voltage is over the high threshold defined in the software, then a timer starts to increment. Once this timer exceeds a threshold, then a failure flag is set and a DTC is stored. 4.14.2 Range / Performance Failure The signal from the sensor is compared to the signal from the Manifold Absolute Pressure sensor (MAP) at ignition on only. During this time the pressure within the inlet manifold should be at atmospheric, and therefore should match the value from the barometric pressure sensor. The following conditions must be met first before the monitor can execute; Engine speed = 0 Vehicle speed = 0 Monitor is not inhibited Ignition is on Engine is not cranking Battery voltage exceeds minimum threshold Coolant temp above minimum threshold Atmospheric pressure within limits Inlet manifold pressure value has settled If the absolute value of the difference between the signal from the barometric pressure sensor and the MAP sensor differ by more than a defined amount, then a timer is executed. If the timer exceeds a calibrated amount, a temperature failure is judged. Providing there is no failure of the MAP sensor, a DTC is then stored. Jaguar Cars Revision Date: May 2005 Page 76 of 119 Barometric Pressure Sensor Component/ System Fault Codes Monitoring Strategy Description Malfunction Criteria Threshold value Secondary Parameter Enable Conditions Time Required MIL Barometric sensor high input P2229 Out of range check Sensor voltage >= 4.79 V 16 2 drive cycles Barometric sensor low input P2228 Out of range check Sensor voltage 10 kPa Engine Speed Engine coolant Temperature Intake air temperature Vehicle speed Battery voltage (B+) Time after ignition On Delta MAP = 0 rpm >= -30 °C >= -30 °C = 0 mph >= 10.5 V 64 < time < 1000 msec <= 0023 kPa per 32 msec 0.192 sec 2 drive cycles Disabled DTCs P0069 P0101 P0106 P010B P0133 P0140 P0153 P0160 P0401 P0420 P0430 P0441 If the above table does not include details of the following enabling conditions: - IAT, ECT, vehicle speed range, and time after engine start-up then the state of these parameters has no influence upon the execution of the monitor.
For those first timers that are wondering where those ground studs are "behind the headlights" here they are. The radiator closing panel needs to be removed. Fairly easy - remove the reusable clips carefully.
Mine were in decent shape. I removed the nuts carefully and used a dremel tool to clean the stud threads, the nut and the wire connector to a shine. Of course that did not help my problem.
Next will be ECU connector inspection.
The cowl vent screen was removed using the instructions found in the Body and Paint Manual section 76.10.01.The windshield wiper arms may be stuck really well onto their respective studs - you need to use a small puller just like the one used to remove battery terminals. There were 2 more items besides the cowl vent screen that covered the ECU connector but it was straight forward removal. One requires removal of 4 nuts (in my case one was missing and the other three were hand tightened - is this a clue? The other piece is held by one bolt (also hand tightened).
The connector and pins were spiffy clean. I do not see any problems - let me know if you think otherwise....
Probably time to go under the glove compartment and pull this thing out and see what kinds of marking it has....
Once I removed the cover from under the glove box compartment, getting to the ECU was no issue whatsoever. You remove the two nuts from the bulkhead and remove the ECU from under the glove compartment as shown below. All bolts were hand tightened. Did not have to use a socket or wrench. So, that tells me that *maybe* the ECU was replaced but not programmed correctly? I do have IDS/SDD but have not done any ECU programming ever. I would not mind giving this a try if someone has a write up on how to do this. The board looks nice and clean and it does not appear to have been subjected to any abject weather conditions (like water ingress, for example).
Look at the pictures below and see if the numbers should be what is shown below for an '06 XJR.
I buttoned up the ECU and re-installed in the car. I decided to go back to my troubleshooting flow. I have fuel pressure and I have ignition as witnessed with the engine catching when starter fluid was sprayed in the intake. I hooked up the Picoscope in one of the injectors and with ignition on I did not get the reference 12V I was expecting. I had printed out the schematics for the MY2006 and started studying them. Going back from the injectors, it took me back to the front power distribution box and to fuse #13.(relevant figures are 1.8 and 3.6). Testing for power across the fuse with the ignition on I realized that only one side had power. I was expecting for internal relay R11 to be bust but no! The damn fuse was burned. I quickly swapped the fuse and attempted to start the car and it caught. However, the engine was shaking and the noises coming from the engine bay were absolutely horrendous. It idles horribly but did not let it run more than 2 - 3 seconds. I repeated a few times with the same results. When I lifted the car up to see where, what appeared to be exhaust noise was coming from, I realized that while the driver's side catalytic converter was hot, the passenger side was stone cold. So, at least 4 cylinders are not firing at all. I double checked the injector harnesses and verified that I was getting a signal to the injectors on the bad side. Since car sat for a year (may be more) I would not be surprised that injectors clogged up.
Next step:
- Compression test across all cylinders
- If that succeeds, I will remove all injectors and have them tested/cleaned/replaced and go from there.
If compression fails miserably, then the car will be up for sale. It would make for an absolute perfect parts donor. Immaculate leather interior, navigation system, Sepang wheels etc. - the paint on the car is recent and it looks awesome. I would rather sell the whole thing and may be break even.
Good work! Well, I think the good news is that all four cylinders on the same bank losing compression isn't the most parsimonious possibility, so hopefully your compression tests will yield some positive results there.
Also of possible relevance, one wonders what caused the injector fuse to melt... You could try swapping the injectors across banks to see if the problem switches sides, but I suspect it is more of an electrical issue since it is an entire bank. Perhaps, if the wiring is long enough, you could first try to swap the injector wiring across banks and see if the problem switches sides. --edit Sorry, I just saw that you had already verified signal to all of the injectors. Sorry if you have already mentioned this, but what have you found out about spark in all the plugs?
I am optimistic that you will figure out this problem and it is great that your ECU is functional.
Last edited by Jacuar; 11-15-2021 at 04:22 PM.
Reason: Updated
Compression test confirmed that the engine is indeed toast.
#1: 135psi
#2: 100psi
#3: 130psi
#4: 105psi
#5: 135psi
#6: 0psi
#7: 40psi
#8: 0psi
Piston tops looked really scored and beat up on #6 and #8 (adjacent cylinders on the passenger side) as if something was dropped and danced around.
I could buy an XJR engine and pop it in (there is one on ebay for $1500 from an '07 - video proof is also available for its health) but I have way too many projects to entertain this.
If anyone is interested in purchasing the complete car as is (Sepang wheels, navigation etc - complete car) PM me.
11-11-2021, 01:26 PM
