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XK / XKR ( X150 ) 2006 - 2014

MAF Sensors

  #41  
Old 06-20-2018, 02:21 AM
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Originally Posted by Ranchero50 View Post
Quit wasting money on parts until you have some idea what's wrong. Until you actually know what pressure is at the rail everything is still suspect. You could have corrupted data from the sensor or PWM problems from the ECU to the driver. From experiences garnered from the forum over the past year all of this can still fall back against the battery. The X150 is a fickle beast when it comes to electronics and controls. At least you aren't paying a shop to misdiagnose it yet.

Did you read the section of the service manual on the fuel system?
I did read the Service manual section. When I reread it today it made me wonder if there would be specific FPDM codes thrown by the system if that was the fault.

I've never found a surplus of Jaguar parts to be a problem when daily driving one. I acquired a fuel pressure sensor and will be checking that in a sec. I did however delve a little deeper into the OBDII fuel trims and I found something interesting. My long term fuel trims on Bank 2 were lower than those of Bank 1. B1 hovered around 4.7 to 5.5, Bank 2 was about 1.6-2.3.

When LTFB B2 was at 1.6 the STFT B2 was at 2.3, when the LTFT B2 was at 2.3 the STFB was at .8

Meanwhile when the LTFB B1 was at 5.5, the STFB was at 0.0

Shouldn't both banks be closer than that or am I gravely misunderstanding?
 
  #42  
Old 06-20-2018, 07:26 AM
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I wouldn't overly sweat the discrepancy yet. Possibly you have a wonky o2 or two.
 
  #43  
Old 06-20-2018, 12:12 PM
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Didn't get to check Fuel pressure last night, First on the agenda after work today. On the way to work this morning fuel trims on both sides reached as high as 13 with some frequency. The battery read 12.30 after a 24 hour rest last night. The car has half a tank, but the DTE on the cluster is reading 50 miles, which is impossible. I'm still averaging 20 in the city.
 
  #44  
Old 06-20-2018, 12:28 PM
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Do you have a Ctek or other battery maintainer? Plug it in overnight and check again.
Might also be worth getting one of the $10 cigar light plug in voltmeters.
 
  #45  
Old 06-20-2018, 03:54 PM
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Originally Posted by Ranchero50 View Post
Do you have a Ctek or other battery maintainer? Plug it in overnight and check again.
Might also be worth getting one of the $10 cigar light plug in voltmeters.
I do. Already gave that a shot. No change in symptoms. Actually, a few days after I replaced the filter and cleaned the MAF when it was running flawlessly for a few days I hooked it up to my maintainer and the next day the problem was back
 
  #46  
Old 06-21-2018, 12:26 PM
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Anyone know where the Fuel Rail Schrader valve is, if there is one? I know the XK8 had one. couldn't figure out where to hook my fuel pressure gauge in and I'm not thrilled about opening up the system. Yesterday the car threw up a warning about a failed brake light, which was working fine, and my stereo did a weird restart thing, so I went back to Batteries Plus Bulbs explained what was going on and they swapped my battery out for a new one for free. Completely fixed my issue for about 15 minutes of driving, then it came right back. If pulling the battery can fix it like that I can't imagine it not being a sensor/PWR issue. I went over as much wiring as I could get to last night and it all looked fine.
 
  #47  
Old 06-21-2018, 12:40 PM
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Yeah, you're into the clean and lube the battery terminals and fuse blocks. Add in the plug in relay terminals too. Cars got a little Lucas running around and needs exorcised. God save ya...

I get the brake light out thingy too but it's always lighting when I can check. PITA.

I assume you could remove the temp sensor from the back of the rail and thread your tester into that. Manual shows how to relieve the pressure @ 2363 but doesn't show exactly where to hook it up.
 

Last edited by Ranchero50; 06-21-2018 at 12:49 PM.
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  #48  
Old 06-21-2018, 12:59 PM
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Originally Posted by Ranchero50 View Post
Yeah, you're into the clean and lube the battery terminals and fuse blocks. Add in the plug in relay terminals too. Cars got a little Lucas running around and needs exorcised. God save ya...

I get the brake light out thingy too but it's always lighting when I can check. PITA.

I assume you could remove the temp sensor from the back of the rail and thread your tester into that. Manual shows how to relieve the pressure @ 2363 but doesn't show exactly where to hook it up.
Daily drove my XJS for three years, I'm no stranger to that game. I cleaned all the grounds to the EMU relays yesterday, no corrosion there and the conditions didn't improve.
 

Last edited by Dymaxxion; 06-21-2018 at 04:31 PM.
  #49  
Old 06-21-2018, 04:31 PM
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I should clarify that the radio electrical issue went away immediately, I was referring to the fuel issue when I said it came back in about 15 minutes.
 
  #50  
Old 06-22-2018, 12:48 PM
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Originally Posted by Dymaxxion View Post
Anyone know where the Fuel Rail Schrader valve is, if there is one?
Actually I don't think that a valve is available. Instead you would have to disconnect the fuel line at the spring coupling, using a plastic tool which disengages the coupling. Alternatively you could remove the sensor on the passenger side (right side) fuel rail, near the firewall. However I think the latter would be more difficult.

Here is an example of the plastic tool, you need the green tool for a 1/2" fuel line.
https://www.amazon.com/OTC-7337-Fuel-Line-Disconnect/dp/B0002SRCYW/ref=sr_1_39?ie=UTF8&qid=1529687487&sr=8-39&keywords=fuel+line+disconnect+tool https://www.amazon.com/OTC-7337-Fuel-Line-Disconnect/dp/B0002SRCYW/ref=sr_1_39?ie=UTF8&qid=1529687487&sr=8-39&keywords=fuel+line+disconnect+tool
 

Last edited by Patrick Wong; 06-22-2018 at 01:14 PM.
  #51  
Old 06-22-2018, 01:45 PM
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That's the irony because there is a procedure in the S/M for using a tool to relieve the pressure before taking the lines off.
 
  #52  
Old 06-22-2018, 02:09 PM
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Why they'd remove the handy Schrader valve from the XK8 is beyond me. A couple developments: My FPRM has arrived, but I can't find the damn thing in the trunk anywhere. Anyone know where it's located? I know it's on the left side of the trunk, but try as I might I can't find it. I've also heard that you can read the pulses from the ECM using a voltmeter hooked up to the white wire on the FPRM's pigtail connector. Yesterday a "Check Fuel Filler Lid" warning came up on my dash. I removed it and retightened it it might have been loose, I can't really recall, but it went away and then came back today. The message is still there. I can't help but think it's related to this issue. Anyone know what triggers that warning? I know on the XJS there is a common fault where the tank stops being able to vent itself and creates a vacuum. Many owners drill small holes in their gas cap (Thankfully I haven't had this issue on mine), but this seems like the opposite of that problem. I'm kinda hoping this leads me to the culprit.

If the battery being disconnected resolves things for a short period I think it's safe to rule out plumbing and wiring (Wiring appears fine under inspection as well). I did some research and it appears that there would be codes specific to the Pump Driver, So I'm kinda thinking that might not be the problem, but "I'm still gonna swap it out because I already have it and I'm grasping at straws here.

ECU
Pump Driver
Pump
Fuel Temp Sensor
✓Plumbing
✓Fuel Pressure Sensor
✓Wiring between anything
 

Last edited by Dymaxxion; 06-22-2018 at 05:45 PM.
  #53  
Old 06-22-2018, 05:08 PM
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Ok, I got lost in the alphabet soup... FPRM?
 
  #54  
Old 06-22-2018, 05:41 PM
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Originally Posted by kj07xk View Post
Ok, I got lost in the alphabet soup... FPRM?
Fuel Pump Control Module. Sorry, typo.
 
  #55  
Old 06-22-2018, 06:57 PM
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Originally Posted by Dymaxxion View Post
Fuel Pump Control Module. Sorry, typo.

The FPDM (Fuel Pump Driver Module) is located on the RH end of the charcoal cannister and is attached by 2 scrivet fasteners.
 

Last edited by Sean W; 06-22-2018 at 06:59 PM.
  #56  
Old 06-23-2018, 06:31 PM
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Originally Posted by Dymaxxion View Post
Fuel Pump Control Module. Sorry, typo.
See page 2380 of workshop manual for picture of fuel system component locations. Manual can be found under the stickies "how-to" quick links post #3 https://www.jaguarforums.com/forum/x...k-links-20091/
 
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  #57  
Old 06-24-2018, 06:44 PM
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Could a vacuum leak at the tank be causing this issue? Code P0193 doesn't seem to have that as one of the possible causes
 
  #58  
Old 06-24-2018, 07:39 PM
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Just thinking left field here, have you checked the charge rate from the alternator?
 
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  #59  
Old 06-24-2018, 08:58 PM
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Originally Posted by Dymaxxion View Post
Could a vacuum leak at the tank be causing this issue? Code P0193 doesn't seem to have that as one of the possible causes
Which issue?

Per the fuel pressure out of tolerance, no.
 
  #60  
Old 06-25-2018, 03:40 AM
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Ran an OBDII test on the alternator. It checked out okay. The battery reads normal with the engine running.

Drat. Well, I guess when it rains it pours. It's currently throwing P0442 as well. Digging into it again with full force tomorrow after work. Found an interesting tidbit when I searched that code. Apparently the ECU tests the EVAP system for Fuel Pressure Sensor Faults. It's killing me that I haven't been able to put more work into this over the weekend, but I'm still dealing with the aftermath of my move.
 

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