When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
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?
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.
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.
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
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.
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 11:49 AM.
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.
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.
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.
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.
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.
06-20-2018, 01:21 AM
