On my usual monthy 150 mile round trip from home over the mountain range pass to buy lotto, my kitty started stuttering on load. Then it threw a P0171 (lean) @ about 40 miles. OBD said everything normal, fuel trims, pressure, etc. Cleared the code ran good (1/2 trip mileage to 75). Started back @ about 20 miles, on pass load began stuttering again. Pulled over, got P0171 again. Cleared, got another 40 miles & another p0171. Cleared, stopped to buy some MAF cleaner, hoping to nurse it home and try that. Got 5 miles away (10 miles from home) & it coughed up a hairball, went into limp mode and threw a P0191 & P2635 & full throttle would ALMOST go 2 m.p.h.

Called the wrecker to tow to a fraking expensive Foreign car repair place here that is dedicated to automobile service, sales, and upgrades for Audi, Bentley, BMW, Porsche, Lamborghini, and Volkswagen owners.

Here's an odd bit. As I have always posted here, I have NEVER (repeat never) been able to hear my fuel pump run when turning on my ignition. I always turn the key, wait for the dash lights to extinguish and then start the car. Sitting on the side of the road before figuring I'd better tow it, the fuel pressure read 23-26 p.s.i. Turned it off to wait for the tow and could hear (for the first time ever), the fuel pump running with ignition in the on position. AND it continued to run as long as the key was on. So I think (hope) that will point to the problem being the fuel filter.

Here's my reasoning. If relay was bad, no fuel pump working (no sound), if relay good, pump bad, no pump sound. Pump running continuously = plugged filter, no pressure at rail, which is where I make an assumption the fuel pressure is read on an OBD(?).

Does this sound like a reasonable thought process?

 

 

Not a fuel filter. Specify what the codes mean.

 

 

Dell, I would not rule out the fuel pump quite yet. Yes, replace the fuel filter to see if things are going to be cheap for you. But, if the fuel pump has internal binding (making it cause more noise), that would cause the pump to turn slower, generating less pressure. Also, with age, things are getting worn. So, the gaps inside the pump can be greater, allowing more internal leakage and therefore your pump has less volumetric output, therefore, your pump will also only be able to reach a certain pressure.

Based on what you are describing, I am wishing you luck in that it is just a fuel filter. But, I am willing to place money that it is the fuel pump that has gone.

 

Boo......

 

fuel pressure should be around 56psi

 

UPDATE:
Decided to replace fuel filter while sitting in garage's parking facility. The residual gas in the filter looked like it was very rusty. About the color of 1/2 cola & 1/2 water when poured out after removing. I thought, AH HA, that's it. Turned the key on and (again NEW TO ME on my car), heard the fuel pump cycle, but then shut off this time (still new sound to me) I had plugged in my OBD prior to this procedure. 0 p.s.i., as expected before key roll. It went up to 6 p.s.i. I kept rolling the ignition from off to on watching the pressure each time. After about 9-10 cycles, pressure was around 52 p.s.i. Rolled the key to start, popped right on. DAMN! I'm saved!

Thinking of all the research I've done. Guidance is that failing fuel pump will usually occur on longer distance trips (particularly using cruise control) & will manifest when a load occurs (think climbing a steep and/or long mountain pass). So off I go, warmed the car up, took it to a steep incline 4 lane highway from the mouth of our convenient canyon passes here in Utah. Began pulling the hill that is about a 7-8° grade @ 40 m.p.h. Letting the car begin to strain to maintain the speed. VERY SLOWLY pressed the gas to increase acceleration and not immediately kick a downshift and BANG! Clicked, stuttered, hesitated and threw the P 0171 lean code with m.i.l.

SUCK!! Proved it's a failing fuel pump! Now to find one I can afford and see if I can find a trustworthy foreign car mechanic that will REASONABLY install it. While I'm doing it, I'm going to replace the secondary sending unit because as posted in other threads, my "changover" from main to secondary has never worked. I truly believe this is superfluous as I believe it has always been the electronic failure on the main (LHD, passenger side) pump when float arm tells it to siphon gas from the (LHD) driver's side, it does not. But crap, they'll be in there anyway, why not?

Pics of cut open fuel filter, it was actually pretty clean attached.


Fuel filter just removed


Fuel filter, cartridge removed, inside of canister clean as a whistle, no sediment


Close up of filter cartridge
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mine looked the same inside

 

Dell: Sorry about your fuel woes. I hate to agree the likely culprit is a failing fuel pump, particularly since it persists after you replaced the fuel filter. It's a long shot, but you could try replacing the fuel pump control module. They don't often fail because it's located far from engine heat, under the rear seat on the US driver side. But to rule out this slim possibility at minor cost and effort, $40 buys a used module on eBay or from dr dome, and installation is a simple DIY job compared to fuel pump replacement.

Regarding your fuel pump failing to siphon gasoline from the US driver side to the US passenger side, the mechanism is simple Bernoulli's suction, powered by excess flow from the fuel pump on the US passenger side. So a failing fuel pump could also explain why fuel is not being siphoned from the US driver side. Astromorg shared a helpful picture of the flow inside the fuel tank in this post. The siphoning occurs whenever the fuel pump is running, without regard to the fuel level sensor on the US driver side : https://www.jaguarforums.com/forum/x...7/#post1101975

 

before changing the fuel pump ( big job on 2.5 and 3.0) try changing the fuel pump control unit, fitted under rear seat hidden away. it drives the pump from a PWM signal from the ECU. I had one start to playup.

changing fuel pump means dropping the fuel tank or cutting holes in the metal under rear seat.

 

 

So I'm running down 2 sources for a used pump. Have spoken to enough knowledgeable people to feel as secure as I can be (type A & pretty OCD) that replacement of the (LHD) passenger side pump will cure my problems. My thought process of main pump not pulling fuel by "telling" itself to suck from the left side tube proves to be erroneous. As described, they say both tanks are supposed to be about equally full in level for weight distribution (handling). Makes sense. And that the low fuel light on the dash doesn't come (although does and cycles off on initial key roll) because it's controlled by the right side sensor. Again this makes sense as the deeper "reserve" fuel well is on the right side. 3 folks have assured me that the left side controls (shows) ONLY fuel level and that does function on fill up (full) diminishing on use.

The rub is labor. Dealer is 6 hours at $130.00/hour. Have found 1 independent that quoted $808.00 & 1 @ $105.00/hr plus $20.00 each for gaskets at 6 hours. Finding a shop (surprised dealer does it) that will install a used pump is also a huge hurdle.

So.....I've decided to try the "cut plate from under back seat" method. I purchased a neat item today called an air driver metal nibbler. Watching demonstrations it's pretty darn slick and WAY fast cutting metal. Also, because of how the nibbler tip works there will be next to zero chance of cutting, clipping or damaging a hidden wire, tube or such. Clean lines and edges which will hopefully facilitate reinstallation of the removed access plate cut out. Still mulling that one = tack weld corners and aluminium bond the seams for easy access if ever needed? Weld the whole thing, messy, no access...........

Anyway, when I buy receive pump (yeah just pump) and tackle this project I will attempt to well document the steps w/pics, time, ease/difficulty, etc.

As always, thanks members for your ever valuable input and guidance.

 

 

I have a complete tank with the pump assembly if you want it, but expect the postage costs to rule it out . I've changed the tank and pump assembly twice so know whats involved. main thing is to drain the tank with a suction system before working on the car and have a fan and fire extinguisher on hand . the fan to vent the area to prevent any fumes collecting and the extinguisher in case it goes wrong.

I did mine by dropping the tank as cutting the metal under the rear seat reduces the structural strength of the chassis and its double skinned in some areas and cutting is a problem. .

 

Dell: Welsh Enterprises sells a new pump without the canister, part # C2S41300 for $86 +$9 S&H (vs. $300-400 with canister). I have one in my X-Type without a single hiccup for the past 4 years and ~30K miles. Here's the link: https://www.welshent.com/Search.aspx?k=C2S41300

Instead of dropping the tank, I cut an access hole thru the sheet metal under the rear seat. It's not difficult, and is small enough not to be a structural risk, imho. Plus I now have easy access if ever needed again. With the tank nearly empty, undo the 2 metal straps that secure the tank, then lower it ~2-3 inches on the right / US passenger side, supported by jack stands while you work. This gives you an extra ~2-3 inches of clearance to cut the access hole without risk to the tank, hoses or wires. As an extra precaution, I covered the tank with a wet terrycloth towel and a piece of scrap sheet metal over the towel. The access hole is cut on 3 sides and hinged / bent back on the 4th side (towards the trunk) the during the repair, then bent back into position and secured afterwards.

This thread has pictures of a similar approach, except they cut full circle: https://www.jaguarforums.com/forum/x...cement-130721/

 

Holy moley, dw, that link is WAY more comprehensive than I could ever do, thanks. The procedure on video I felt I could do, so with that link here, I think there is very little I could add in explanation or pictures. I have come up with a thought and process to fix the cut out. If it pans out, I will add that when I tackle this job.

I do now though have a creeping concern having watched the guy in U.K. who I've posted videos of his work because is is so thorough and camera work is always great. He replaced only the main pump side and after installation, before buttoning up the cut out, his gas gauge had stopped working. He pulled the replacement, took the electronics (as he described, the "rheostat", that felt soft on replacement) from the failed pump and put on the replacement. Reinstalled and gauge worked as before.

Here's the concern, I was told the secondary sending unit controlled the guage! So, wtf? I'd hate to change the main and still have the problem of not using all the fuel and no fuel light warning. Gotta love working on cars, smh.

 

Dell: Our X-Types have a single fuel pump on the right / US passenger side of the tank. When the engine is running, this single pump constantly pushes fuel thru an internal hose to the left / US driver side, where more fuel is literally sucked from the left side and flows thru a 2nd hose back to the right side of the tank. How? Bernoulli's principle! Back in the day when we rebuilt carburetors, Bernoulli's principle is how fuel was sucked uphill from the float bowl into the air stream rushing thru the carburetor venturi. The same principle works in our X-Type fuel tank - a rather ingenious way one pump sucks fuel from both sides of the saddle tank.

https://en.wikipedia.org/wiki/Carbur...Carburetor.svg

The two level sensors measure both sides of the saddle tank to display the combined result on the dashboard gauge. If one or both sensors fail, the dashboard gauge will be wrong. But this won't interfere with the single fuel pump as it continues sucking fuel from the left side to the right side of the tank.

When I replaced the fuel pump in my X-Type, I cut one hole on the right / US passenger side to access and replace the fuel pump. There was no need to cut a 2nd hole on the left / US driver side.

 

Thanks, as stated above (looking), I have now sourced just the main pump and plan on doing just that side. It just raised my concern (yeah, OCD is a bitch) when the U.K. guy's gauge failed on that side. Not having my kitty use most of the fuel is bothersome at most. It was just a little bit of a learning curve to know the low fuel light never illuminated and it would run out of fuel with no warning at around 80-95 miles of range still showing. When it did this 3 times, filling with just a 5 gallon jug popped the start immediately, no extra cranking at all.

 

Dell: When you open the fuel tank on the right / fuel pump side, you may discover a problem with the 2 internal hoses that convey fuel to and from the left side of the tank. The hose that sends fuel to left side is connected to the fuel pump output. Perhaps that hose has somehow split or become disconnected from the pump. The hose that returns fuel from the left side simply inserts loosely into a hole in the top of the fuel pump canister. Perhaps that hose has slipped out of position and is now recoiled back to the left side of the tank. Hopefully you'll be able to see and resolve this by accessing only the right side of the tank when you replace the pump.

My X-Type's problem was limited to and solved by replacing the fuel pump only, so I did not access the left side of the fuel tank and have no learnings to share on that side.