I am baffled about my XF stalling problem and I need some expert advice. I will try to give as much detail as possible.

In January 2015 I bought my 2012 Jaguar XF. Several months later in June/July, I was pulling out of a restaurant parking lot, within 10 seconds after driving off the car cuts off, but started right back up as if there was never an issue. A few weeks later it does the same thing again, but this time it does not start back up. I end up having it towed to the nearest dealership. They told me it was a failed fuel pump. I have the fuel pump replaced and car is running like new again. A month later I'm in a different city and it does the same thing again, but eventually starts back up. I take it to the dealership there. They told me they could find nothing wrong with my car and that it was operating just fine. Then just recently, barely over a week ago, I was coming back from out of town and the car stalls out on me again on the interstate. After several rinse & repeats I managed to get to a Quality Inn hotel. Tried again early the next morning and it operated as if there was never an error. However since then, it has consistently cut off once a day for the past several days. The dealership that installed the new fuel pump for me told me to bring it in so they could look at it, but also stated that if its not showing a problem while they have it they would be unable to isolate the issue. Servicemen also mentioned they could try to recreate the conditions that problem occurred in, but with it being so random I don't believe there is an established pattern.

Warning Lights:
-No warning lights are displayed before it happens, but afterwards the check engine light is illuminated.

Conditions:
-I purchased the vehicle in January and did not have any problems during the cold weather.
-It has occurred at both day & night.
-There has never been a set time of when it would happen. On one hand it has happened within less than a minute after starting it up and driving off, then on another it has happened 4 hours later after being on the road when driving during normal daylight hours.
-The amount of fuel in the tank has varied. It has happened with as much as just shy of a full tank and as low as just above ¼.

Other things I’ve noticed:
-Sometimes(completely random) while the car is parked(whether just starting it up or after just driving) its idle is slight irregular. The RPM hand displays a slight flicker while feeling an unusual sway/vibration from the car.
-When driving the car, right before it happens the car will give a quick indication by a significant drop in RPMs & MPH. At that point you have anywhere from 3-5 seconds to maneuver the car into a safe location.
-Sometimes when trying to hear or better understand the problem, I would rev up the engine while parked and when doing so I noticed that each time when the RPM hand would get to 4 RPMs I would feel a jolt in the rear part of the car, but it would only do it when it got to 4 RPMs.
-However, I’ve also noticed that after letting the car sit for several hours it tends to operate without error. But again, this all at random of when this would take place. The only thing that is seemingly to appear consistent is the frequency of when it happens which seems to be growing by the day.

Also, I do not know if this would make a difference or not, but a month after I had the car my wife accidentally put Regular gas in it and of course the system notification stayed lit, but I did not want to mix the two so I ran all of that out before I filled back up with Premium.

Please Help.

-Mike H.

 

I had that problem with a 1998 XJ8L. I pinned it down to stalling only when I took my foot off the gas while cruising. So it tended to do it while I was on the highway. Terrifying situation because you can't stay on the gas all the time, and if it stalled, you had to pull over, come to a complete stop before you could start it up again. Dangerous depending on the freeway situation.

Many trips to the dealer in vain, and they finally seem to solve it with a new throttle body.

But I was pissed by then, and sold the car within a couple of months. It didn't do it again while I had it, so I guess that fixed it. Never heard anything from the proud new owner after he drove away with it.

 

Yea unfortunately minds do it when foot is on and off. Very frustrating for me and hard to narrow it down to a possible problem.

 

If the check engine light is on there should be some fault codes that your dealer should be able to pull if you make a note of the mileage/date. If you don't want to trouble your dealer, find a Jag indie who has the right code readers. Does the check engine light eventually go away by itself ?

 

The check engine light is only illuminated when the engine goes dead. Then once I turn the car/power completely off the check engine does not come back on. I guess its like turning the key in the on position but not quite starting the car. Thats only the time the check engine light is illuminated.

 

This same situation was happening to a friend of mine. Issue was his fuel pump. Do you often run the tank close to empty that could have caused them to fail? Could the new one have been defective or improperly installed?

 

I never let the tank get that drastically low. As far as as the new pump being defective or improperly installed, that could be a possibility. If so, I wish the other dealership would have discovered such when they took a look at it, but they reported no problem discovered. I made them aware of all the details.

 

Sometimes they need prompting that the symptoms are exactly the same as before.

 

>>>Do you often run the tank close to empty that could have caused them to fail?

The low tank causing fuel pumps to fail is a wives' tale.

It's based on saying that the fuel pump uses to the fuel for cooling the pump and that's why you need to keep the tank full.

The fuel pumps are mounted pretty high in some tanks, so you would have to keep the tank over 3/4 full all the time (not going to happen) to keep them all submerged.

But the bottom line is that by design the fuel flows through the center of the pump regardless of whether it is submerged, and it's that flow through the center that keeps it cool.

The flow is continuous regardless of the load on the engine, so it's always getting the cooling it needs.

And any debris in the tank will be at the bottom whether the tank is full or empty. The screen on the fuel pump pickup prevents that stuff from being picked up.

It's time to let that wives' tale die. We already have too many as it related to cars.

 

Hi Mike, I had roughly the same problem with mine. I took it to 2 different mechanics said it was running lean. To which I tried to find a leak in the intakes. Nothing so I was going to take it in time the dealer and since it was up in the air I had the mechanic do anot oil change and filters. After the air filters were changed its been great ever since. Hope it's that easy for you too.

 

Rather than argue the point that running low fuel IS a cause of electric fuel pump failure →→→ https://www.google.com/webhp?sourcei...mp%20to%20fail
With that out of the way, your issues are classic bad fuel pump or fuel system symptoms. Your car is a V8 so it has 3 fuel pumps, 2 on the engine for high pressure and one in the tank for low pressure, they all have pressure sensors that report to fuel pressure to your OBD 2 port, making it possible for you to see if there is a fuel pressure drop in real time with a OBD 2 dongle and a real time diagnostic app like Torque.

 

Buddy, do the googles to find out that's a wive's tale that continues to be perpetuated by idiots.

And don't pretend like you know what's wrong with his car. It could literally be anything for all you know, so don't try to narrow it down.

 

I knew it, as usual the village clown, is arguing to stay in the WRONG , and since only an "IDIOT" argues to stay in the wrong and you got that DOWN!
And as far as me making suggestions as to a solution to this problem, IT'S NOT YOUR THREAD. SO STAY IN YOUR LANE!

 

 

LOL...

 

Mike H did you ever find out what was wrong? Mine is doing the same now. Already replaced air filters and did fuel injection flush.

My mechanic is saying it currently has the following problems:

1. Measuring 7 volts instead of 12
2. Pressure on sensor wants 1300 getting 1800
3. Sensor on the fuel pressure regulator is malfunctioning.

Any help you can give would be appreciated. Mine is a '12 XF Portfolio.

 

i have the 12 XF portfolio. a lot of these cars had a gas sloshing issue that led to a jaguar fix where they installed some sort of baffle in the gas tank as i understand it. i did not do it, as the slosh didn't REALLY bother me that much. since OP bought used, i'd wonder whether the original owner had that mod done and whether something has now broken in the gas tank itself. not a mechanic, just thinking out loud here...

 

Thank you, it was towed to the dealer today. I'll post here once I hear from them. They did say if its a fuel sensor issue the warranty will cover it.

 

So have you any luck with determining the verdict? I am having the same issue with "lean conditions" per my visit to mechanic last week - had an intake tube replaced and now experiencing the stalling issue (3 times today)

thanks!

 

Yep it was the fuel harness. Fully covered by extended warranty.