So my girlfriend has 2 97 XJ6's one is the Vanden Plas addition. She got me into these cars. They are pretty great, but can be a pain to work on.
The other day my girlfriend was leaving work and she started her car and backed up and went to put it in drive and noticed it had shut off. So she tried to restart it and thought something with the battery happened so she asked a co worker to jump start her can (the battery wasn't the issue) and she got the car started and proceeded home and when she got to the stop light she said she kept for foot on the gas a little to keep the car on ( not knowing if that would help) and when she got home as she turned in her driveway the car just off mid turn because she said the steering got really rough to turn.
I took it for a drive and couldn't get it to do what she said it did. So I decided to floor it and then it started sputtering and sounding like it was miss firing. The check engine light would come on and off but wouldn't stay on at all. (as seen in the video attached)
My first thought was the fuel pump is going out so I got a new one and put it in, but it still does the issue so that's great.
I have looked around and found a few people with the same type issues but not really and updates as to the fix for it. My uncle who is 25 year ASE certified mechanic and I are leaning towards something fuel and fuel pressure related.
We hooked up his code reader but it only goes down to a 2000 jaguar xj6 and comes up with codes for climate control stuff. Northing really related to the engine I don't think. I took a reading from the 2 code readers my uncle has, both readers gave different codes.
First reader. B1853 U1263 B1658 B1861 B1849
Second reader. P1188 P1186 P1185 P0116

I wanted to post something on here for maybe some more insight from people who have some Jags.
Hopefully someone can help out.
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The fuel pressure regulator will bring down the fuel pressure to 43 psi at idle

If the FPR is bypassing too much the fuel pressure will be lower

At idle if you can duplicate your issue in this regain you can pinch the return line from the FPR back to the tank

In this case you would be manually controlling the fuel pressure . it does make a bypassing sound in normal operation .

To ensure the fuel pump is getting proper power ( current ) you can remove the # 1 fuel pump relay and jumper the fwd most and aft most sockets

Best to use a blade type jumper wire the auto parts store can help you make up

Check the connector on the pump itself for burnt sockets which happens

The crankshaft position sensor is reponsible for keeping the fuel pump running as you drive

The CKPS can fail in this mode only and not give a code

You can see the CKPS on your tach if you can view it during engine starter rotation but is not always at failing point

Ask the parts store if you can try a CKPS and a return if not successful

 

Thanks! I'll check this out and get back for a update.

 

I'll be gone all day Tuesday

Parker has left the building

One way to gauge the bypass on the FPR is the temperature difference between 2 examples , in theory

you can pull the vacuum line off the FPR and ensure it is dry

The CKPS is a fixed position and easy to swap , clean the face of the sensor as this can effect the signal

 

Any tips on how to find a girlfriend who likes X300s, and has two??

 

I'm back

You may notice the fuel pump only runs for 4 seconds then off when you rotate the ignition key

You can place your finger on the fuel pump relay to verify it is closing and making power contact

This is by design

Once the ECU see engine rotation by the CKPS it will command the pump to turn back on for the duration of your drive

 

Hi,
I just saw the video and I remember having almost the same symptoms when I had a failed coolant temperature sensor. The revs were up and down and when it was close to stalling the transmission light would come on.
I notice that the Coolant light it also on, it might be worth checking that the sensor cable is connected to the overflow tank on the left of the engine bay. If it's connected ok, there could be some other coolant related issue.
Hope this helps.

 

the coolant temp sensor ( 2 wire ) can be checked with a meter against a chart on page 64 and 78

You can tap on it to get it to fail

It is the coolant temp sensor that switches your engine regulation between open loop and close loop

http://www.jagrepair.com/images/Trai...20-%202000.pdf

 

I have now replaced the fuel pressure regulator and the crank position sensor.
But it still doesn't run right. It will start and idle and drive if you don't really hit the gas hard. No issues then but once you want to get like half throttle then it starts to sputter and miss fire. the only thing I can think of is that when I changed the fuel pump I didn't replace all the hoses that a video I saw after changing it said that you should do incase they have a crack you can't see because the hoses live under the level of gas.
So that's where I'm at. Pure frustration I tell you. The gf wants her first OG jaguar back so she can cruise in it. So anything that people can think of or have had this issue before would help. I've got to check the fuel pressure and that should tell me if the fuel pump has leaking lines.

 

Checking the fuel pressure would be a good start.
While I was investigating my coolant temperature sensor problem the car ran like yours and I went through the following.

Test the Coolant Temperature sensor (try just removing the cable)
Check clean/replace the spark plugs
Check for oil in the spark plug wells
Check the coils look ok and no cracks (though could still be faulty)
Check and clean the 2 harness connectors down by the screen washer bottle (corrosion risk)
Check the ECU connectors for water ingress and corrosion on the pins
Clean the MAF sensor
Check the intake air temp sensor

I would suspect failed sensors or corroded connections. The engines are pretty solid.
Hope this helps.

 

A tangential thought, but have you checked your transmission fluid level?