Try starting it with MAF sensor disconnected - will eliminate and its free.

 

I will give it a try. Thanks. Also should mention that it's throwing misfire codes on all of the cylinders...the car is currently 5 hours away and I want to prep as much as possible before I go to get it

 

I'm surprised that this is the ONLY suggestion I have received from this question. Surely there is someone else out there that can offer me alternative solutions...Damn y'all, I'm gonna be traveling 5 hours in just a few days to go try to get this car home...

 

Are you sure you didn't put diesel in it by mistake.
For a car to start but then die sounds like the fuel pump is priming at ignition but not continuing after start.
You need to get codes read. Sorry to be so vague but due to the complexity of the circuits it could be anything.
You can download the wiring diagram from http://www.jagrepair.com/images/Electrical/XJElectrical/2004 MY XJ Electrical Guide.pdf and the OBD codes from http://www.jagrepair.com/DTCforms/X350_P_DTC_OBD_II.pdf

Roger

 

Yeah, I.m pretty sure I didn't put diesel in it lol that would definitely cause problems.

 

Any chance it could be a malfunctioning key/anti theft issue? How do i reset that system just to eliminate that as a possibility?

 

I do not think it can be that as the car cut out whilst driving and if it was associated it would not occur until you recycled the ignition.

Roger

 

Another thought is that it could be the CKP (Crankshaft Position Sensors) or the H02 Oxygen sensors as you state you have misfiring.
What were the codes being thrown. It would help if we knew.

Roger

 

Well after I had it towed to my friends house I put a code reader on it but I didn't write them down. I do remember the pertinent ones were the misfire codes. Also, as far as the ckp or the oxygen sensors, I m not sure those two things would cause it to stall out going down the interstate at 70 mph...

 

There is another possibility that of the Alternator. If the alternator is not charging then the engine could start and then just die.

Roger

 

I thought of that, but wouldn't the battery have run down to some degree causing the starter to drag or the lights to dim? It's turning over strong and the lights are bright. Also, if the alternator had suddenly went bad, surely the car would not just die going down the interstate would it?

 

If the voltage required by the functions of the car is below parameters then the vehicle could shut down irrespective of the condition of the battery. The ECU reads alternator output not battery condition. I know its a long shot but something to think on.

Roger

 

You fill up and then a short while later you end up with a non running engine with miss-fire errors. I would be checking the fuel first

 

+1 for that diagnosis. Otherwise it's an amazing coincidence.

 

Man, I unplugged it and it cranked right up. $85 dollars for a new one from autozone with a lifetime warranty! Drove it home without incident. Thanks so much for your simple wisdom my friend

 

You're welcome my friend - glad to have helped. Often the simplest solution is the right solution - many people start looking too deeply!

 

it does sound like a fuelling issue - was it raining by chance ?

the fuel pump doesn't work flat out all of the time - there is a control module which decides how hard to drive the pump(s), based on output from the fuel pressure sensor in the fuel rail. It just detects the pressure and when it falls below certain levels, it drives the pump(s) a bit harder. I say pump(s) because XJR has two and a separate box to drive the second one.

It sounds like you have a code-reader available, why don't you try repeating your tests based on what I've told you above.

My XJR suffered from a corrupted wiring harness around the back of the rear subframe, which had become chafed internally as a result of the rear subframe having been removed and mis-handled. the loom goes to the tank aperture and the around the axle before going to the second tank aperture. worse when it rained.

and there's also the scope of the different tank venting system you have stateside, of which I don't know the specifics. Other than its not really an option to run without the filler cap on