RE: 2003 XKR 4.2 SC

Sirs,
Car cut out en route.
Has rough idle, normal above.

12v to pump, pump OK. Car will run on residual fuel from motor test then stall, sometimes it will stay running others stall.

Fault codes are fuel pressure related P0191,3 (approx).
Can anybody assist?

 

Are both pumps good?

In mine the intank wiring for the main pump failed but I could start it over and over due to the priming/SC pump still being fed juice. There are posts on here about reversing the SC and main pump wires going to the to of the tank(the wiring goes from your drivers side[your UK right?] to the top of the tank). If you reverse them and the car runs well, then you have either the wiring in tank to the primary pump or the pump itself bad.

When you have the fuel pressure tester hooked up and you put the key to on, what does it do? Does it build pressure? If it does, does it drop off when you start it and the car dies?

Also, Coupe or Roadster. The coupe it sounds is infinitely easier to do wiring and pump replacement than the roadster.

 

80's thanks,

Yes RHD Convertible.
Jtis says only one pump for 2003 Jaguar 4.2 XKR

 

Sorry, missed the other question. Sometimes it builds pressure others not, is that the ECM telling it to do so?
Many Thanks.

 

80's,
Just looked at my JTIS (disclaimer) and your 2000 model is listed as having two pumps and two relays, one in the trunk fuse box and one outside of the trunk fusebox.
The 2003 variant in discussion has only one pump, the wires from the pump are white and black (presumably below the tank fitting) then they are yellow and red/yellow, and then red and red/yellow, which is where 12 volts was placed this morning (there are also more wires in the plug). The red and red/yellow and additional wires then enter the insulated loom (will look into this part more), according to the wiring diagram the wires then go to a module then to the ECM plug via pin 25 and pin 27 (white wires).
Helpfully, JTIS does not list the location of the module or the whereabouts of connector P101 which is referenced when performing fuel pressure sensor tests.

 

I would suggest testing the fuel pressure sensor, sounds like it is having a problem. This system is nothing like the earlier models, it has a much more sophisticated pressure control system since there is no return line, the pump has to have its speed varied to hold pressure (the reason there is only one) ..

 

+1
The codes point to the fuel pressure sensor or the connectors/wiring connected to it.

Check out section 303-14 'Electronic Engine Controls' in JTIS, it lists likely causes for those codes and directs you to some tests you can do.

 

You can easily eliminate the pump as a possible culprit by unplugging it from the fuel pump modulator and applying 12 volts directly to the wires that go to the pump. That keeps the pump running continuously. Don't drive it like that, but run it long enough to verify that the problem isn't the pump. Another possibility could be the fuel pump modulator.

The modulator is located in the trunk on the right side. You have to pull off the cover that surrounds the CD changer to access it. It's all the way forward and down low, just above the battery. If you want to check it I can tell you which pins to stick the jumper wires into to make the pump run.

 

Sounds like the same symptoms my ailing car has. 2003 XKR. Left work today bound for the Burger King 2 miles away. Car drive fine (however at startup I did notice an extremely slight bump in the idle I had not noticed before) I drove unusually (for me) mellow to the BK, parked and shut it down. After about 3 minutes of listening to the end of a segment on NPR I thought better of eating a burger and decided to go next door where I could get a salad.... Car would NOT start. It would stumble a bit and "try" to start - but no "fire in the holes." I checked the codes but the car's computer had not set on yet.

Got a friend to flat tow me home after work.

Tonight, after the fear of timing chain death subsided I started doing some checking. After finding the Blue cap on the fuel rail schrader valve I pulled it of and pushed the valve release. I noted that there was no residual pressure. I turned the ignition on for a few moments - listened for fuel pump running but heard nothing. Checked the valve again, but no pressure. Tried starting it again out of desperation - this time letting the ignition stay on for about 10-15 seconds BEFORE I cranked the starter, and low and behold, it started.... Barely. Engine stumbled and came to life settling in at a calm idle - for about 10 seconds, then slowed and stumbled to a stop again. Again, a check of the valve showed no pressure. I tried the same start procedure again and it fired up again - same as before, stumbling to life... I noticed it would NOT rev beyond about 2500 rpm - it sounded smooth till then and as it came up to about 2000rpm it sounded weak - like it was leaning out. I quickly got out of the car and just before it stumbled to a full stop pushed that schrader valve again and the smallest little drop of fuel appeared just as the engine quit.

I checked the codes again and THIS TIME I got the P0191 fuel rail code.

So here I am, thinking Filter, Regulator, Fuel pump module, or $$$$ Fuel Pump!

Any guesses as to the most likely culprit?

Hey Reverend Sam, what's those two pins back at the fuel module to force the pump to run? I could start there I suppose...

What a pain!

-Ward

 

Max, I hope this is of some use.

Plug used for motor test (red/yellow (top left)and solid red(bottom right)) Additional wires are for unfound fuel tank pressure sensor.

Fuel tank pressure sensor plug -unused.


Module.




Tests:

 

Thank you for the details and the great pics XKR!

It's 9pm Friday night, but this is the first chance I've had to jump into it since 3 am this morning. I'm gonna run some tests. We'll see..........

 

The exact same thing happened to me this past Monday. I could start car over and over again, even rev it, but it would shut down after 2 or 3 seconds. Same code. First, we discovered supercharger had broken, second, one of two fuel pumps was inoperable, third, after fixing first two, check engine light came on with air flow meter coding. Two grand and two days later, all is well.

 

2003 XJR-R. Well now I am very puzzled.... Still no start. I jumped the fuel pump to the battery at the pump/tank connector as pictured and suggested by Member "XKR." I heard the pump run and had solid pressure and flow at the schrader valve on the injector rail - so I tried to start it with the fuel pump whirring away in the tank. No start - not even the stumble I was getting last night. I disconnected the direct-to-pump power and reconnected the pump/tank connector and tried starting again....

Nothing but a couple of stumbles that momentarily sounded as though it was going to start - but the engine did not start. I could not even get it to start and run for a moment like it did earlier in the day Hmmmmmm, Sad moment for me.

I dont think its the fuel filter because when I jumped the power directly to the pump I got plenty of fuel flow out of the schrader valve.

Wow? Where to next?

Member tberg.... Thanks for you input but please elaborate on just what you meant when you said you had a "broken supercharger?' I really dont think the supercharger has anything to do with my no-start situation. But I'm curious about your experience.

Next step anyone?

-Max

 

Rev Sam,
Could you please expand on the module test?

Many Thanks.

 

Anybody: Can you point me to a full "on-line" version of the XKR JTIS that someone has converted to all .pdf or the like? I HAVE a CD Copy of JTIS that I bought several months ago, but it is nearly useless to me - because our family runs Macintosh computers exclusively. We don't even have a "P.C." in the house, and I'm an audio engineer - so we don't use them at work either!

Ahhhhhhhhhhhh! I'm clueless as to were to further my trouble shooting!

I've got to get my baby rolling again.

What a puzzle that probably has a simple solution - my job is to find it.....

 

Does a 2003 XKR have an enertia switch? If so, where can I find it - I've looked every where I could think of, and found nothing.

 

Did you check the driver's side dashboard fusebox?

 

Max,
I can send a PDF.

Inertia switch:

The inertia switch is behind the trim panel to the side of your left foot.

JTIS Inertia Switch doc:




JTIS Fuel Tank Pressure Sensor reference pictures:

 

Thank you XJR... I'd certainly appreciate you sending that .pdf file of the Service info. I downloaded what I thought was exactly THAT .pdf file from another post, but what I received (even though it said it was a .pdf) would not open using ANY text reader I tried... Wasted a half hour desperately attempting to get anything of use out of it.

I feel totally neutered without a service manual for my car! It's driving me nutty!

I cant even figure out how to remove the door thresholds so I can remove the front trim (or kick) panels in order to locate the aforementioned Inertia switch.

How to I remove those thresholds!

Boy, I feel like I am 16 years old an I'm looking at the engine of my 340ci Duster for the very first time! Duuuuuuuuhhhhhhh

Thanks to all for your help

I just refuse to give up.

 

New clues:

I checked EVERY fuse in the car with a VOM and re-seated every relay. All fuses were good.

Bought a fuel pressure gauge and attached it to the schrader valve at the front of the right bank fuel rail. When the key was turned on I could hear the pump come on for about 2 seconds and the gauge read about 5-10 psi within a second or so. When I attempted to start the engine the pressure actually went down - and, of course, it didn't start.

After that, I jumped the fuel pump straight to 12v again - and with the pump whirring away, saw that the pressure gauge still never went above about 15 psi. I did not try to start it in this configuration.

I turned my attention to the fuel filter. I removed it and unfortunately (in this situation) it was perfectly un-restricted. I could blow through it easily - I even cut the can apart, and for a car with 80K miles, it was incredibly clean... It may have been replaced before I bought the car at 70K miles. Now I must buy another.

I put the fuel line from the tank into a gallon jug and powered up the fuel pump from the battery again. I got about a pint of fuel in 2-3 seconds.

So, at this point I believe I have eliminated the pump and filter as causes of the no - start situation. However, I'm still kinda baffled why I never saw more than 15psi at the rail - even when I gave the pump a full hit from the battery???

I'm applying "old-school" thinking to this situation because I don't have a service manual to properly trouble shoot my problem - and "old school" isn't working so well....

I have a compression gauge, and even though two nights ago she started (begrudgingly) and idled SMOOTHLY for about 10 seconds before coming to a rough stop, I suppose I should perform the compression test - just to rule out the busted timing chain ordeal. I still don't think its a timing chain failure.

I'm really at odds here - I don't know WHAT to try next.