1999 XJ8 PROBLEMS STARTING!

1999 XJ8 with 85,000 miles turn the key and i get STABILITY CONTROL FAIL or something like -PECUS also came up. I haven't turned it on for a couple of days and when i did it dosen't start.
Everything works radio, dash cluster, head lights etc.
When i do try the other thing i get is SYSTEM CHECK.
If you have any ideas or suggestions i appericate them thanks-

does it crank over or do you just get dash lights on and errors when the key is turned?

All i hear is a click when the key is turn then the error code STABILITY CONTROL FAIL comes up right after... some electrical things seem to be acting up also // alarm sounding on a low pitch, the door lock need to hit the remote button a few times before it locks, then the sound it makes onced locked a real low beep.
not sure if it has anything to do with it or multiple problems.
 
Thanks for the help sounds like i'll need to get a JAG tech over here!
 

sounds just like a dead battery ... the stability control error is from voltage to low.. check ur battery ..or it cud be a loose or corroded or burnt power studs which is very common.

i had a bunch of crazy electrical problems that had 2 mechanics tell me they've rarely seen these problems, and they eluded that it was going to be a very expensive repair because it would take a lot of trouble shooting.  It seemed like the problems happened right after i added a radar detector and the forum people thought that was the cause and not just a coincidence.

issues
a)traction control failure - it would get thrown almost always at low speeds
b)car stalled sometimes, typically at low speeds or while stopped.
c)the car alarm and all other electrical accessories (such as the trunk) would sometimes not work after turning the car off - also the car wouldn't restart...normally after about 10-15 minutes, then it would finally work.  I found myself tied to my car at the airport while waiting for a flight, and my girlfriend had to take a cab from my car to a job interview after she stopped for coffee....not fun


fix
replacing the battery cut the frequency of these issues down 80%.  I was made aware the voltage was off on the alternator, and it was suggested i replace it.  On my way to take the car in, i was .5 miles away from Ken's Austin British Motorcars location, and the belt to the power steering broke along with the tensioners.  Replacing the tensioners and belt fixed all of these problem listed above, also my car ran smoother.

DR

Drog: Regarding your slow speed stalling problems - my '99 XJ8 did the same thing. My mechanic performed a fuel injection system cleaning and replaced the fuel filter, but the problem persisted - and got worse as time went along. Acting upon the advice of a fellow poster here I checked the throttle plate and found it covered with tarry deposits. I bought a spray can of B-12 Chemtool throttle plate cleaner (around $2.50 at most auto parts stores) and fixed the problem. Other causes can be a bad MAF sensor or a problem with the throttle body itself. A local Jaguar tech told me there are "a lot of issues" with Jaguars and the fuels sold in the US. I was advised to skip the cheap stuff and run either Shell or Chevron gasoline.

One tip: When cleaning the throttle plate, use a cloth instead of a paper towel. The spring on the plate is very strong, and if you use a paper towel the throttle plate could close and tear off a piece of the paper and drop it into the intake.

Since cleaning the throttle plate is easy and cheap, start there and see what happens. All you need is an 8mm socket to remove the two retaining  bolts from the plenum cover and it lifts right off to give you access to the throttle plate. It took me about five minutes to clean mine because it had a lot of deposits on it. Since I performed the cleaning the car has not stalled, and a little "hitch" the car once had when I pressed the accelerator has disappeared.

orca99usa,
 
what do the throttle plate and the plenum cover look like?
 
pardon my ignorance...i'm more comfortable playing around with the interior of the car, versus working under the hood....
 

Follow the tube from the air filter. Two 8mm bolts hold it down onto the throtle housing. Clean the plate under it. Remember to put the rubber seal back on the tube when you done. 

I've changed the battery negative then postive // postive then negative when it put it back on cleaned the power studs had some corr. on them put the vent tube back on since turn the key no more STABILITY CONTROL FAIL error code. sounds like it wants to start up but still dosen't.
I'll check the throtle body housing since in the past it has been replaced.
 
Again thanks for all the suggestions and help it's appericated-

if it wants to start and it cranks then it may seem to be flooded .. put your gas pedal to the floor and crank this shuts off fuel .. and when it starts to fire release the gas pedal allowing fuel to flow.

When you clean the throttle plate, make sure to hold it open a bit. You may have some deposits on the sides of the throttle opening that won't be cleaned off if you just spray it with the throttle plate closed. Mine had deposits on the leading and trailing edges of the throttle plate that extended onto the throttle opening. If you don't clean the sides of the throttle opening your throttle plate may still stick.

Thanks for the help jag genius that's all it was. The car is starting up. Thanks for looking out-

Hah! Genius, gotta love it.

YEP!