I posted this a few years ago, got the problem fixed and now it's back.

I'm wondering if anyone having an XJ or XJR, year 2000 vintage, or in that series of cars, has had problems with the car starting after driving for a while.

I had this diagnosed as a starter solenoid that is positioned too close to hot engine parts or exhaust manifold. No suggestion or attempt to relocate the solenoid was made at the time. The fix purported to be a thorough removal and cleaning of all battery connections and grounds, the replacement of a relay in the array found in the left front engine compartment. I had been told that the battery was fine, and though I just had the battery replaced and even charged it when the problem reappeared, it still persists. I can usually start the car after driving and then waiting 10 to 20 minutes after the car has either cooled or the problem has timed out, if computer related. The mechanic doing the work was a former dealer service writer and said that he'd seen many such problems in this model line and knew where to look to fix it. The fix lasted for about two years and now it's back and he's moved on. Any suggestions would be appreciated.
THANKS!

________________
2000 XJR (added by GGG)

 

I've moved your question from General Tech Help to X308 forum. Members here with the same model will be able to help.

Graham

 

To cut the problem in half the next time it does not start there is a shrader valve on the left fuel rail that should be charged up to I think 43 PSI on this engine . If there is a lower of no pressure then it would be fuel control related .

You might be on the border of putting yourself in a borewash condition if the pressure is low and not lighting off leaving unburnt fuel to wash the cylinder walls . How you were able to overcome this condition maybe or maybe not be explained after you have a correct fuel pressure or din't know that you were holding the pedal to the floor that by design cuts off the fuel injector spitting while oil is brought up from underneath the piston to restore the ring seals .

 

The condition you are describing sounds a lot like "Heat Soak". The XJR's and XKR's occasionally suffer from it. The engine management system uses the AIT (air inlet temperature sensor) to determine fuel enrichment, you will notice at start up on a cold engine the idle is usually around 1100 rpm and settles back down after warm up. That is the AIT working.
You need to get a cheap infrared heat gun and take a couple of readings. Take the Jag out for a spirited romp and then shut down. Take a reading of the radiator temperature and a reading of the intercooler temperature. If there is a considerable difference you will need to do some further checking.
First turn the ignition on and without starting the engine check that the auxiliary cooling pump is running. If you can hear it running or feel the vibration of it running then shut off the ignition and open the intercooler coolant bleed plug and make sure the water level is up.
An air bubble in the intercoolers or a defective auxiliary cooling pump will cause heat soak.
One last thing the starter solenoid is integral to the starter motor and not remotely mounted.

 

Are you saying the car will not crank ??

Also -- you say it was fixed .. but you still had to wait ... that's not fixed.

post is not clear

 

I had a similar problem on another car (not a Jaguar) that turned out to be the coolant temperature sensor. It was sending improper readings and therefore the computer was sending an improper fuel amount. It may not be what's happening on your car but it's really cheap to rule out. The sensor is very easy to get to and change plus they don't cost very much.

If you have some way to actually read your coolant temperature (I use an UltraGauge) then you can see if the sensor is sending the wrong info. If it's way off it should be obvious. If you compare infrared thermometer readings to the gauge then you could verify accuracy that way as well, with some degree of accuracy.

Just another option to explore...

 

To clarify, on the turn of the key to start, the engine will not even crank. On shut off after driving, the normal protocol would have the steering wheel and seats(?) retract a bit and the sound of various systems shutting down, radio antenna retracting, etc. These protocols don't happen when the car is about to experience the non-starting on the next attempt. That is, until the car has sufficiently cooled down so that the engine will crank and start as normal. I have taken to carrying a spare battery in the trunk to jump start the car when it won't start and that works every time. The existing battery installed in the car is but a few months old and I've already charged it to full capacity. Also in the non-start condition, the wipers will sweep across the windshield and stop in mid-sweep at various points on the windshield.

 

With your observations on the difference in a warmed up battery and a cold battery sounds like a open cell on the battery as your installed one warms up and expands in size . Even though it is new means nothing today . Remove the battery and with a meter on it tap on it and around with a 2 X 4 and watch your meter jump around .

 

I've had similar issues with a no-start problem. I would turn the ignition to start and would only get a click, then after retracting the key from the ignition, the lights would flicker, the dashboard would dim down, and sometimes the windshield wiper would activate.

It may be worthwhile checking the inertia switch in the passenger footwell. You will have to remove a small plastic panel to get to it. When you experience the no-start issue, check that your inertia switch is in the down position, by pressing down on the button. Then try starting the car.