Engine Mechanical problem
2000 Jaguar XJ8 V8 Two Wheel Drive Automatic 114000 miles
My 2000 Jaguar XJ8 has had two recent incidents of failing to start, even though the battery is strong and well charged. The first time, it just cranked but did not fire. I had it towed, but when the tow truck dropped it off, it started right away. However, I took it to a local garage that specializes in European cars. They scanned the codes, but there were no faults recorded. They tried to reproduce the fault, but were unable to. It then ran fine for the next two weeks. Then, this past Saturday, the problem cropped up again, except that this time it fired but would only run weakly for a couple of seconds and then the engine died. I tried starting about six times and it was the same each time. Had it towed home again, and this time it would not start when the tow truck dropped it off. This morning (Monday) I called for a tow, and while waiting for the truck, tried starting it again. It started first try, with no hesitation. Again, the garage scanned the codes, but there was nothing. The technician suggested maybe the crank sensor was bad, but said he would try to reproduce the fault. I'm not hopeful that he will find anything and wondered if you guys have any experience of this?
I would have the technician check for good fuel pressure. Sounds like maybe the pump has an intermittent problem? Bad wires/connections to pump or pump maybe getting weak when hot? This will not set fault codes
May, 11, 2010 AT 4:30 PM
Since posting my question, I have taken the car to a mechanic. He diagnosed the crank position sensor as being out of spec - the signal from the sensor was " erratic.&Quot; He said this device tells the computer that the car is cranking and commands the computer to turn on the fuel to the injectors. I hope this is the real cause and that the problem is now fixed, but only time will tell.
May, 12, 2010 AT 4:06 AM
This could indeed have been the cause of the fault ? but generally (not alway's) this will set CKP fault codes on ECM and also misfire codes .. I hope this was the cause of your fault ... please keep us updated !
May, 14, 2010 AT 1:33 AM
Hi Dave, turns out it wasn't the cause of the fault. Came to start the car yesterday evening, but it only cranked over at the first attempt without firing. A message came up on the mileage screen, " Engine Failsafe Mode". Tried it again and she started. Today, I took the car back to the mechanic and this time he got a code, P1111. He told me this had to do with a faulty idle control valve. Funny thing is my daughter had the same fault on her Lexus RX a few months ago, and after some denials that nothing could be found, her Lexus dealer eventually advised of the same diagnosis. Changing the component on her vehicle cured the problem. My mechanic called someone - a dealership, I believe - and read the part number given by the diagnostic program. The person on the other end of the phone told him the part was discontinued. That sounded weird to me, since the car is only 10 years old. The mechanic then suggested trying to find it on the Internet, or going to a junkyard! At that point, to use a time honoured phrase, I made an excuse and left. Then I called the local authorized Jaguar repair shop. They said they had the part in stock and could fix it, but only after running their own diagnostic. So I left it with them this afternoon. It will cost more than the other guy was going to charge, but in this case it will be well worth it. Will report back on future developments.