Bought a 2000 xj8 about 6 months ago. 100,000 miles. First two months went great. Then my throttle position sensor went out so I replaced it. In the meantime the abs unavailable, Trac unavailable, and gearbox fault lights have all came and went. Remove battery cable and it was good for a week or so. Tried to start it yesterday and it refuses to. Undone the battery cable like I usually would in this case and left it off for about 30 minutes, tried to start again and still nothing. The car runs great when it wants to start. Transmission shifts great. No loss of power. Just had a full tune up about a week ago. So if anyone on here can help me out with what could possibly be causing the messages to show and why it won't start I would greatly appreciate it.

 

Start with a new battery, then pull codes.

 

Need more info.

Does the starter work?

Does it turn over but not start?

Or not turn over at all?

Could be a bad battery, bad grounds or other connections, inertia (impact) sensor, fuel pump, etc., +100.

As was said, get it running, if you can, and pull some codes.
Vector

 

Definitely sounds like these cars require a good, strong battery. Most auto parts store testing is insufficient and can give a false sense of the true condition of the battery. I just bought an '03 XJ8 with 100K and while I'm not having these issues (yet), I'm going to replace the battery ASAP.

Can anyone tell me the locations of all the critical ground connections on these beasts? Long time British car owner and I know how important they are and all the gremlins they cause if not good and solid.

Thanks for the help!

 

Stared works. Turns over but doesn't want to start. Pulled the codes and changed throttle position sensor. But still same problems. Going to try a new battery and see if that fixes it. Thanks

 

STOP! You are chasing the problem by throwing parts (and $) at it.

Please post the codes you have pulled here!

Do not depend on the local auto parts store or the internet to correctly interpret the codes for your jag.

Give us the info we need and let us help you.
Vector

 

Download the manual for your car from the "sticky" section at the top of the x308 forum page. All your ground points will be listed in the manual.
Vector