Hi there this is my first post on here, i could with some advice or help.
I have just bought a 1999 4.0 XJ8.
Its been fine for the first few weeks but a couple of weeks ago i went to my mates house and when i cam back to the car it wouldnt start, it came up with
Gear box fault, acs fault, trac not available and engine failsafe mode.
I lock and unlocked the car a couple of times and it started.
It was fine for a week then it did it again, but this time i had to disconnect the battery and it started.
Last week it did it again and would not start it had to be left about 3 hours and then it would start.
It spins the starter but just wont fire.
Its not a flooding issue and once started the car does not stall, misfire or do anything it shouldnt.
Any ideas as im out of them.
Thanks Greg

 

how good is the battery Greg?

 

Brand new, thats the first thing i did.
Its got a Bosch silver heavy duty fitted and it still doing it.

 

OK, are you aware that you can read fault codes stored in the cars memory with a cheap OBD reader, this limits info gathered to the engine. To look further into it, you'd need a good Jag independent or main agent with the IDS tool to look into it further. Once you plug the obd reader in, you might get codes that point in the right direction.
My initial thought is a faulty security module, located under the fuse box in the boot, is there any moisture in this area?

 

Not looked at that bit yet.
I have had it on my friends scanner and it threw up some codes although i cant remember what they were.
What i do know is it wouldnt talk to the engine straight away.

 

ok, so we need the codes to progress, we can deal with each and see if it leads to a cure.

 

Hi there i had the car on IDS and frst of all it wouldnt talk to the engine ecu.
It wouldnt talk to it even witht the car running.
When it eventually did talk to the engine, it bought up 7 faults. 3 misfires, i for aux air valve, and then a couple for the lambda sensors.
I cleared the codes and they havnt returned.
The car did have a code in the gearbox which was can bus data to engine fail.
Hope this helps

 

it would have been helpful. if you'd made a note of them, so we could look further into it, still some may come back. Next time you get an engine light and link up, jot them down and report back, how's it running now?

 

Touch wood its running fine, starting and restarting ok.
Just to say it has never bought the engine light on.
Thanks for the help anyway.
If it comes back i will post on here.

 

Just a thought. I've got a '90 MX-5 and a 93 325is that my daughter drives. Both developed starting issues about a month ago. Each would turn over with gusto, all gauges, lights, accessories worked with no issues. BMW would turn over without starting, MX-5, took 5-6 attempts before she'd start. Pulled battery leads on both, cleaned terminals, and lead clamps, coated all with dielectric grease and reconnected. Both cars fire up immediately now. Strange thing was that neither of them showed any physical sign of a loose connection. We'd had some strange fluctuations in weather patterns (Warm then Cold, with 35-45 degree swings) just before all this started. Neither of them showed any codes during or after the issue.