Can anyone help with my 1996 XJR not starting after being laid up for 3 months? Maybe immobiliser issue??

[paulhigginson]

I have a 1996 XJR which was running perfectly before being laid up and not touched for the past 3 months on a friends driveway (144k miles, FSH).

When I went back to it last week the battery was, understandably, totally flat so I removed it from the car and fully re-charged it overnight.

I re-fitted it to the car, the fob worked to lock / unlock it and everything lit up when I turned the key...but on trying to actually start the car, nothing...and I mean nothing!

I fitted new batteries to the fob, just in case (and as per the instructions in the Security System booklet well within the 2-minute deadline), nothing.

We tested the battery - fully charged and all seems in good order.

We tried it with jump leads on for an extra boost, just in case, still nothing...

We've given the starter and solenoid a good tapping / shaking just in case anything had stuck slightly, still nothing.

We tried putting the headlights on full and then starting it and they, and the dashboard lights, don't even dim slightly on turning the key to the starting position, there's not a click or hum to be heard or a current draw to be seen or felt...

All of which makes me think that there's some kind of security system / immobiliser issue going on preventing the car from being started, perhaps linked to the battery being allowed to slowly run flat and staying flat for a few weeks prior to it's removal, charging and re-fitting.

Any ideas or help from anyone would be much appreciated before we have to start taking things to bits!!

[Alastair]

Try giving it a charge "In Situ" for an hour just an idea no firm evidence

It might be the immobiliser but don`t know how you fix that

Good Luck

Alastair

[Adam]

This could be a tricky one.

Alistairs idea sounds like a good one, I can't help much but chances are it will probably be the immobiliser.

Good luck with getting it going. Let us know how you get on.

Adam.