I've started to have the following issue over the last few weeks.

I get in the car, turn the ignition on (every lights up as it should), turn the key to crank...... absolutely nothing happens........ for about 2 to 3 seconds. Then without anything changing, the starter engages and the car fires up perfectly. I am not jiggling or moving the key at all in this 2 or 3 seconds, I just hold it in crank position.

My mechanic had the car a few weeks ago (for something unrelated) and he said it wouldn't start, so he changed the starter relay and claimed that had fixed it. I talked to him today and he confirmed he only held the key at crank for a second, and not any longer, so he didn't know if it would have started as it starts now. The interesting part about this is it shows the starter relay had something to do with it, because when he changed it, the car went back to starting instantly, but has since degraded again.

As usual with a Jaguar, and in particular the XJS, the fault is intermittent, and refuses to happen when you want to show someone, or record video of it, or have a second pair of hands hold the key in the crank position as you fiddle with things to see if you can provoke the start faster.

I've removed the relay, cleaned the connectors, checked the wiring, re-seated the relay, but what I can't understand is what changes during the 2 or 3 seconds that finally enables the starter to engage. Lazy relay ? I don't know, I'm making stuff up now.

I can live with it..... I'm just concerned that the 2 or 3 seconds gets longer and longer and eventually it never cranks, although at this point I have a better chance of finding the fault because its terminal by then

Just wondered if anyone else has seen this.

 

If you have a look in the Boot/Trunk, where the Leads go on the Battery.

You can see a couple of brown wires that push into a connection on one of those Battery Leads.

It is very easy for those push in wires to get dislodged, the only problem being that it isn't immediately obvious just by looking at it.

In the event they have worked loose, the Engine won't turn over though sometimes it might do so, depending how loose they've become.

If you jiggle them about or better still give them a clean, then I've got a feeling that this might solve the problem.

 

Hmmm.... very interesting..... I changed the battery a few weeks ago. (and of course that means fiddling with a fore mentioned cables) Guess what I'm going to go check immediately......

 

Cool, let me know..Mine does the same.

 

@orange

I inspected, cleaned and reassembled the connector you mentioned. The car was starting fine before and after (of course it was) so at this point its not conclusive, but it was good preventive maintenance anyway.

@Malc4d

I'm glad you are having the same issues, in a sick and twisted kind of way, wouldnt want to wish bad things on people! Hopefully we can help each other. We both have 92 V12s which have enough subtle differences from prefacelift or later 6.0 cars to make them that little bit more annoying to debug.

Question.... when yours wont start, do you see the "park light" indicator in your instrument cluster light up? Mine will consistently do this and the instant that light goes out the starter engages. Its too early in the morning but I am thinking there is something strange going on with the convertible top circuit, because that circuit looks at both the park brake switch and the gear selector switch.... maybe there is something adrift in the gear selector switch that momentarily supplies power back into the handbrake circuit (briefly illuminating the "park brake" light), then it fixes itself and power goes where its supposed to go, and enables the starter. I will be using the car today so if it misbehaves I may be able to do some more debugging. Have you ever tried wiggling the gear selector around when its not starting? Has your ever not started at all?

 

That connection, can also affect the lights on the dash in the way you described.

The trouble is the Battery lead is too stiff to jiggle about but it still looks to me like the problem may be in that area.

That's where it was on mine, turn the key and no lights!

Jiggled the wires on the Battery in the Boot/Trunk.

Turned the key, lights came on and then the engine turned over and She Started and has done ever since.

Might be an idea to also look at the block connection just above it.

 

I think that's a difference in our case....... Everything else comes on perfectly..... It's just the starter, ie not complete electrical darkness.

Of course the 3 times I have started the car today it's been behaving..... It's probably waiting till it's raining, or I need to go to the airport or somewhere urgent......

 

I think you might be OK now, as once the problem has sorted itself, it doesn't seem to come back.

Well hopefully not.