Over the weekend I've been cleaning contacts in a probably futile effort to correct this electrical problem, though often times an intermittent problem is simply a poor connection..like tapping my coolant gauge to wake it up.

I've taken a short video this was the second startup so not as bad, but the flickering stuttering to start is getting worse I'm really hoping it isn't the starter itself, the only other old component I can think of are the distributor leads which are at 5yrs/80,000km. Otherwise the car runs flawlessly.

 

Hi Vancouver

It could be the Fuseable Link

Common Problem easy fix!

If you take a look at the Photo you will see the Fuseable link which looks like some sort of Plastic Block 'Thingy' on the Lead from the Positive Terminal of the Battery

This is very 'Twitchy' and can lose connection if disturbed like for instance moving the Battery or even looking at it the Wrong way! (its really that sensitive!)

More often than not its just a case of flexing the Battery Lead each side of the Fuseable Link with your hands and also pushing it together to make sure it hasn't come apart and hopefully that should fix the problem, as long as you remember to never go anywhere near it, unless it goes wrong again

 

From down here, and 7 coffees down.

BAD earths, and thats a good 2 days work to do the main ones.
Flaky Ignition Switch Electrical section, getting very common now.
+ve battery lead connectors, firewall etc etc need a good clean, maybe.

Nothing to do with HT leads.

 

Thanks both of you, my battery cable 'link' has a slight cut in the brown wire, no battery cover so maybe its been knocked around. What is the link for exactly?

I've had the loose key switch issue on my old BMWs its about as common as the sunrise is there a trick to correcting a loose Jaguar unit or is it simply worn out metal bits?

On the BMWs after getting tired of starting the car with needle nose pliers I just tore the wires out and did a push to start sort of knob but I wouldn't that on the XJS.

 

Hi Vancouver

As I'm not an Auto Electrician, I have no idea!

But what I do know is that this Fuseable Link can give you a problem in Spinning the Self Starter to turn the Engine over, which can range from a bit of hesitation before the Self Starter 'Kicks In' (like is happening on your Car)

To a Full on: Nothing happens! to make you think your Battery has gone Flat

Where because of the way its leads bend round, this alone can cause enough Tension for this Fuseable Link to come apart, even by such a small amount that even on close inspection you might never notice that anything was wrong

So often it is just a case of pushing its plug and socket firmly together and then arranging the Battery Leads to take out as much Tension as you can and then when you've got that sorted so the Engine Spins first time you turn the Key

Do anything and everything to make sure that those Battery Leads do not get disturbed

 

The key switch thingy is 2 sections on the Jag.

The mechanical bit, which can wear out, but rare as far as I know.

The electrical section, attached TO the mechanical section with a TINY philips headed screw.
This electrical section is the root cause of many odd behaviours. Separate it from the mechanical, open the tabs, place in a freezer bag, and CAREFULLY open the thing. There is a spring loaded pawl inside that gravity just loves, hence the freezer bag.
Clean the dried out goo, polish the contacts, smear some lube inside, reassemble, and recrimp, refit, test, drink beer.

If that fixes it, goodo, if not plan b,c,d,e,f etc.

 

I can't believe the primary power supply cable that makes the whole thing start, etc is simply sliced? in two then pushed back together with a plastic/rubbery socket...what an idiotic typical Jaguar thing.

So I pushed the cable back in about a quarter inch, seems to crank on like a lightswitch. Will see tommorow morning (colder) will effect anything. Thanks again!