Hi Guys

Starting the Engine from Cold She will run for about 10 Minutes perfectly fine and then the Engine will Cut out just as if I've turned the Key and switched her off

And will not start again until the Engine is completely Cold, when the same thing happens all over again

Fuel Pump Works OK

There seems to be a lot of People having the same problem

Which in my Case Coincides with the Alternator Belt Snapping (Coincidence or Not?)

CPS VR Head looks ok but who knows?

Any ideas?

 

Are you getting fuel at the rail?
The swirl pot could be partially blocked?

 

Man OB yet another new issue....hope you solve it, like we know you will, so when it happens to us, we know what to do.
Probably not ignition amplifier or coils since one bank would still run.
Fuel starvation would make it stumble prior to dying/stalling. And since you said it's like you switched it off...instantly dies.
Therefore I would bet you damaged the CPS somehow. They are about $60 at Oreilly's here. I'd send you a used spare if they were a lot more $$$.
Other than that, maybe something is heating up and opening a circuit????

 

The 10 mins and won't restart until cold are your important clues. In other words, it's likely temperature related.

It could be a damaged or failed sensor that goes open circuit when hot.

Another thought, perhaps the alternator belt hit a wire or a connection such that now heat expansion causes an open circuit. IIRC, there are only three Primary Inputs on a Marelli -- Crankshaft, Flywheel, and Manifold Pressure (MAP).

It might be worth trying a start from cold and immediately giggling the CPS wires and following along the harness to see if you can identify a weak spot or see if the engine shuts off or stutters.

 

Had exact same issue, crank sensor is highly suspect...or the rear one I get them confused but best practice is to do both on the marelli cars. Mine would run if I kept up the highway speed on a cold morning, if I stopped the car would heat up and the sensor cut out haha!

 

Hi Steve

That was a really good idea! and I did check the Fuel Pump this Afternoon and the Pump is delivering loads of Fuel at the Rail but again I'm ruling nothing out and if all else fails may revisit the Swirl Pot just in Case

BTW! You've got me watching re-runs of 'Lovejoy' nearly all the Full Episodes are on YouTube and it was Filmed not far from me where I live at 'Orange Blossom Towers'

There were Six XJS's used in the Series plus XJ6's a TVR Chimera and even a White 'etype'

The Young Lady in that Photo is Caroline Langrishe who is one of the main Characters and plays the part of Charlotte Cavendish who is 'Lovejoys' Love interest

She started off with driving a Red 1991 Convertible (facelift) 4.0L Crossover which had Latice Alloys and then later on switched over to a Red 1993 Convertible 4.0L with 4 Spoke Alloys, which also had a Telephone the size of a House Brick

Which was built in to the Central Arm Rest, that sort of had me wondering if the 1991 may have broken down and then they may have swapped it for the 1993 maybe hoping that we wouldn't notice

Then later on in the Series She can be seen driving a Blue 1994 4.0L Convertible

I'm loving watching these re-runs, as apart from the House Brick size Mobile Phones, this is a very enjoyable watch that has really stood the test of time (with more XJS's than you can shake a stick at)

And for you Guys over the Pond, this was all filmed on Location in Suffolk, which looks exactly the same today as it did back then

 

Hi Fla Steve

Good Thinking!

As it seems more than a coincidence that everything was OK until the Alternator Belt 'Snapped' and so the CPS almost certainly must have got hit with the Belt when it broke

Where instead of falling off, what was left of the Belt had wrapped itself around the Crankshaft Pulley, so I'll try and pick up a New CPS Tomorrow

Thanks for the offer that was a very kind thought, although I'm hoping that they won't be too expensive down my way

 

Hi Mac

Cheers!

I don't think (am hoping) that a New CPS is not going to be that expensive, so I'll try and pick up a new one of those Tomorrow DBC12508 (I think it is)

 

Hi VancouverXJ6

After that Belt Snapping incident, I agree the CPS is sounding suspect but I was reading about one Guy who spent $1,000 on Parts and still couldn't fix it!

So we'll have to see what happens when I put on a New CPS

 

You could remove the wire first and cut the shielding away? It should be in a plastic sleeve but maybe...possibly You can verify it is damaged before tossing $100+ at the part. You might see where the belt hit it as itl be polished or scuffed abit.

Though its entirely possible its an original and simply failed at the time of your other issues.

As for spending only $1000 on parts where can I get this deal? Thats cheap!

 

Hi Guys

Thank you all for your help

New Crank Position Sensor and New Water Temperature Sensor arriving tomorrow with any luck and then we'll see what happens

Alex

 

Hi VancouverXJ6

Can't see any damage to the Wire or even the Sensor, so maybe its just packed up

New one arriving tomorrow with a new Water Temperature Sensor

 

HI Guys

When I removed the Water Temperature Sensor, No Water came running out and the Probe on the end of the Water Temperature Sensor was dry!

Although the Radiator and the Auxiliary Tank were both brim full of Coolant, so it would seem that Coolant isn't circulating in the Engine

Could it be as Simple as needing a New Thermostat?

Maybe this could explain why the Engine always cuts out just as the Temperature Gauge is starting to move and may not have anything to do with the Alternator Belt Snapping or the Crank Position Sensor

Which was such a coincidence that they seemed to be related to the problem

 

2 thermostats OB, one each side.
Make sure they have the jiggle pins in and mounted at the top.

 

New Water Temperature Sensor Fitted, no difference still wouldn't start

New Crank Position Sensor Fitted which only took me 6 Hours! (Yes! SIX HOURS!)

Turned the Key and She Started on the Button and ran for 20 Minutes without any problems, so when She Cools down I'll try her again and then see what happens

Full write up including Pics and why it took so long for me to fit the New CPS, to follow on my 'Cherry Blossom' Restoration thread

 

Goodo.

Simple cars these V12's, agreed Alex??

Time is unimportant, whatever else would you be doing, honestly. Shopping, Drinking, Spending money, Mowing lawns, nothing as special as working on a V12 for sure.

Still, well done from Downunder.

 

Hi Grant

Cheers!

If I can fix it then it must be simple but trying to thread the Wire through from the CPS to the Loom was an absolute Nightmare, which made changing the Plugs on an XJS seem like a 'Walk in the Park'

 

Jaguar manual first step to replacing front CPS - Remove engine,,,,,,,,,,,,,,,,

Good work though. You had so many threads I missed this one.

 

Hi Warrjon

You'll never know just how much reading that has Cheered me up!

As trying to thread that CPS Wire through a hole that just doesn't seem to exist, is a Nightmare of epic proportions and there are no alternatives!

If it doesn't go back through the same hole that you took it out of, then the Wire won't be long enough to connect it to the loom where other passageways that you attempt to thread it through will leave you with a wire that is too short

So maybe it's not just me then?

But out of all the Jobs I've ever done on my Car so far, this one has to be up there with the most complicated of them all and not one I would ever want to attempt to do by the side of the road

Is there some sort of extension lead with a plug on each end, that you can buy to lengthen that wire so you can at least then get yourself home in a breakdown situation

 

OB
Is it possible to slot the bracket and secure the wire in the slot with a cable tie or grommet? Not that you will want to go in there again any time soon!