before and after

[V12Smig]

Update..... so its been a few months since I've had her back and she is still not running correctly, finally have managed to get it booked in to be assessed end of January. The big thing I would like to point out is how busy everyone seems to be, I have had awful issues getting a specialist to look at my V12, hopefully she will be ready for the Brooklands Centenary.

[mike020150]

Fingers crossed! Mike.

[V12Smig]

Hi Guys this is not going too well. Basically something is not quite right with the car, the engine is fine, distributor fine, several ECU's given the same result. Basically she is struggling to rev at heavy throttle loads, we think their is an issue with the vacuum wiring and connections. Ideally I like to borrow someone's XJ12/ XJS pre 1988 and park it next to mine so that we can compare ? Is there anyone in the Guildford/Woking area that may be able to help? May need the car parked up for a couple of days, inside of course..

[Andy P]

Hi V12Smig,
Sorry to hear your having problems.
Must be very frustrating for you.
I see that Tom Lenthal is quite close to you,I understand he knows a thing or two about the Jaguar V12 engine.
Not sure how approachable he is but might be worth a phone call.
I'm sure you'll get it sorted out.
Take care and good luck.
Andy

[V12Smig]

Hi Andy,
Tom actually fitted the the engine and gearbox, connected everything and then threw the car back to me saying he cant do any more unless I spend 10k on new ignition/injection system, ECU and parts.. seems as if his knowledge only went so far... extremely disappointing and I feel a tad mug'd off to be honest with you.

[Andy P]

Ahhh that's pretty poor of him .
Sorry for bringing back such bad memories.
I'd feel the same as well,so much for helping out fellow club members then.
I'm sure you'll get it sorted one way or another.
Take care and good luck.
Andy

[V12Smig]

No worries... Its at another specialist, who is having issues as well... greeted with yes, we know these well, then after a few weeks "mmmm, well we haven't seen one of these in a while and really need another one next to it to check if everything is as it should be?" hence my request. Doubt I'll even make it to the Le Man classic let alone the Brooklands centenary. Its runs, ticks over smoothly (@750 rpm) but is having issues revving everything checks out... loosing patience and too much money now.

[ptjs1]

V12Smig,

Sorry to hear about the problems. You said that your distributor is rebuilt but also mentioned continuing problems getting it timed correctly. Did you resolve that?

There's a similar thread on jaguarforums.com about a guy who had similar problems revving above 3000rpm. His is a Marelli not a Lucas car, but worth reading for some pointers. There are some usual problems on inability to run at higher revs ev up that may be worth investigating:

- Are both coils installed correctly? A Lucas car can run ok on one coil but will struggle to rev above 3k
- A blocked or collapsing fuel filter. Fuel pressure on rail could be ok, but the filter may not flow enough volume at higher revs
- Clogged or collapsing cat on one side. Will run ok at low revs but struggle at higher revs
- Timing problem, but you mentioned weights were functioning OK?
- Faulty FPRs on one or both banks.
- Swirl pot sediment ( do you have one on your car?) Fuel flows ok at low revs but can't manage the volume at higher revs
- Coil or plug lead breakdown. But I assume they are all new?

I'll post link to the other thread later.

Cheers

Paul

[V12Smig]

Thank You Paul for your advice. Thankfully the issue has been traced to faulty and incorrect vacuum plumping and a few component failures.. will report back when I have the car...

[Andy P]

That's good news after all the trouble shooting you have been doing.
Lets hope this helps resolves the problem.
Good luck,keep at it.
Take care.
Andy

[V12Smig]

Hi All, quick up date,
the car runs very well now, the engine is strong and purrs at idle, oil pressure strong, amperage charge good, temp constant!
The manual box has transformed the cars performance, the AJ6 big bore pipes has totally changed its character, until I get it in to fourth/5th when she purrs along!
I am getting rather too much resonance on the stainless down pipes, its very noticeable in the cabin. Their obviously a thin wall stainless. Does anyone have any ideas how to calm this down.. sure when its coke up a bit it will be less noisy, but was thinking of wrapping down pipes in exhaust tape.... anyone have experience here...
She's still not MOT'd as I have a few wiring issues, lights and indicators blinking in unison but getting this looked at next week...
more updates when they arrive..

[mike020150]

Sounds promising for an enjoyable summer! Mike.

[V12Smig]

Finally, MOT'd and taxed... Took it for its first legal run yesterday and I am very happy its back on the road.. will post some pics in due course.
Looking forward to the drive to Le Man classic now.

[V12Smig]

Update for all those that are interested... So the purpose of getting the Jag fixed was the trip to Le Mans classic, thankfully covid gave me time to fix it properly. The engine and manual gearbox worked fine, the manual gearbox, together with the AJ6 big bore exhaust and ECU totally transforming the cars attitude, which I am happy with, although some purists found it uncouth! The aircon was cold, the old clarion connected to my iPhone, oil pressure amperage and temp spot on!
Its amazing how capable the old girl still is, bullet straight at a ton with so much torque you rarely need to change down from 5th even if its a tad long legged.
Only issue was on Saturday when the starter didn't want to play ball, wouldn't click at all. Got a push and she started and then drove around a bit to try and find a spare starter or solenoid, almost immediately came across a chap parked up in a lovely XJS eventer, with assistance on the side. His name was Charles and he said he wasn't offering assistance but just put the stickers on the side of the car for Le Mans. Came across the only other XJ, a series 1 manual 4.2 with the bonnet up, the guy Bertiebloke was rebuilding his carbs, he actually had a new spare starter but it wasn't compatible . After this drive the starter worked fine.
Was blown away at the attention she got all the way there and back and at the camp site.
Had a good drag race away from the Paege with a Cayman GT4, his face was not happy that I managed to edge forward every time he changed gear...
Got home with fuel ended up costing 50p a mile!!! luckily managed to share those costs with my 2 passengers.
Next thing is to try and raise the ride height a tad and dial in some refinement that I have lost due to my fettling, oh and I seriously need a brake upgrade... yellow stuff pads and standard callipers not up to the performance now available... any suggestions?

[mike020150]

Once you start going faster than Jaguar intended, lots of things need to be upgraded. On the braking side, don't forget that modern cars have extremely light brake pedal pressures in comparison with their forebears, like the Series XJs. Yellow stuff pads should be hard enough material although the XJ's weak spot will always be overheating and consequent fading of the rear inboard brakes. If you didn't provoke fading, perhaps you should investigate upgrading the brake servo? If fade troubled you, it is possible to fit vented rear discs. I have a set of suitably spaced rear calipers tucked away in my garage, ready for just such an upgrade one day when I get around to it. Alternatively, a set of rear outboard brakes from a late XJS (if you can find some) would be another way of improving braking at a small cost to ride quality. Mike.