1992 Jaguar XJR-S

Author
Discussion

LewG

1,358 posts

146 months

Wednesday 28th December 2016
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Whilst you're going aftermarket slap on a couple of turbos and away you go biggrin
How are you getting on with it dme? For all my old XJS's foibles I still miss how special it felt, must admit I have been browsing the classifieds and seen a few lovely cars out there for sale. They have shot up in value an awful lot in the year and a half I've been without one though!
It never gave me any trouble but to me the biggest annoyance with mine was the 3 speed GM auto, never really allowed you to exploit that fabulous engine unless holding it in 1st or 2nd, and as has been said the revs at cruise were realistically a bit high.

anonymous-user

Original Poster:

54 months

Wednesday 28th December 2016
quotequote all
LewG said:
Whilst you're going aftermarket slap on a couple of turbos and away you go biggrin
How are you getting on with it dme? For all my old XJS's foibles I still miss how special it felt, must admit I have been browsing the classifieds and seen a few lovely cars out there for sale. They have shot up in value an awful lot in the year and a half I've been without one though!
It never gave me any trouble but to me the biggest annoyance with mine was the 3 speed GM auto, never really allowed you to exploit that fabulous engine unless holding it in 1st or 2nd, and as has been said the revs at cruise were realistically a bit high.
Enjoying the car enormously, it always feels like a sense of occasion when driving it. It hasn't had as much use as I'd like recently because of time commitments and poor weather. I'm starting to make plans to get the wings replaced and front end resprayed early in the new year, and I'll replace the headlining at the same time to get the cosmetics up to scratch. As the PO before CharlesDeGaulle said it's a car you can use and enjoy rather than a garage queen, and I'd like to keep it that way.

The GM gearbox is definitely the weak link and means the car is either quite stately in it's progress, or absolutely full on with no real ability to go for the middle ground. The 4 speeder in my XJ6 and previous XJ12 was better in this regard but still far from perfect. The near 2 second response to kickdown renders is all but useless, I just shift manually if I want to make progress.

The XJRS engine is noticeably less smooth and more vocal than even the factory 6.0, which was itself never as smooth and quiet as the 5.3. Not sure if it's down to the cosworth pistons, the sports exhaust, or some function of the engine management system. Idle quality is not as good as you'd expect either, and contemporary reviews of the XJRS commented on this.

The Zytek system was pretty impressive for the time, with full sequential control of injection for 12 cylinders and a 12 x 24 map for load x speed. With 338bhp it is more powerful than even the late 6.0 X300 with it's Denso distributorless ignition and Lucas 36CU ECU (which still used batch injection). With a manual gearbox I think it would be absolutely wonderful.

In many ways it is a laughably terrible car, even for 1992, and I take my hat off to the mad bd who decided it was the best way to spend nearly £50k. It really is like nothing else to drive and I love it.

Edited by dme123 on Wednesday 28th December 23:51

Spinakerr

1,178 posts

145 months

Thursday 29th December 2016
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Really love this thread - brings back rose-tinted memories of my manual 3.6 that was, unfortunately, a colander.



Given this is the R variant, have you considered a Tremec TKO500 (or similar) conversion? I realise it would be huge expense but if it is a keeper, I wouldn't be able to rest until it was manual and I was winding my way through southern Europe...

Perhaps something to consider once you're completely sure the bodger's misdeeds have been uncovered.

anonymous-user

Original Poster:

54 months

Thursday 29th December 2016
quotequote all
Spinakerr said:
Really love this thread - brings back rose-tinted memories of my manual 3.6 that was, unfortunately, a colander.



Given this is the R variant, have you considered a Tremec TKO500 (or similar) conversion? I realise it would be huge expense but if it is a keeper, I wouldn't be able to rest until it was manual and I was winding my way through southern Europe...

Perhaps something to consider once you're completely sure the bodger's misdeeds have been uncovered.
Hi. I have considered it, it would be a pretty big investment to go to manual but would transform the car. It's on the long term wishlist!

Jimbeaux

33,791 posts

231 months

Thursday 29th December 2016
quotequote all
dme123 said:
LewG said:
Whilst you're going aftermarket slap on a couple of turbos and away you go biggrin
How are you getting on with it dme? For all my old XJS's foibles I still miss how special it felt, must admit I have been browsing the classifieds and seen a few lovely cars out there for sale. They have shot up in value an awful lot in the year and a half I've been without one though!
It never gave me any trouble but to me the biggest annoyance with mine was the 3 speed GM auto, never really allowed you to exploit that fabulous engine unless holding it in 1st or 2nd, and as has been said the revs at cruise were realistically a bit high.
Enjoying the car enormously, it always feels like a sense of occasion when driving it. It hasn't had as much use as I'd like recently because of time commitments and poor weather. I'm starting to make plans to get the wings replaced and front end resprayed early in the new year, and I'll replace the headlining at the same time to get the cosmetics up to scratch. As the PO before CharlesDeGaulle said it's a car you can use and enjoy rather than a garage queen, and I'd like to keep it that way.

The GM gearbox is definitely the weak link and means the car is either quite stately in it's progress, or absolutely full on with no real ability to go for the middle ground. The 4 speeder in my XJ6 and previous XJ12 was better in this regard but still far from perfect. The near 2 second response to kickdown renders is all but useless, I just shift manually if I want to make progress.

The XJRS engine is noticeably less smooth and more vocal than even the factory 6.0, which was itself never as smooth and quiet as the 5.3. Not sure if it's down to the cosworth pistons, the sports exhaust, or some function of the engine management system. Idle quality is not as good as you'd expect either, and contemporary reviews of the XJRS commented on this.

The Zytek system was pretty impressive for the time, with full sequential control of injection for 12 cylinders and a 12 x 24 map for load x speed. With 338bhp it is more powerful than even the late 6.0 X300 with it's Denso distributorless ignition and Lucas 36CU ECU (which still used batch injection). With a manual gearbox I think it would be absolutely wonderful.

In many ways it is a laughably terrible car, even for 1992, and I take my hat off to the mad bd who decided it was the best way to spend nearly £50k. It really is like nothing else to drive and I love it.

Edited by dme123 on Wednesday 28th December 23:51
Nice ride dme. smile I agree with your engine description. My 4.0 XJS is no 0-60 winner; however, from 45-110, I have seen few things make that leap quicker and, as you said, "linear".

anonymous-user

Original Poster:

54 months

Friday 30th December 2016
quotequote all
In case anyone is interested, the pic below is of the insides of a 4-wire Lucas AB14 ignition amp. The XJS with Lucas ignition used the 6-wire version, which has a little resistor pack and two extra wires to provide a feed for the tacho and the ECU. The XJR-S doesn't use these extra wires, and from the factory the extra two wires were just joined together. This means that I can use the somewhat cheaper 4-wire version to replace it.

The only component of note is that black bent thing - a standard GM HEI ignition module that is about $30 off the shelf in the US, and available relatively cheaply here. It was designed for 8 cylinder engines that could rev to maybe 5500RPM so it's no wonder they die quite easily in a 6500RPM 12 cylinder engine. Uprated modules are available so I might give it a try.

In the interests of originality I transferred the HEI module and capacitor from a nice new AB14 into the casing of my old amp and kept the resistors and extra two wires.

If you have one that dies I would highly recommend picking up a new HEI module and replacing that first. These amps are quite expensive from Jaguar and the only component likely to fail is the module. I tested the 22 year old 1mF capacitor and it still measured at 1mF.



Oh and I also found this in the boot. It's meant to have an opening in the carpet under the CD changer to get it out, but mine didn't have an opening so I assumed no tool kit. I took off the carpet to have a look inside and it was hiding there all along!


RC1807

12,532 posts

168 months

Friday 30th December 2016
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Tool kit is a nice find. Is there a tool missing from the top right?

anonymous-user

Original Poster:

54 months

Friday 30th December 2016
quotequote all
RC1807 said:
Tool kit is a nice find. Is there a tool missing from the top right?
I think there was a touch up paint kit there from internet pics.

anonymous-user

Original Poster:

54 months

Sunday 1st January 2017
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I took the car out for a proper drive for the first time in weeks, and the first time since replacing the ignition amplifier. Under anything but light acceleration it was pinking like crazy. "fk" thinks I.

A bit of research suggests that when driven gently around town a lot the V12 does suffer from detonation once you push it, and in fact it says as much in the handbook. I also read from Mr. Bywater at AJ6 engineering who was involved in the engineering of the engine that they tested it extensively with a lot of induced detonation with no ill effects.

Very Jaguar to make an engine than pinks and just shrug it off hehe

Emboldened by this advice I took the car back out and gave it the mother of all italian tuneups, lo and behold once I had "full explored" the rev range in 2nd it stopped completely. The harder and longer I drove the car the better and better it performed, I gave it absolute hell for 40 miles and it just kept getting sweeter and sweeter.

Lesson learned, no more mincing about in it, it likes it rough biggrin

Having now conferred with other V12 XJS owners apparently this is not at all uncommon.

ETA - have now spoken to a fellow XJR-S owner who says the clicking I heard might not have been pinking, but rather ignition arcing in the damp air. He says his always misfires if you give it too much throttle when it's cold and also makes that noise. I don't believe it was misfiring though, it still felt smooth. I think when I change the coils next week I'll take all the leads out and have a good look at them. Interestingly this chap also has all the Zytek kit to speak to the ECU!

Edited by dme123 on Sunday 1st January 21:28

craigjm

17,955 posts

200 months

Sunday 1st January 2017
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My car is epic locked in second and just booting it although mpg goes down about as fast as a beer at Ollie Reeds house

finlo

3,761 posts

203 months

Sunday 1st January 2017
quotequote all
RC1807 said:
Tool kit is a nice find. Is there a tool missing from the top right?
Top right?

anonymous-user

Original Poster:

54 months

Sunday 1st January 2017
quotequote all
craigjm said:
My car is epic locked in second and just booting it although mpg goes down about as fast as a beer at Ollie Reeds house
Yeah the fuel needle was going down visibly minute by minute. Trip computer is currently reporting 11mpg.

Jimbeaux

33,791 posts

231 months

Sunday 1st January 2017
quotequote all
I remove and clean my EGR valve at least yearly. Easy to do. There is a recall that replaces the valve and puts a chip in the computer to cause a cleaning cycle. Screw that, that sounds like trouble. I also spray through some deadpan one a year and blow the crap out of the throttle body that accumulates in there. Runs like a charm and fixes most all check engine lights. smile

anonymous-user

Original Poster:

54 months

Monday 2nd January 2017
quotequote all
Jimbeaux said:
I remove and clean my EGR valve at least yearly. Easy to do. There is a recall that replaces the valve and puts a chip in the computer to cause a cleaning cycle. Screw that, that sounds like trouble. I also spray through some deadpan one a year and blow the crap out of the throttle body that accumulates in there. Runs like a charm and fixes most all check engine lights. smile
Mercifully no EGR on UK models, and no air injection either. I didn't realise that force feeding the engine it's own excrement caused problems with petrols as well as diesels.

Jimbeaux

33,791 posts

231 months

Monday 2nd January 2017
quotequote all
dme123 said:
Jimbeaux said:
I remove and clean my EGR valve at least yearly. Easy to do. There is a recall that replaces the valve and puts a chip in the computer to cause a cleaning cycle. Screw that, that sounds like trouble. I also spray through some deadpan one a year and blow the crap out of the throttle body that accumulates in there. Runs like a charm and fixes most all check engine lights. smile
Mercifully no EGR on UK models, and no air injection either. I didn't realise that force feeding the engine it's own excrement caused problems with petrols as well as diesels.
Yes, the XJS is prone to cumulative throttle body buildup. I meant "Seafoam" as a spray cleaner in my post but was "autocorrected". smile

anonymous-user

Original Poster:

54 months

Monday 9th January 2017
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Not relating to my car directly, but I had to walk from Euston to Farringdon at about 7:10am this morning and saw all sorts of interesting cars on the way. 2nd place sighting was probably a Rolls Royce Wraith in black, which really did not look great from the rear quarter to my eye.

1st place was an M plate XJS Convertible, 4 litre from the lack of V12 badging and tailpipe shapes. It really did stand out with it's very simple surfaces and positively dainty size. The latter was the most surprising thing, it really did look like a small car in London traffic.


anonymous-user

Original Poster:

54 months

Friday 13th January 2017
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I've just noticed that at some point in the last day or two some utter gobste has scraped the NSR wheel arch rim. I've polished off the very worst of it but it's turned the clearcoat rough and I don't think it'll polish out.

I've resolved not to get angry but to consider it even shabbier chic until I get it fixed along with the other paintwork issues.

I've also noticed that The Bodger has attempted to fix the headlining and broken/lost practically every retaining clip on the A/B post trim doing it. Another job for the list, it needs a new headliner and I had already decided to order a full set of clips as I was sure they'd all break anyway.

craigjm

17,955 posts

200 months

Friday 13th January 2017
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Jaguar only learnt how to make a headlining that stayed in place about 2002 when they launched the X350 XJ haha

Jimbeaux

33,791 posts

231 months

Friday 13th January 2017
quotequote all
craigjm said:
Jaguar only learnt how to make a headlining that stayed in place about 2002 when they launched the X350 XJ haha
That is a truism. If mine droops once more, I swear I will spray tan Rhino-Liner up there. biggrin

anonymous-user

Original Poster:

54 months

Friday 13th January 2017
quotequote all
There are companies that sell DIY kits that come with the headliner attached to a board ready to go straight in, and the YouTube videos make installation look quite easy (of course). I'd love to hear any 1st hand experience of this, it all seems too good to be true.