1992 Jaguar XJR-S
Discussion
craigjm said:
Based on that I would be doing a massively in depth service of the engine. A neglected V12 is an expensive beast when it finally spits the dummy
Yes I've come to the same conclusion. I'm going to go over every inch of it. I've been busy on David Manners today ordering bits. The problem is I cannot know if one shaved ape has just buggered up two or three things over the last 24 years, or if it's been subjected to a prolonged period of abuse at the hands of said shaved ape. FWIW the paperwork with the car suggests previous owners have not been shy with their wallets, but that's no guarantee of the quality of work whatsoever.
I've had a very productive boxing day afternoon with the car. The car came with a 2nd ignition amplifier which I've now "reconditioned" with new components and fitted to the car, the original can live in the boot as a spare. The LHS headlight didn't work on full beam so I went to change the bulb and found the spring clip was missing. Removed the headlamp unit (fiddly job) to see if the spring was in the cavity and change the bulb, but no joy. It stays in place pretty firmly from the rubber boot but I'll have to try and find a spring clip from somewhere. It gave me an opportunity to clean out the grime from the cavity so I took the LHS one out next to do the same.
The bulb was fine, it was the fuse for the LHS full beam that had gone. I've replaced both bulbs with uprated ones anyway. Sadly the dual coil conversion parts from David Manners have not arrived yet. My friend is dropping round tomorrow with his borescope so I can have a look at the insides of the engine, out of idle curiosity.
The bulb was fine, it was the fuse for the LHS full beam that had gone. I've replaced both bulbs with uprated ones anyway. Sadly the dual coil conversion parts from David Manners have not arrived yet. My friend is dropping round tomorrow with his borescope so I can have a look at the insides of the engine, out of idle curiosity.
dme123 said:
My friend is dropping round tomorrow with his borescope so I can have a look at the insides of the engine, out of idle curiosity.
Beats watching Christmas telly.Something truly appealing about cars like this, which seem to span the days of cars being simple beasts pre 80s, to the complex computerbeasts of the 90s onwards.
DaveCWK said:
Random question - Do any of the 6.0 Zytek owners in this thread know how the ECU senses crank/cam position? Does it have a trigger wheel on the crank pulley?
My XJS hasn't moved in 5 months now. This thread is useful motivation to try & find the time!
Hall sensors in the distributor I believe - it's a modified Lucas one rather than the later Marelli. The gearbox bellhousing lacks the fitting for the crank position sensor the Marelli system uses. I will check the docs to confirm this.My XJS hasn't moved in 5 months now. This thread is useful motivation to try & find the time!
Yep, gets both sync and engine speed from the distributor. What model XJS do you have?
Edited by dme123 on Tuesday 27th December 14:10
LewG said:
Whilst you're going aftermarket slap on a couple of turbos and away you go 
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.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.
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 b
d 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 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!
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.
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!
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!
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
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
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!
k" 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
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
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
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. 
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.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.
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.
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.
te 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.
Thanks both - LewG I'll re-read your thread as I followed it first time round and must have forgotten about the headliner. The ones I've been looking at are on some sort of GRP backing rather than cardboard so hopefully won't just go sad like the original.
Feeling sad that the car now has an unsightly blemish over the rear wheel arch. I think I will pull the paintwork remediation work forward and get it all sorted ready for spring/summer. Best make sure my wallet can open up nice and wide.
Feeling sad that the car now has an unsightly blemish over the rear wheel arch. I think I will pull the paintwork remediation work forward and get it all sorted ready for spring/summer. Best make sure my wallet can open up nice and wide.
My kids keep howling in protest every time I force them into the back seats of the XJS, having actually gotten in there myself I now see why.
Combined with a house renovation project I think I'm going to make a very half arsed attempt to sell it, that will start and finish with asking anyone on here who might be interested to give me a shout. Obviously it won't break my heart if I try my very best but it just won't sell...
Combined with a house renovation project I think I'm going to make a very half arsed attempt to sell it, that will start and finish with asking anyone on here who might be interested to give me a shout. Obviously it won't break my heart if I try my very best but it just won't sell...
craigjm said:
I was always amazed at the limited rear space in the XJS compared to the XJC that I have. A six footer can sit behind a six footer in the XJC.
Shame you are looking to sell
Shame you are looking to sell
That's with the front seat in the right place for me. I'm a short arse at about 5'7" on a good day.
After deciding that the sensible thing to do was to sell it I took it out for a midnight drive up through the Brecon Beacons. I was being foolish, I shall keep it and continue with my original plans. Taking that V12 up over 6000 RPM with the windows down on an empty road reminded me why it's worth shovelling money at.
craigjm said:
Good man! the v12 gets under your skin! I have decided to keep mine in situ in my refurb but I might look to LPG it
Would it be possible to use an LPG system that replaces rather than piggy backs off the Zytek? Two birds with one stone. I don't know if LPG ECUs are sophisticated enough to handle ignition at all, let alone ignition and injection for 12 cylinders.Gassing Station | Readers' Cars | Top of Page | What's New | My Stuff