93EXCivic
93EXCivic SuperDork
7/15/11 1:22 p.m.

What is like to live with one of these cars? I have always loved the V12 models. I know the '81-'90 XJS had a Turbo 400. How hard is it swap to a 700R4? Also I noticed the Euro models had 295hp and the American models had 263hp. What made difference? And yes I know V8 swaps are easy but no I don't want one.

Schmidlap
Schmidlap HalfDork
7/15/11 3:49 p.m.

Everyhing you ever wanted to know about the XJS.

http://www.jag-lovers.org/xj-s/book/Jaguar.html

(for some reason I can't get the link to work properly so you'll have to copy and paste - sorry - nevermind, it seems to be working now, I think).

It's big but it should answer all of your questions.

Bob

Stealthtercel
Stealthtercel HalfDork
7/15/11 10:56 p.m.

Without prejudice to what's in Schmidlap's link, I would say the biggest thing to know about XJ-S's is that they seem to rust, badly, in places you cannot even imagine. Jaguar World magazine (link) has done some in-depth stuff on restoring an XJ-S; it's very informative, but I have to say my reaction was "Run, do not walk" from some of the stuff they obviously considered just normal Jaguar repair.

Then, once you get it running and safetied, you can visit The Driven Man (link) for goodies to make it better.

1988RedT2
1988RedT2 Dork
7/16/11 7:32 a.m.

A Jaguar is the automotive equivalent of a smokin' hot woman with a walk-in closet full of issues. You get seduced, then it's OMGWTF?

Basil Exposition
Basil Exposition Reader
7/16/11 8:17 a.m.

Had a '88. It was my daily driver for several years in the late 90's. It took a lot of maintenance, but nothing I couldn't do myself with the help of the Book cited above (to which I contributed). Finally had the dreaded engine fire and it was never right after that. I couldn't sell it so ended up donating it for the tax deduction. I don't regret owning it, but I wouldn't have another one, particularly with gas at $4 a gallon.

Agree that you should get the youngest, lowest mileage one you can find, then be prepared to work on it constantly. It will wear you out eventually and you'll pass it on to the next guy that wants to own a V12 car for a (brief) time in his life.

littleturquoiseb
littleturquoiseb HalfDork
7/16/11 8:32 a.m.

I can add nothing to this thread but I remember very clearly from the sales brochure when I was 14 it claimed to have .... "seemingly endless reserves of power" from the "smooth V-12".

For some reason I liked how that sounded.

Stealthtercel
Stealthtercel HalfDork
7/16/11 10:42 a.m.

I don't want to sound like Debbie Downer, but – besides the whole rust thing – I'd just like to point out that people are talking about "I had THE engine fire," not "I had AN engine fire."

That said, I have driven a V12 Jag sedan, and, yes, the endless reserves of power were pretty nice.

Aeromoto
Aeromoto New Reader
7/16/11 12:12 p.m.

A 700r4 swap is unlikely unless you find an adapter. The bell housing pattern is unique to Jag. The turbo 400s they used were built with the Jag bell pattern. I had an 84 V-12 XJS for a while. It was great when it wanted to run right. It was very smooth and quiet, and it was fast at high speeds, but it was very lazy from a standing start due to its 4000 lb wieght. It's very difficult to work on, and the parts are stupid expensive even though much of it was made by GM. I forget who, but I know someone out there is making a T-5 adapter that uses the 3rd gen Camaro/Firebird world class 5 speed.

coll9947
coll9947 Reader
7/16/11 1:02 p.m.

Jags That Run has a mount kit and conversion manuals for a SBC swap. I keep it bookmarked just in case I find a super clean no-rust non-running example on CL in my area after a successful weekend at the craps table. (two things that will never happen at the same time, so i'm okay.)

Group 44's XJS keeps me awake at night, just dial it down for the street and I'm in heaven.

Travis_K
Travis_K SuperDork
7/16/11 1:34 p.m.

Why not buy a Mercedes 560SEC? It seems like much the same type of car with no where near the problems. You can even swap a diesel into an SEC and make it even more awesome. lol They are cheap too, I have seen driveable ones for $1k.

93EXCivic
93EXCivic SuperDork
7/16/11 6:26 p.m.
Travis_K wrote: Why not buy a Mercedes 560SEC? It seems like much the same type of car with no where near the problems. You can even swap a diesel into an SEC and make it even more awesome. lol They are cheap too, I have seen driveable ones for $1k.

Because I don't like the MB.

Curmudgeon
Curmudgeon SuperDork
7/16/11 11:46 p.m.

Um, yeah. The 560 is every bit the money pit an XJS can be (just price a fuel distributor, common failure) and is nowhere near as pretty.

Travis_K
Travis_K SuperDork
7/17/11 4:29 a.m.

Are the Mercedes V8s really that bad? I probably see 50 w126 V8s for every XJS. I really don't like car fires, and I actually like how the SEC looks, that's why I mentioned it.

carzan
carzan HalfDork
7/17/11 11:15 a.m.
racinginc215 wrote: The real issue is the Mercedes is just plain boring. an XJS is a beautiful and will make you contemplate suicide. it's kinda like a supermodel that's cheating on you.

Meh. Comparing the two:

Yeah, the Mercedes is more boxy and conventional-looking, but I'd hardly call it "boring". If I found out that I had received an inheritance that included a choice between the two, as much as I like the XJS. I'm pretty sure I'd go for the Mercedes.

belteshazzar
belteshazzar SuperDork
7/17/11 12:08 p.m.

most XJS's look more or less like the picture you posted. in my experience, not a lot of the w126's look like that black one.

Travis_K
Travis_K SuperDork
7/17/11 1:35 p.m.

I would say that is a typical example of what I was talking about. Not that I dislike the jaguar, but I would never pick an xj12 over an sec in the same condition for close to the same price.

carzan
carzan HalfDork
7/17/11 2:22 p.m.
belteshazzar wrote: most XJS's look more or less like the picture you posted. in my experience, not a lot of the w126's look like that black one.

Around here, a lot of the coupe w126s DO look like that (not to say there are a lot of coupes left at all). I wasn't trying to make one look better than the other. I was trying to illustrate that both look great and neither look boring in my eyes. I actually prefer the XJS without the cladding and don't think the white one posted above is an improvement over the one I posted. To each his own.

As far as why I would choose the Mercedes over the Jag has as much to do with my experience with both as it does with their looks.

Travis_K
Travis_K SuperDork
7/17/11 2:56 p.m.

If I was going to have a Jaguar driver I would want one of those. IMO its the best looking that could still be a (as much as possible for a Jaguar at least) daily driver.

Curmudgeon
Curmudgeon SuperDork
7/17/11 3:20 p.m.

A lot of the 1980's Mercedes are having problems with the ethanol blended fuel available now. The CIS fuel distributor internal seals do NOT like ethanol and those seals are not available as a service part. There's companies doing rebuilds of the cast iron and a few of the aluminum fuel distributors for a reasonable price but if you have the bad luck to have one that's not available reman, you are talking $2500-$3000 for a fuel dizzy- IF you can find it. The Jag's more modern multipoint EFI can have later ethanol resistant injectors installed, so it gets points for at least giving the average guy a chance at making it work.

Then there's the 'environmentally friendly' Mercedes wiring insulation that just crumbles and falls off when touched. You really don't want that to happen; it can roast the fuel injection control unit. (Yes, CIS does have an electronic controller.) Again they are rare reman and new are about the same price as the fuel dizzy. Those cars are dying off due to the cost of that type repair.

I really like that XJ coupe.

Travis_K
Travis_K SuperDork
7/17/11 3:50 p.m.

Hmm ok, I have a diesel W126, but I don't know much about the gas ones. From the sound of that, (and the fact that the fuel economy is rather unimpressive), i will probably keep it that way. The only mercedes I really like that much (W116 and W126 4 door) are common with diesels anyway. lol I have seen a few diesel swapped SECs, that seems like it would make a pretty nice GT car.

stuart in mn
stuart in mn SuperDork
7/17/11 5:55 p.m.

You need to watch this week's episode of Top Gear UK...Jeremy uses those "seemingly endless reserves of power" to turn an XJS into a locomotive.

MadScientistMatt
MadScientistMatt Dork
7/17/11 5:55 p.m.
Curmudgeon wrote: Um, yeah. The 560 is every bit the money pit an XJS can be (just price a fuel distributor, common failure) and is nowhere near as pretty.

Is there really any such thing as a late '80s V12 powered car that isn't a potential money pit?

Other than some Italian exotics, the only other example I can think of is the BMW 750 / 850. And the way those cars had four separate powertrain control units communicating over a primitive network tends to make them an electronics nightmare.

mad_machine
mad_machine SuperDork
7/17/11 7:13 p.m.

well.. BMW treated the V12 as two joined I6s as far as fuel injection and spark is concerned... so it might actually be easier to diagnose if you treat it as such.

Of course all of these cars are old enough that Megasquirt is an option

carzan
carzan HalfDork
7/17/11 8:32 p.m.
Curmudgeon wrote: A lot of the 1980's Mercedes are having problems with the ethanol blended fuel available now. The CIS fuel distributor internal seals do NOT like ethanol and those seals are not available as a service part. There's companies doing rebuilds of the cast iron and a few of the aluminum fuel distributors for a reasonable price but if you have the bad luck to have one that's not available reman, you are talking $2500-$3000 for a fuel dizzy- IF you can find it. The Jag's more modern multipoint EFI can have later ethanol resistant injectors installed, so it gets points for at least giving the average guy a chance at making it work. Then there's the 'environmentally friendly' Mercedes wiring insulation that just crumbles and falls off when touched. You really don't want that to happen; it can roast the fuel injection control unit. (Yes, CIS does have an electronic controller.) Again they are rare reman and new are about the same price as the fuel dizzy. Those cars are dying off due to the cost of that type repair. I really like that XJ coupe.

You'd have to elaborate on the fuel distributors that cost $2500-$3000. I haven't found one for a w126 coupe that I can't get for ~$500+core/shipping or less. I would expect to have to spend that on a cheap-priced old Merc (or Jag) fuel system anyway.

As for the wiring, w126 production ended the same year they started using the biodegradable wire, so I can't imagine many, if any, are affected.

calvindoesntknow
calvindoesntknow
12/5/11 8:36 p.m.

ive got a 1987 jaguar xjs, i rebuilt the v12 and mated it to a t5 from a cobra mustang, love the xjs body style, just hate the giant rubber bumpers

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